43 results on '"Chan BT"'
Search Results
2. Treatment of chronic back pain using indirect vibroacoustic therapy: A pilot study
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Renly Lim, Einly Lim, Ahmad Khairi Abdul Wahab, Bee Ting Chan, Anwar Suhaimi, Lim, E, Lim, R, Suhaimi, A, Chan, BT, and Wahab, AKA
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spinal degeneration ,Male ,medicine.medical_specialty ,Visual Analog Scale ,Visual analogue scale ,medicine.medical_treatment ,Physical Therapy, Sports Therapy and Rehabilitation ,Pilot Projects ,Vibration ,rehabilitation ,03 medical and health sciences ,Disability Evaluation ,0302 clinical medicine ,Quality of life ,Back pain ,medicine ,Humans ,Orthopedics and Sports Medicine ,In patient ,030212 general & internal medicine ,Functional ability ,Rehabilitation ,business.industry ,Chronic pain ,vibroacoustic therapy ,Middle Aged ,medicine.disease ,Low back pain ,Acoustic Stimulation ,Physical therapy ,Quality of Life ,Female ,medicine.symptom ,Chronic Pain ,chronic pain ,business ,Low Back Pain ,030217 neurology & neurosurgery - Abstract
BACKGROUND: Low frequency sound wave stimulation therapy has become increasingly popular in the rehabilitation fields, due to its ease, less fatiguing and time efficient application. OBJECTIVE: This 12-week pilot study examines the efficacy of applying low frequency sound wave stimulation (between 16-160 Hz) through both hands and feet on relieving pain and improving functional ability in patients with chronic back pain. METHODS: Twenty-three participants with chronic shoulder (eleven participants) or low back pain (twelve participants) underwent a 12-week vibration therapy program of three sessions per week. A low frequency sound wave device comprising four piezoelectric vibration-type tactile tranducers enclosed in separate 5-cm diameter circular plates, which generate sinusoidal vibratory stimuli at a frequency of 16–160 Hz, was used in this study. Primary outcome measure was pain sensation measured using the Visual Analogue Scale (P-VAS). The secondary outcome measures were pain-related disability measured using the pain disability index (PDI) and quality of life measured using the SF-12. RESULTS: At week 12, significant reductions in pain sensation and pain-related disability were observed, with mean reductions of 3.5 points in P-VAS and 13.5 points in the PDI scores. Sixty-five percent of the participants had a reduction of at least 3 points on the P-VAS score, while 52% participants showed a decrease of at least 10 points in the PDI score. Significant improvement was observed in the SF-12 physical composite score but not the mental composite score. CONCLUSIONS: The preliminary findings showed that passive application of low frequency sound wave stimulation therapy through both hands and feet was effective in alleviating pain and improving functional ability in patients with chronic back pain. Refereed/Peer-reviewed
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- 2018
3. Implementation of a Pharmacist-Driven Vancomycin Area Under the Concentration-Time Curve Monitoring Program Using Bayesian Modeling in Outpatient Parenteral Antimicrobial Therapy.
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Gillett E, Aleissa MM, Pearson JC, Solomon DA, Kubiak DW, Dionne B, Edrees HH, Okenla A, and Chan BT
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Background: Current vancomycin monitoring guidelines recommend monitoring 24-hour area under the concentration-time curve (AUC) to minimum inhibitory concentration ratios for patients with serious methicillin-resistant Staphylococcus aureus infections. However, there are sparse data on the safety, feasibility, and efficacy of vancomycin AUC monitoring for outpatients. Traditional AUC pharmacokinetic calculations require 2 concentrations, while bayesian software allows for single-concentration AUC estimations., Methods: We conducted a single-center, quasi-experimental, interrupted time series study of patients enrolled in the outpatient parenteral antimicrobial therapy program at our institution for vancomycin management. Our institution implemented a pharmacist-driven vancomycin AUC monitoring program from September 2019 to February 2020, and again from September 2022 to March 2023. Patients enrolled underwent vancomycin monitoring using an AUC goal of 400-600 mg⋅h/L, estimated through bayesian modeling. Patients enrolled in the outpatient parenteral antimicrobial therapy program from July 2021 through August 2022 for trough-based monitoring were used for comparison. The primary outcome was nephrotoxicity incidence, defined as a serum creatinine increase by ≥0.5 mg/dL or ≥50% during outpatient vancomycin therapy., Results: We enrolled 63 patients in the AUC group and 60 patients in the trough-based group. Nephrotoxicity was significantly lower in the AUC cohort (6.3% vs 23.3%; P = .01). The number of unusable vancomycin concentrations was also significantly lower in the AUC cohort (0% vs 6%; P < .01). There was no difference in composite 90-day all-cause mortality or readmission (33.3% vs 38.3%; P = .56)., Conclusions: Following implementation of a pharmacist-driven AUC monitoring program, patients were less likely to develop nephrotoxicity during outpatient vancomycin therapy., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)
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- 2024
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4. Simulating impaired left ventricular-arterial coupling in aging and disease: a systematic review.
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Ding CCA, Dokos S, Bakir AA, Zamberi NJ, Liew YM, Chan BT, Md Sari NA, Avolio A, and Lim E
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- Aged, Humans, Aging, Coronary Vessels, Heart Ventricles, Heart, Ventricular Function, Left
- Abstract
Aortic stenosis, hypertension, and left ventricular hypertrophy often coexist in the elderly, causing a detrimental mismatch in coupling between the heart and vasculature known as ventricular-vascular (VA) coupling. Impaired left VA coupling, a critical aspect of cardiovascular dysfunction in aging and disease, poses significant challenges for optimal cardiovascular performance. This systematic review aims to assess the impact of simulating and studying this coupling through computational models. By conducting a comprehensive analysis of 34 relevant articles obtained from esteemed databases such as Web of Science, Scopus, and PubMed until July 14, 2022, we explore various modeling techniques and simulation approaches employed to unravel the complex mechanisms underlying this impairment. Our review highlights the essential role of computational models in providing detailed insights beyond clinical observations, enabling a deeper understanding of the cardiovascular system. By elucidating the existing models of the heart (3D, 2D, and 0D), cardiac valves, and blood vessels (3D, 1D, and 0D), as well as discussing mechanical boundary conditions, model parameterization and validation, coupling approaches, computer resources and diverse applications, we establish a comprehensive overview of the field. The descriptions as well as the pros and cons on the choices of different dimensionality in heart, valve, and circulation are provided. Crucially, we emphasize the significance of evaluating heart-vessel interaction in pathological conditions and propose future research directions, such as the development of fully coupled personalized multidimensional models, integration of deep learning techniques, and comprehensive assessment of confounding effects on biomarkers., (© 2024. The Author(s).)
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- 2024
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5. Research priorities to reduce the impact of COVID-19 in low- and middle-income countries.
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Polašek O, Wazny K, Adeloye D, Song P, Chan KY, Bojude DA, Ali S, Bastien S, Becerra-Posada F, Borrescio-Higa F, Cheema S, Cipta DA, Cvjetković S, Castro LD, Ebenso B, Femi-Ajao O, Ganesan B, Glasnović A, He L, Heraud JM, Igwesi-Chidobe C, Iversen PO, Jadoon B, Karim AJ, Khan J, Biswas RK, Lanza G, Lee SW, Li Y, Liang LL, Lowe M, Islam MM, Marušić A, Mshelia S, Manyara AM, Htay MN, Parisi M, Peprah P, Sacks E, Akinyemi KO, Shahraki-Sanavi F, Sharov K, Rotarou ES, Stankov S, Supriyatiningsih W, Chan BT, Tremblay M, Tsimpida D, Vento S, Glasnović JV, Wang L, Wang X, Ng ZX, Zhang J, Zhang Y, Campbell H, Chopra M, Cousens S, Krstić G, Macdonald C, Mansoori P, Patel S, Sheikh A, Tomlinson M, Tsai AC, Yoshida S, and Rudan I
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- COVID-19 Vaccines, Child, Humans, Pandemics prevention & control, Research Design, COVID-19 epidemiology, COVID-19 prevention & control, Developing Countries
- Abstract
Background: The COVID-19 pandemic has caused disruptions to the functioning of societies and their health systems. Prior to the pandemic, health systems in low- and middle-income countries (LMIC) were particularly stretched and vulnerable. The International Society of Global Health (ISoGH) sought to systematically identify priorities for health research that would have the potential to reduce the impact of the COVID-19 pandemic in LMICs., Methods: The Child Health and Nutrition Research Initiative (CHNRI) method was used to identify COVID-19-related research priorities. All ISoGH members were invited to participate. Seventy-nine experts in clinical, translational, and population research contributed 192 research questions for consideration. Fifty-two experts then scored those questions based on five pre-defined criteria that were selected for this exercise: 1) feasibility and answerability; 2) potential for burden reduction; 3) potential for a paradigm shift; 4) potential for translation and implementation; and 5) impact on equity., Results: Among the top 10 research priorities, research questions related to vaccination were prominent: health care system access barriers to equitable uptake of COVID-19 vaccination (ranked 1st), determinants of vaccine hesitancy (4th), development and evaluation of effective interventions to decrease vaccine hesitancy (5th), and vaccination impacts on vulnerable population/s (6th). Health care delivery questions also ranked highly, including: effective strategies to manage COVID-19 globally and in LMICs (2nd) and integrating health care for COVID-19 with other essential health services in LMICs (3rd). Additionally, the assessment of COVID-19 patients' needs in rural areas of LMICs was ranked 7th, and studying the leading socioeconomic determinants and consequences of the COVID-19 pandemic in LMICs using multi-faceted approaches was ranked 8th. The remaining questions in the top 10 were: clarifying paediatric case-fatality rates (CFR) in LMICs and identifying effective strategies for community engagement against COVID-19 in different LMIC contexts., Interpretation: Health policy and systems research to inform COVID-19 vaccine uptake and equitable access to care are urgently needed, especially for rural, vulnerable, and/or marginalised populations. This research should occur in parallel with studies that will identify approaches to minimise vaccine hesitancy and effectively integrate care for COVID-19 with other essential health services in LMICs. ISoGH calls on the funders of health research in LMICs to consider the urgency and priority of this research during the COVID-19 pandemic and support studies that could make a positive difference for the populations of LMICs., Competing Interests: Competing interests: Ana Marušić, Harry Campbell and Igor Rudan are the Co-Editors in Chief of the Journal of Global Health. To ensure that any possible conflict of interest relevant to the journal has been addressed, this article was reviewed according to best practice guidelines of international editorial organisations. The authors completed the ICMJE Unified Competing Interests Form (available upon request from the corresponding author) and declare no further conflicts of interest., (Copyright © 2022 by the Journal of Global Health. All rights reserved.)
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- 2022
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6. Correction: TGFβ-activation by dendritic cells drives Th17 induction and intestinal contractility and augments the expulsion of the parasite Trichinella spiralis in mice.
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Steel N, Faniyi AA, Rahman S, Swietlik S, Czajkowska BI, Chan BT, Hardgrave A, Steel A, Sparwasser TD, Assas MB, Grencis RK, Travis MA, and Worthington JJ
- Abstract
[This corrects the article DOI: 10.1371/journal.ppat.1007657.].
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- 2021
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7. Comparison of diametric and volumetric changes in Stanford type B aortic dissection patients in assessing aortic remodeling post-stent graft treatment.
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Wan Ab Naim WN, Sun Z, Liew YM, Chan BT, Jansen S, Lei J, Ganesan PB, Hashim SA, Sridhar GS, and Lim E
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Background: The study aims to analyze the correlation between the maximal diameter (both axial and orthogonal) and volume changes in the true (TL) and false lumens (FL) after stent-grafting for Stanford type B aortic dissection., Method: Computed tomography angiography was performed on 13 type B aortic dissection patients before and after procedure, and at 6 and 12 months follow-up. The lumens were divided into three regions: the stented area (Region 1), distal to the stent graft to the celiac artery (Region 2), and between the celiac artery and the iliac bifurcation (Region 3). Changes in aortic morphology were quantified by the increase or decrease of diametric and volumetric percentages from baseline measurements., Results: At Region 1, the TL diameter and volume increased (pre-treatment: volume =51.4±41.9 mL, maximal axial diameter =22.4±6.8 mm, maximal orthogonal diameter =21.6±7.2 mm; follow-up: volume =130.7±69.2 mL, maximal axial diameter =40.1±8.1 mm, maximal orthogonal diameter =31.9+2.6 mm, P<0.05 for all comparisons), while FL decreased (pre-treatment: volume =129.6±150.5 mL; maximal axial diameter =43.0±15.8 mm; maximal orthogonal diameter =28.3±12.6 mm; follow-up: volume =66.6±95.0 mL, maximal axial diameter =24.5±19.9 mm, maximal orthogonal diameter =16.9±13.7, P<0.05 for all comparisons). Due to the uniformity in size throughout the vessel, high concordance was observed between diametric and volumetric measurements in the stented region with 93% and 92% between maximal axial diameter and volume for the true/false lumens, and 90% and 92% between maximal orthogonal diameter and volume for the true/false lumens. Large discrepancies were observed between the different measurement methods at regions distal to the stent graft, with up to 46% differences between maximal orthogonal diameter and volume., Conclusions: Volume measurement was shown to be a much more sensitive indicator in identifying lumen expansion/shrinkage at the distal stented region., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/qims-20-814). ZS serves as an unpaid associate editor of Quantitative Imaging in Medicine and Surgery. The other authors have no conflicts of interest to declare., (2021 Quantitative Imaging in Medicine and Surgery. All rights reserved.)
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- 2021
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8. HIV-related stigma trends in the general population of India during an era of antiretroviral treatment expansion, 2005-16.
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Chan BT, Chakrapani V, and Tsai AC
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- Adult, Anti-Retroviral Agents therapeutic use, Disclosure, Female, Humans, India, Male, Surveys and Questionnaires, Young Adult, HIV Infections drug therapy, Social Stigma
- Abstract
Background: In India, which has the world's third-largest HIV epidemic, the extent to which levels of HIV-related stigma have changed during an era of ART scale-up is unknown., Methods: We analyzed data from the 2005-06 and 2015-16 National Family Health Surveys (NFHS) to estimate trends in two stigma domains among people in the general population: desires for social distance from people living with HIV (ie, unwillingness to interact) and fear of serostatus disclosure in the case of a hypothetical HIV infection. We fitted multivariable linear probability models to the data with year of NFHS as the explanatory variable and alternately specifying fear of disclosure or desires for social distance as the dependent variable. Analyses were stratified by sex, state, and high vs low HIV prevalence states., Results: We included data on 172 795 women and 159 194 men. Desires for social distance declined in 2015-16 compared with 2005-06 (38% in 2015-16 vs 43% in 2005-06; adjusted b = -0.046; 95% confidence interval (CI = -0.049 to -0.043; P < 0.001) but fear of serostatus disclosure increased (31% in 2005-06 vs 37% in 2015-16; adjusted b = 0.058; 95% CI = 0.055-0.062; P < 0.001). Declines in social distancing were more pronounced among men and in high HIV prevalence states. Increased fear of serostatus disclosure was greater among women and in high HIV prevalence states. There was significant variability in trends disaggregated by state., Conclusions: During the first decade of ART scale-up in India, fear of HIV serostatus disclosure in the general population increased despite a decline in desires for social distance., Competing Interests: Competing interests: The authors completed the ICMJE Unified Competing Interest form (available upon request from the corresponding author) and declare no conflicts of interest., (Copyright © 2020 by the Journal of Global Health. All rights reserved.)
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- 2020
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9. A programme to improve quality of care for patients with chronic diseases, Kazakhstan.
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Chan BT, Rauscher C, Issina AM, Kozhageldiyeva LH, Kuzembaeva DD, Davis CL, Kravchenko H, Hindmarsh M, McGowan J, and Kulkaeva G
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- Chronic Disease, Female, Humans, Kazakhstan, Male, Mentoring, Quality Improvement, Self Care methods, Diabetes Mellitus therapy, Heart Failure therapy, Hypertension therapy, Quality of Health Care, Self Care standards
- Abstract
Objective: To evaluate the effect of a disease management programme in Kazakhstan on quality indicators for patients with hypertension, diabetes and chronic heart failure., Methods: A supportive, interdisciplinary, quality improvement programme was implemented between November 2014 and November 2015 at seven polyclinics in Pavlodar and Petropavlovsk. Quality improvement teams were established at each clinic and quality improvement tools were introduced, including patient flowsheets, decision support tools, patient registries, a patient recall process, support for patient self-management and patient follow-up with intensity adjusted for level of disease control. Clinic teams met for four 3-day interactive learning sessions within 1 year, with additional coaching visits. Implementation was managed by five local coordinators and consultants trained by international consultants. National and regional steering committees monitored progress., Findings: Between July and October 2015, the proportion of hypertensive patients with the recommended blood pressure increased from 24% (101/424) to 56% (228/409). Among patients with diabetes, the proportion who recently underwent eye examinations increased from 26% (101/391) to 71% (308/433); the proportion who had their low-density lipoprotein cholesterol measured increased from 57% (221/391) to 85% (369/433); and the proportion who had their albumin : creatinine ratio measured increased from 11% (44/391) to 49% (212/433). The proportion of chronic heart failure patients who underwent echocardiography rose from 91% (128/140) to 99% (157/158). All patients set themselves self-management goals., Conclusion: This intensive, supportive, multifaceted programme was associated with significant improvements in quality of care for patients with chronic disease. Further investment in coaching capacity is needed to extend the programme nationally., ((c) 2020 The authors; licensee World Health Organization.)
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- 2020
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10. The Convergence of Disclosure Concerns and Poverty Contributes to Loss to HIV Care in India: A Qualitative Study.
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Perlo J, Colocci I, Rajagopal SS, Betancourt TS, Pradeep A, Mayer KH, Kumarasamy N, O'Cleirigh C, and Chan BT
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- Adult, Anti-Retroviral Agents therapeutic use, CD4 Lymphocyte Count, Delivery of Health Care statistics & numerical data, Female, HIV Infections drug therapy, HIV Infections economics, Humans, India epidemiology, Male, Middle Aged, Qualitative Research, Delivery of Health Care standards, Disclosure, HIV Infections epidemiology, Patient Dropouts, Poverty
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In India, there is little evidence on reasons for high rates of loss to HIV care. We conducted a clinic-based qualitative study at the YR Gaitonde Centre for AIDS Research and Education to explore factors that influence loss to care. In all, 17 men and 14 women were interviewed; median age was 42 (interquartile range [IQR], 36-48) and median CD4 count was 448 (IQR, 163-609). A majority reported avoiding treatment freely available at nearby government facilities because of disclosure concerns and perceptions of poor quality. As a result, participants sought care in the private sector where they were subjected to medication and transport costs. Life circumstances causing lost wages or unexpected expenditures therefore prevented participants from attending clinic, resulting in loss to care. Improving perceptions of quality of care in the public sector, addressing disclosure concerns, and reducing economic hardships among people living with HIV may be important in reducing loss to HIV care in India.
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- 2020
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11. TGFβ-activation by dendritic cells drives Th17 induction and intestinal contractility and augments the expulsion of the parasite Trichinella spiralis in mice.
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Steel N, Faniyi AA, Rahman S, Swietlik S, Czajkowska BI, Chan BT, Hardgrave A, Steel A, Sparwasser TD, Assas MB, Grencis RK, Travis MA, and Worthington JJ
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- Animals, Cells, Cultured, Cytokines metabolism, Dendritic Cells cytology, Dendritic Cells parasitology, Intestine, Small parasitology, Male, Mice, Mice, Inbred C57BL, Th17 Cells parasitology, Trichinellosis parasitology, Dendritic Cells immunology, Intestine, Small immunology, Th17 Cells immunology, Transforming Growth Factor beta metabolism, Trichinella spiralis immunology, Trichinellosis immunology
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Helminths are highly prevalent metazoan parasites that infect over a billion of the world's population. Hosts have evolved numerous mechanisms to drive the expulsion of these parasites via Th2-driven immunity, but these responses must be tightly controlled to prevent equally devastating immunopathology. However, mechanisms that regulate this balance are still unclear. Here we show that the vigorous Th2 immune response driven by the small intestinal helminth Trichinella spiralis, is associated with increased TGFβ signalling responses in CD4+ T-cells. Mechanistically, enhanced TGFβ signalling in CD4+ T-cells is dependent on dendritic cell-mediated TGFβ activation which requires expression of the integrin αvβ8. Importantly, mice lacking integrin αvβ8 on DCs had a delayed ability to expel a T. spiralis infection, indicating an important functional role for integrin αvβ8-mediated TGFβ activation in promoting parasite expulsion. In addition to maintaining regulatory T-cell responses, the CD4+ T-cell signalling of this pleiotropic cytokine induces a Th17 response which is crucial in promoting the intestinal muscle hypercontractility that drives worm expulsion. Collectively, these results provide novel insights into intestinal helminth expulsion beyond that of classical Th2 driven immunity, and highlight the importance of IL-17 in intestinal contraction which may aid therapeutics to numerous diseases of the intestine., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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12. Reliability, Validity, and Factor Structure of the Internalized AIDS-Related Stigma Scale in Southern India.
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Chan BT, Pradeep A, Chandrasekaran E, Prasad L, Murugesan V, Kumarasamy N, Mayer KH, and Tsai AC
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- Acquired Immunodeficiency Syndrome epidemiology, Adult, Depression, Female, HIV Infections epidemiology, Humans, India epidemiology, Male, Middle Aged, Reproducibility of Results, Statistics, Nonparametric, Surveys and Questionnaires, Transgender Persons, Acquired Immunodeficiency Syndrome psychology, Behavior Rating Scale, HIV Infections psychology, Social Stigma
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We used data from 660 people living with HIV in southern India to evaluate the reliability, validity, and factor structure of the Internalized AIDS-Related Stigma Scale. Exploratory factor analysis revealed the presence of 2 factors: a 2-item factor related to disclosure concerns and a 4-item factor related to self-hatred. The self-hatred factor demonstrated acceptable internal consistency (Cronbach α = .80). As evidence of construct validity, both factors were correlated with depression symptom severity as measured by the Patient Health Questionnaire-9. Further study is needed to understand the correlates of these factors and their impact on the Indian HIV care continuum.
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- 2019
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13. Internalized HIV stigma, ART initiation and HIV-1 RNA suppression in South Africa: exploring avoidant coping as a longitudinal mediator.
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Earnshaw VA, Bogart LM, Laurenceau JP, Chan BT, Maughan-Brown BG, Dietrich JJ, Courtney I, Tshabalala G, Orrell C, Gray GE, Bangsberg DR, and Katz IT
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- Adult, Cross-Sectional Studies, Female, HIV Infections psychology, HIV Infections virology, Humans, Male, Middle Aged, Pregnancy, South Africa epidemiology, Adaptation, Psychological, Anti-HIV Agents therapeutic use, HIV Infections drug therapy, HIV-1 genetics, Social Stigma
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Introduction: Cross-sectional evidence suggests that internalized HIV stigma is associated with lower likelihoods of antiretroviral therapy (ART) initiation and HIV-1 RNA suppression among people living with HIV (PLWH). This study examined these associations with longitudinal data spanning the first nine months following HIV diagnosis and explored whether avoidant coping mediates these associations., Methods: Longitudinal data were collected from 398 South African PLWH recruited from testing centres in 2014 to 2015. Self-report data, including internalized stigma and avoidant coping (denying and distracting oneself from stressors), were collected one week and three months following HIV diagnosis. ART initiation at six months and HIV-1 RNA at nine months were extracted from the South Africa National Health Laboratory Service database. Two path analyses were estimated, one testing associations between internalized stigma, avoidant coping and ART initiation, and the other testing associations between internalized stigma, avoidant coping and HIV-1 RNA suppression., Results: Participants were 36 years old, on average, and 63% identified as female, 18% as Zulu and 65% as Xhosa. The two path models fit the data well (ART initiation outcome: X
2 (7) = 8.14, p = 0.32; root mean square error of approximation (RMSEA) = 0.02; comparative fit index (CFI) = 0.92; HIV-1 RNA suppression outcome: X2 (7) = 6.58, p = 0.47; RMSEA = 0.00; CFI = 1.00). In both models, internalized stigma one week after diagnosis was associated with avoidant coping at three months, controlling for avoidant coping at one week. In turn, avoidant coping at three months was associated with lower likelihood of ART initiation at six months in the first model and lower likelihood of HIV-1 RNA suppression at nine months in the second model. Significant indirect effects were observed between internalized stigma with ART non-initiation and unsuppressed HIV-1 RNA via the mediator of avoidant coping., Conclusions: Internalized stigma experienced soon after HIV diagnosis predicted lower likelihood of ART initiation and HIV-1 RNA suppression over the first year following HIV diagnosis. Avoidant coping played a role in these associations, suggesting that PLWH who internalize stigma engage in greater avoidant coping, which in turn worsens medication- and health-related outcomes. Interventions are needed to address internalized stigma and avoidant coping soon after HIV diagnosis to enhance treatment efforts during the first year after HIV diagnosis., (© 2018 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society.)- Published
- 2018
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14. HIV knowledge trends during an era of rapid antiretroviral therapy scale-up: an analysis of 33 sub-Saharan African countries.
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Chan BT and Tsai AC
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- Acquired Immunodeficiency Syndrome, Adolescent, Adult, Africa South of the Sahara, Female, HIV, Humans, Male, Surveys and Questionnaires, Young Adult, HIV Infections prevention & control, Health Knowledge, Attitudes, Practice
- Abstract
Introduction: Population-level improvements in knowledge about HIV may reduce the stigma attached to HIV and ensure maximal uptake of HIV prevention initiatives. The extent to which levels of HIV knowledge in the general population of sub-Saharan Africa have changed in the current era of antiretroviral therapy (ART) scale-up remains unknown., Methods: Data on HIV knowledge in the general population were drawn from the 2003 to 2015 Demographic and Health Surveys (DHS) and AIDS Indicator Surveys (AIS) of 33 countries in sub-Saharan Africa. The DHS/AIS contain five questions on HIV prevention and transmission that have been used by the Joint United Nations Programme on HIV/AIDS (UNAIDS) as a core indicator of HIV knowledge. We created a composite HIV knowledge variable equal to the number of correct responses to these five questions; a participant was considered to have comprehensive knowledge of HIV (yes/no) if he/she answered all five questions correctly. We fitted negative binomial regression models with cluster-correlated robust standard errors and country fixed effects, adjusted for socio-demographic variables, specifying HIV knowledge as the dependent variable and year as the explanatory variable. As an alternative parameterization, we also fitted a multivariable linear probability model with cluster-correlated robust standard errors and country fixed effects specifying comprehensive knowledge of HIV as the dependent variable., Results: A total of 791,186 women and 395,891 men participating in 75 DHS/AIS were included in the analyses. The mean HIV knowledge score was 3.7 among women and 3.9 among men (p < 0.001). Only 35% of women and 41% of men (p < 0.001) had a comprehensive knowledge of HIV. We estimated a modest but statistically significant positive association between year of DHS/AIS and HIV knowledge (adjusted b = 0.005; 95% confidence interval (CI), 0.001 to 0.009). Similarly, we estimated a statistically significant positive association between year of DHS/AIS and comprehensive knowledge of HIV (adjusted b = 0.011; 95% CI, 0.005 to 0.017), suggesting an approximately 1% relative increase per year in the percentage of the general population who possess a comprehensive knowledge of HIV., Conclusions: There have been minimal improvements over time in HIV knowledge across sub-Saharan Africa., (© 2018 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.)
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- 2018
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15. Personal contact with HIV-positive persons is associated with reduced HIV-related stigma: cross-sectional analysis of general population surveys from 26 countries in sub-Saharan Africa.
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Chan BT and Tsai AC
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- Adult, Africa South of the Sahara epidemiology, Cross-Sectional Studies, Female, HIV Infections epidemiology, Health Knowledge, Attitudes, Practice, Humans, Logistic Models, Male, Middle Aged, Psychological Distance, Surveys and Questionnaires, Young Adult, HIV Infections psychology, Social Stigma
- Abstract
Introduction: HIV-related stigma hampers treatment and prevention efforts worldwide. Effective interventions to counter HIV-related stigma are greatly needed. Although the "contact hypothesis" suggests that personal contact with persons living with HIV (PLHIV) may reduce stigmatizing attitudes in the general population, empirical evidence in support of this hypothesis is lacking. Our aim was to estimate the association between personal contact with PLHIV and HIV-related stigma among the general population of sub-Saharan Africa., Methods: Social distance and anticipated stigma were operationalized using standard HIV-related stigma questions contained in the Demographic and Health Surveys and AIDS Indicator Surveys of 26 African countries between 2003 and 2008. We fitted multivariable logistic regression models with country-level fixed effects, specifying social distance as the dependent variable and personal contact with PLHIV as the primary explanatory variable of interest., Results: We analyzed data from 206,717 women and 91,549 men living in 26 sub-Saharan African countries. We estimated a statistically significant negative association between personal contact with PLHIV and desires for social distance (adjusted odds ratio [AOR] = 0.80; p < 0.001; 95% Confidence Interval [CI], 0.73-0.88). In a sensitivity analysis, a similar finding was obtained with a model that used a community-level variable for personal contact with PLHIV (AOR = 0.92; p < 0.001; 95% CI, 0.89-0.95)., Conclusion: Personal contact with PLHIV was associated with reduced desires for social distance among the general population of sub-Saharan Africa. More contact interventions should be developed and tested to reduce the stigma of HIV., Competing Interests: The authors declare that they have no competing interests.
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- 2017
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16. Lack of interaction between ErbB2 and insulin receptor substrate signaling in breast cancer.
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Farabaugh SM, Chan BT, Cui X, Dearth RK, and Lee AV
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- Animals, Breast Neoplasms genetics, Breast Neoplasms pathology, Female, Humans, Insulin Receptor Substrate Proteins genetics, MCF-7 Cells, Male, Mice, Neoplasm Metastasis, Protein Binding, Receptor, ErbB-2 genetics, Signal Transduction, Breast Neoplasms metabolism, Insulin Receptor Substrate Proteins metabolism, Receptor, ErbB-2 metabolism
- Abstract
Background: ErbB2 Receptor Tyrosine Kinase 2 (ErbB2, HER2/Neu) is amplified in breast cancer and associated with poor prognosis. Growing evidence suggests interplay between ErbB2 and insulin-like growth factor (IGF) signaling. For example, ErbB2 inhibitors can block IGF-induced signaling while, conversely, IGF1R inhibitors can inhibit ErbB2 action. ErbB receptors can bind and phosphorylate insulin receptor substrates (IRS) and this may be critical for ErbB-mediated anti-estrogen resistance in breast cancer. Herein, we examined crosstalk between ErbB2 and IRSs using cancer cell lines and transgenic mouse models., Methods: MMTV-ErbB2 and MMTV-IRS2 transgenic mice were crossed to create hemizygous MMTV-ErbB2/MMTV-IRS2 bigenic mice. Signaling crosstalk between ErbB2 and IRSs was examined in vitro by knockdown or overexpression followed by western blot analysis for downstream signaling intermediates and growth assays., Results: A cross between MMTV-ErbB2 and MMTV-IRS2 mice demonstrated no enhancement of ErbB2 mediated mammary tumorigenesis or metastasis by elevated IRS2. Substantiating this, overexpression or knockdown of IRS1 or IRS2 in MMTV-ErbB2 mammary cancer cell lines had little effect upon ErbB2 signaling. Similar results were obtained in human mammary epithelial cells (MCF10A) and breast cancer cell lines., Conclusion: Despite previous evidence suggesting that ErbB receptors can bind and activate IRSs, our findings indicate that ErbB2 does not cooperate with the IRS pathway in these models to promote mammary tumorigenesis.
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- 2016
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17. Attitudes of Indian HIV Clinicians Toward Depression in People Living with HIV.
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Chan BT, Pradeep A, Mayer KH, and Kumarasamy N
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- Adult, Humans, India epidemiology, Middle Aged, Prejudice, Surveys and Questionnaires, Attitude of Health Personnel, Depression psychology, HIV Infections psychology, Health Knowledge, Attitudes, Practice
- Abstract
Background: Depression is highly prevalent in people living with HIV (PLHIV) and is associated with increased morbidity and mortality. In India, where access to mental health specialists is limited, little is known about the attitude of HIV clinicians toward depression in PLHIV., Methods: We administered a questionnaire to HIV clinicians attending the 2015 Chennai Antiretroviral Therapy Symposium that assessed respondents' level of agreement with 29 statements regarding the etiology, importance, and management of depression and whether they felt capable and willing to manage depression in PLHIV., Results: The 69 respondents were from 9 Indian states. Most respondents agreed that depression in PLHIV is a serious problem (91%) and is associated with poorer HIV-related outcomes (62%-81%). Although most respondents (76%) reported feeling comfortable discussing mental health problems with PLHIV, almost half (48%) admitted that lack of knowledge and training about mental health issues hindered the diagnosis and treatment of depression in PLHIV. With few exceptions, there were no significant differences in responses by gender, urban/rural practice location, or government versus private practice., Conclusions: Indian HIV clinicians believe that depression in PLHIV is important and are willing to manage depression in the HIV primary care setting. These findings suggest that HIV clinicians require further training to deliver evidence-based interventions to treat PLHIV with depression., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2016
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18. HIV stigma trends in the general population during antiretroviral treatment expansion: analysis of 31 countries in sub-Saharan Africa, 2003-2013.
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Chan BT and Tsai AC
- Subjects
- Africa South of the Sahara epidemiology, HIV Infections epidemiology, Health Knowledge, Attitudes, Practice, Humans, Medication Adherence statistics & numerical data, Patient Acceptance of Health Care statistics & numerical data, Psychological Distance, Stereotyping, Anti-HIV Agents therapeutic use, HIV Infections drug therapy, HIV Infections psychology, Medication Adherence psychology, Patient Acceptance of Health Care psychology, Risk-Taking, Social Stigma
- Abstract
Background: HIV-related stigma is associated with increased risk-taking behavior, reduced uptake of HIV testing, and decreased adherence to antiretroviral therapy (ART). Although ART scale-up may reduce HIV-related stigma, the extent to which levels of stigma in the general population have changed during the era of ART scale-up in sub-Saharan Africa is unknown., Methods: Social distance and anticipated stigma were operationalized using standard HIV-related stigma questions contained in the Demographic and Health Surveys and AIDS Indicator Surveys of 31 African countries between 2003 and 2013. We fitted multivariable linear regression models with cluster-correlated robust standard errors and country fixed effects, specifying social distance or anticipated stigma as the dependent variable and year as the primary explanatory variable of interest., Results: We estimated a statistically significant negative association between year and desires for social distance (b = -0.020; P < 0.001; 95% confidence interval: -0.026 to -0.015) but a statistically significant positive association between year and anticipated stigma (b = 0.023; P < 0.001; 95% confidence interval: 0.018 to 0.027). In analyses stratified by HIV prevalence above or below the sample median, declines in social distancing over time were more pronounced among countries with a higher HIV prevalence., Conclusions: Concomitant with ART scale-up in sub-Saharan Africa, anticipated stigma in the general population increased despite a decrease in social distancing toward people living with HIV. Although ART scale-up may help reduce social distancing toward people living with HIV, particularly in high-prevalence countries, other interventions targeting symbolic or instrumental concerns about HIV may be needed.
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- 2016
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19. HIV Treatment Scale-Up and HIV-Related Stigma in Sub-Saharan Africa: A Longitudinal Cross-Country Analysis.
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Chan BT, Tsai AC, and Siedner MJ
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- Adolescent, Adult, Africa South of the Sahara epidemiology, Antiviral Agents therapeutic use, Female, HIV Infections epidemiology, HIV Infections psychology, Humans, Longitudinal Studies, Male, Middle Aged, Patient Acceptance of Health Care psychology, Patient Acceptance of Health Care statistics & numerical data, Sex Factors, Surveys and Questionnaires, Young Adult, HIV Infections drug therapy, Stereotyping
- Abstract
Objectives: We estimated the association between antiretroviral therapy (ART) uptake and HIV-related stigma at the population level in sub-Saharan Africa., Methods: We examined trends in HIV-related stigma and ART coverage in sub-Saharan Africa during 2003 to 2013 using longitudinal, population-based data on ART coverage from the Joint United Nations Program on HIV/AIDS and on HIV-related stigma from the Demographic and Health Surveys and AIDS Indicator Surveys. We fitted 2 linear regression models with country fixed effects, with the percentage of men or women reporting HIV-related stigma as the dependent variable and the percentage of people living with HIV on ART as the explanatory variable., Results: Eighteen countries in sub-Saharan Africa were included in our analysis. For each 1% increase in ART coverage, we observed a statistically significant decrease in the percentage of women (b = -0.226; P = .007; 95% confidence interval [CI] = -0.383, -0.070) and men (b = -0.281; P = .009; 95% CI = -0.480, -0.082) in the general population reporting HIV-related stigma., Conclusions: An important benefit of ART scale-up may be the diminution of HIV-related stigma in the general population.
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- 2015
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20. Persistent HIV-related stigma in rural Uganda during a period of increasing HIV incidence despite treatment expansion.
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Chan BT, Weiser SD, Boum Y, Siedner MJ, Mocello AR, Haberer JE, Hunt PW, Martin JN, Mayer KH, Bangsberg DR, and Tsai AC
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- Adult, Cross-Sectional Studies, Data Collection, Female, Health Knowledge, Attitudes, Practice, Humans, Incidence, Male, Odds Ratio, Treatment Outcome, Uganda epidemiology, HIV Infections epidemiology, Rural Population statistics & numerical data, Social Stigma
- Abstract
Objective: Programme implementers have argued that the increasing availability of antiretroviral therapy (ART) will reduce the stigma of HIV. We analyzed data from Uganda to assess how HIV-related stigma has changed during a period of ART expansion., Design: Serial cross-sectional surveys., Methods: We analyzed data from the Uganda AIDS Rural Treatment Outcomes study during 2007-2012 to estimate trends in internalized stigma among people living with HIV (PLHIV) at the time of treatment initiation. We analyzed data from the Uganda Demographic and Health Surveys from 2006 to 2011 to estimate trends in stigmatizing attitudes and anticipated stigma in the general population. We fitted regression models adjusted for sociodemographic characteristics, with year of data collection as the primary explanatory variable., Results: We estimated an upward trend in internalized stigma among PLHIV presenting for treatment initiation [adjusted b = 0.18; 95% confidence interval (CI), 0.06-0.30]. In the general population, the odds of reporting anticipated stigma were greater in 2011 compared with 2006 [adjusted odds ratio (OR) = 1.80; 95% CI, 1.51-2.13], despite an apparent decline in stigmatizing attitudes (adjusted OR = 0.62; 95% CI, 0.52-0.74)., Conclusion: Internalized stigma has increased over time among PLHIV in the setting of worsening anticipated stigma in the general population. Further study is needed to better understand the reasons for increasing HIV-related stigma in Uganda and its impact on HIV prevention efforts.
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- 2015
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21. Sensitivity analysis of left ventricle with dilated cardiomyopathy in fluid structure simulation.
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Chan BT, Abu Osman NA, Lim E, Chee KH, Abdul Aziz YF, Abed AA, Lovell NH, and Dokos S
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- Cardiomyopathy, Dilated complications, Humans, Myocardial Infarction complications, Organ Size, Stress, Mechanical, Stroke Volume, Cardiomyopathy, Dilated pathology, Cardiomyopathy, Dilated physiopathology, Heart Ventricles pathology, Heart Ventricles physiopathology, Hydrodynamics, Models, Cardiovascular
- Abstract
Dilated cardiomyopathy (DCM) is the most common myocardial disease. It not only leads to systolic dysfunction but also diastolic deficiency. We sought to investigate the effect of idiopathic and ischemic DCM on the intraventricular fluid dynamics and myocardial wall mechanics using a 2D axisymmetrical fluid structure interaction model. In addition, we also studied the individual effect of parameters related to DCM, i.e. peak E-wave velocity, end systolic volume, wall compliance and sphericity index on several important fluid dynamics and myocardial wall mechanics variables during ventricular filling. Intraventricular fluid dynamics and myocardial wall deformation are significantly impaired under DCM conditions, being demonstrated by low vortex intensity, low flow propagation velocity, low intraventricular pressure difference (IVPD) and strain rates, and high-end diastolic pressure and wall stress. Our sensitivity analysis results showed that flow propagation velocity substantially decreases with an increase in wall stiffness, and is relatively independent of preload at low-peak E-wave velocity. Early IVPD is mainly affected by the rate of change of the early filling velocity and end systolic volume which changes the ventriculo:annular ratio. Regional strain rate, on the other hand, is significantly correlated with regional stiffness, and therefore forms a useful indicator for myocardial regional ischemia. The sensitivity analysis results enhance our understanding of the mechanisms leading to clinically observable changes in patients with DCM.
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- 2013
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22. Treatment of listeriosis in first trimester of pregnancy.
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Chan BT, Hohmann E, Barshak MB, and Pukkila-Worley R
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- Adult, Female, Humans, Injections, Intravenous, Listeria monocytogenes growth & development, Listeriosis microbiology, Pregnancy, Pregnancy Trimester, First, Treatment Outcome, Ampicillin therapeutic use, Anti-Bacterial Agents therapeutic use, Gentamicins therapeutic use, Listeria monocytogenes drug effects, Listeriosis drug therapy
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- 2013
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23. Peritoneal tuberculosis in a pregnant woman from Haiti, United States.
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Ard KL, Chan BT, Milner DA Jr, Farmer PE, and Koenig SP
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- Antitubercular Agents therapeutic use, Female, Haiti ethnology, Humans, Infant, Newborn, Live Birth, Male, Omentum microbiology, Omentum surgery, Peritonitis, Tuberculous microbiology, Peritonitis, Tuberculous therapy, Pregnancy, Pregnancy Complications, Infectious microbiology, Pregnancy Complications, Infectious therapy, Premature Birth microbiology, Treatment Outcome, Ultrasonography, United States, Peritonitis, Tuberculous diagnostic imaging, Pregnancy Complications, Infectious diagnostic imaging
- Published
- 2013
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24. Dietary exposure to inorganic arsenic of the Hong Kong population: results of the first Hong Kong total diet study.
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Wong WW, Chung SW, Chan BT, Ho YY, and Xiao Y
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- Adult, Aged, Aged, 80 and over, Arsenic analysis, Edible Grain, Female, Hong Kong, Humans, Male, Middle Aged, Oryza, Vegetables, Young Adult, Arsenic toxicity, Diet, Environmental Exposure analysis, Food Contamination analysis
- Abstract
Inorganic arsenic, a human carcinogen, can be found in the environment and food. In the first Hong Kong Total Diet Study, the dietary exposure of the Hong Kong people, including various age-gender subgroups, to inorganic arsenic was estimated for assessing the associated health risk. Food samples, which represented the Hong Kong people's diet, were collected and prepared "as consumed" for analysis. Concentrations of inorganic arsenic, as sum of arsenite (As(III)) and arsenate (As(V)) were determined in 600 composite samples by using inductively coupled plasma mass spectrometry. The dietary exposures were estimated by combining the analytical results with the local food consumption data of the adult population. The mean and 95th percentile of inorganic arsenic exposures of the Hong Kong people were 0.22 and 0.38μg/kg body weight (bw)/day, respectively. Among the 12 age-gender subgroups, the respective exposures ranged from 0.19 to 0.26μg/kg bw/day and from 0.33 to 0.46μg/kg bw/day. The main food category that contributed inorganic arsenic was "cereals and their products" (53.5% of the total exposure), particularly rice. Having considered the carcinogenic risk of inorganic arsenic to humans, it is suggested that efforts should be made to reduce the inorganic arsenic exposure of the Hong Kong population., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
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- 2013
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25. An analysis of Liberia's 2007 national health policy: lessons for health systems strengthening and chronic disease care in poor, post-conflict countries.
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Lee PT, Kruse GR, Chan BT, Massaquoi MB, Panjabi RR, Dahn BT, and Gwenigale WT
- Abstract
Background: Globally, chronic diseases are responsible for an enormous burden of deaths, disability, and economic loss, yet little is known about the optimal health sector response to chronic diseases in poor, post-conflict countries. Liberia's experience in strengthening health systems and health financing overall, and addressing HIV/AIDS and mental health in particular, provides a relevant case study for international stakeholders and policymakers in other poor, post-conflict countries seeking to understand and prioritize the global response to chronic diseases., Methods: We conducted a historical review of Liberia's post-conflict policies and their impact on general economic and health indicators, as well as on health systems strengthening and chronic disease care and treatment. Key sources included primary documents from Liberia's Ministry of Health and Social Welfare, published and gray literature, and personal communications from key stakeholders engaged in Liberia's Health Sector Reform. In this case study, we examine the early reconstruction of Liberia's health care system from the end of conflict in 2003 to the present time, highlight challenges and lessons learned from this initial experience, and describe future directions for health systems strengthening and chronic disease care and treatment in Liberia., Results: Six key lessons emerge from this analysis: (i) the 2007 National Health Policy's 'one size fits all' approach met aggregate planning targets but resulted in significant gaps and inefficiencies throughout the system; (ii) the innovative Health Sector Pool Fund proved to be an effective financing mechanism to recruit and align health actors with the 2007 National Health Policy; (iii) a substantial rural health delivery gap remains, but it could be bridged with a robust cadre of community health workers integrated into the primary health care system; (iv) effective strategies for HIV/AIDS care in other settings should be validated in Liberia and adapted for use in other chronic diseases; (v) mental health disorders are extremely prevalent in Liberia and should remain a top chronic disease priority; and (vi) better information systems and data management are needed at all levels of the health system., Conclusions: The way forward for chronic diseases in Liberia will require an increased emphasis on quality over quantity, better data management to inform rational health sector planning, corrective mechanisms to more efficiently align health infrastructure and personnel with existing needs, and innovative methods to improve long-term retention in care and bridge the rural health delivery gap.
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- 2011
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26. High IGF-IR activity in triple-negative breast cancer cell lines and tumorgrafts correlates with sensitivity to anti-IGF-IR therapy.
- Author
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Litzenburger BC, Creighton CJ, Tsimelzon A, Chan BT, Hilsenbeck SG, Wang T, Carboni JM, Gottardis MM, Huang F, Chang JC, Lewis MT, Rimawi MF, and Lee AV
- Subjects
- Animals, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Apoptosis drug effects, Breast Neoplasms genetics, Breast Neoplasms metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Cluster Analysis, Docetaxel, Gene Expression Profiling, Gene Expression Regulation, Neoplastic drug effects, Humans, Immunoblotting, Insulin-Like Growth Factor I metabolism, Insulin-Like Growth Factor I pharmacology, Mice, Mice, Inbred NOD, Mice, SCID, NIH 3T3 Cells, Pyrazoles administration & dosage, Receptor, ErbB-2 metabolism, Receptor, IGF Type 1 genetics, Receptor, IGF Type 1 metabolism, Receptor, Insulin antagonists & inhibitors, Receptor, Insulin genetics, Receptor, Insulin metabolism, Receptors, Estrogen metabolism, Receptors, Progesterone metabolism, Reverse Transcriptase Polymerase Chain Reaction, Taxoids administration & dosage, Taxoids pharmacology, Triazines administration & dosage, Breast Neoplasms drug therapy, Pyrazoles pharmacology, Receptor, IGF Type 1 antagonists & inhibitors, Triazines pharmacology, Xenograft Model Antitumor Assays
- Abstract
Purpose: We previously reported an insulin-like growth factor (IGF) gene expression signature, based on genes induced or repressed by IGF-I, which correlated with poor prognosis in breast cancer. We tested whether the IGF signature was affected by anti-IGF-I receptor (IGF-IR) inhibitors and whether the IGF signature correlated with response to a dual anti-IGF-IR/insulin receptor (InsR) inhibitor, BMS-754807., Experimental Design: An IGF gene expression signature was examined in human breast tumors and cell lines and changes were noted following treatment of cell lines or xenografts with anti-IGF-IR antibodies or tyrosine kinase inhibitors. Sensitivity of cells to BMS-754807 was correlated with levels of the IGF signature. Human primary tumorgrafts were analyzed for the IGF signature and IGF-IR levels and activity, and MC1 tumorgrafts were treated with BMS-754807 and chemotherapy., Results: The IGF gene expression signature was reversed in three different models (cancer cell lines or xenografts) treated with three different anti-IGF-IR therapies. The IGF signature was present in triple-negative breast cancers (TNBC) and TNBC cell lines, which were especially sensitive to BMS-754807, and sensitivity was significantly correlated to the expression of the IGF gene signature. The TNBC primary human tumorgraft MC1 showed high levels of both expression and activity of IGF-IR and IGF gene signature score. Treatment of MC1 with BMS-754807 showed growth inhibition and, in combination with docetaxel, tumor regression occurred until no tumor was palpable. Regression was associated with reduced proliferation, increased apoptosis, and mitotic catastrophe., Conclusions: These studies provide a clear biological rationale to test anti-IGF-IR/InsR therapy in combination with chemotherapy in patients with TNBC., (©2011 AACR.)
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- 2011
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27. The mechanical stress-activated serum-, glucocorticoid-regulated kinase 1 contributes to neointima formation in vein grafts.
- Author
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Cheng J, Wang Y, Ma Y, Chan BT, Yang M, Liang A, Zhang L, Li H, and Du J
- Subjects
- Animals, Carotid Artery Injuries enzymology, Carotid Artery Injuries pathology, Cyclin-Dependent Kinase Inhibitor p27 metabolism, Disease Models, Animal, Enzyme Activation, Gene Expression Profiling methods, Gene Expression Regulation, Enzymologic, Immediate-Early Proteins deficiency, Immediate-Early Proteins genetics, MAP Kinase Kinase 1 metabolism, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Muscle, Smooth, Vascular drug effects, Muscle, Smooth, Vascular pathology, Myocytes, Smooth Muscle drug effects, Myocytes, Smooth Muscle pathology, Oligonucleotide Array Sequence Analysis, Phosphatidylinositol 3-Kinases metabolism, Phosphorylation, Protein Kinase Inhibitors pharmacology, Protein Serine-Threonine Kinases deficiency, Protein Serine-Threonine Kinases genetics, Protein Transport, Proto-Oncogene Proteins c-akt metabolism, RNA, Messenger metabolism, Receptor, IGF Type 1 metabolism, Stress, Mechanical, Time Factors, Tissue Culture Techniques, Trans-Activators metabolism, Transcription Factors, Transfection, Tunica Intima drug effects, Tunica Intima pathology, Veins enzymology, Veins pathology, Veins transplantation, Cell Proliferation drug effects, Immediate-Early Proteins metabolism, Muscle, Smooth, Vascular enzymology, Myocytes, Smooth Muscle enzymology, Protein Serine-Threonine Kinases metabolism, Signal Transduction drug effects, Tunica Intima enzymology
- Abstract
Rationale: Mechanical stress plays an important role in proliferation of venous smooth muscle cells (SMCs) in neointima, a process of formation that contributes to failure of vein grafts. However, it is unknown what intracellular growth signal leads to proliferation of venous SMCs., Objective: The objective of this study is to identify mechanisms of mechanical stretch on neointima formation., Methods and Results: By a microarray analysis, we found that mechanical cyclic stretch (15% elongation) stimulated the transcription of SGK-1 (serum-, glucocorticoid-regulated kinase-1). Mechanical stretch-induced SGK-1 mRNA expression was blocked by actinomycin D. The mechanism for the SGK-1 expression involved MEK1 but not p38 or JNK signaling pathway. SGK-1 activation in response to stretch is blocked by insulin-like growth factor (IGF)-1 receptor inhibitor and mammalian target of rapamycin complex (mTORC)2 inhibitor (Ku-0063794) but not mTORC1 inhibitor (rapamycin). Mechanical stretch-induced bromodeoxyuridine incorporation was reduced by 83.5% in venous SMCs isolated from SGK-1 knockout mice. In contrast, inhibition of Akt, another downstream signal of PI3K resulted in only partial inhibition of mechanical stretch-induced proliferation of venous SMCs. Mechanical stretch also induced phosphorylation and nuclear exportation of p27(kip1), whereas knockout of SGK-1 attenuated this effect of mechanical stretch on p27(kip1). In vivo, we found that placement of a vein graft into artery increased SGK-1 expression. Knockout of SGK-1 effectively prevented neointima formation in vein graft. There is significant lower level of p27(kip1) located in the nucleus of neointima cells in SGK-1 knockout mice compared with that of wild-type vein graft. In addition, we also found that wire injury of artery or growth factors in vitro increased expression of SGK-1., Conclusions: These results suggest that SGK-1 is an injury-responsive kinase that could mediate mechanical stretch-induced proliferation of vascular cells in vein graft, leading to neointima formation.
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- 2010
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28. Examining asthma quality of care using a population-based approach.
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Klomp H, Lawson JA, Cockcroft DW, Chan BT, Cascagnette P, Gander L, and Jorgenson D
- Subjects
- Administration, Inhalation, Adolescent, Adrenal Cortex Hormones therapeutic use, Adrenergic beta-Agonists therapeutic use, Adult, Age Distribution, Anti-Asthmatic Agents therapeutic use, Asthma epidemiology, Canada epidemiology, Child, Child, Preschool, Cross-Sectional Studies, Databases, Factual, Drug Prescriptions statistics & numerical data, Female, Hospitalization statistics & numerical data, Humans, Male, Middle Aged, Prevalence, Retrospective Studies, Sex Distribution, Asthma drug therapy, Quality of Health Care
- Abstract
Background: Asthma accounts for considerable burden on health care, but in most cases, asthma can be controlled. Quality-of-care indicators would aid in monitoring asthma management. We describe the quality of asthma care using a set of proposed quality indicators., Methods: We performed a retrospective cross-sectional study using health databases in Saskatchewan, a Canadian province with a population of about 1 million people. We assessed 6 quality-of-care indicators among people with asthma: admission to hospital because of asthma; poor asthma control (high use of short-acting beta-agonists, admission to hospital because of asthma or death due to asthma); no inhaled corticosteroid use among patients with poor control; at least moderate inhaled corticosteroid use among patients with poor control; high inhaled corticosteroid use and use of another preventer medication among patients with poor control; and any main preventer use among patients with poor control. We calculated crude and adjusted rates with 95% confidence intervals. We tested for differences using the chi2 test for proportions and generalized linear modelling techniques., Results: In 2002/03, there were 24 616 people aged 5-54 years with asthma in Saskatchewan, representing a prevalence of 3.8%. Poor symptom control was observed in 18% of patients with asthma. Among those with poor control, 37% were not dispensed any inhaled corticosteroids, and 40% received potentially inadequate doses. Among those with poor control who were dispensed high doses of inhaled corticosteroids, 26% also used another preventer medication. Hospital admissions because of asthma were highest among those aged 6-9 years and females aged 20-44 years. Males and those in adult age groups (predominantly 20-44 years) had worse quality of care for 4 indicators examined., Interpretation: Suboptimal asthma management would be improved through increased use of inhaled corticosteroids and preventer medications, and reduced reliance on short-acting beta-agonist medications as recommended by consensus guidelines.
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- 2008
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29. Graduates of northern Ontario family medicine residency programs practise where they train.
- Author
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Heng D, Pong RW, Chan BT, Degani N, Crichton T, Goertzen J, McCready W, and Rourke J
- Subjects
- Adult, Female, Humans, Male, Ontario, Workforce, Family Practice, Internship and Residency, Rural Health Services
- Abstract
Objective: To examine where graduates of the Northeastern Ontario Family Medicine (NOFM) residency program in Sudbury and the Family Medicine North (FMN) program in Thunder Bay practise after graduation, using cross-sectional and longitudinal analyses., Methods: Data from the Scott's Medical Database were examined. All physicians who graduated from NOFM and FMN between 1993 and 2002 were included in this analysis. Differences in the location of first practice between NOFM and FMN graduates were tested using chi-squared tests. Logistic regression analyses were used to examine the impact of the training program on a physician's first, as well as continuing, practice location., Results: Between 1993 and 2002, FMN graduates were 4.56 times more likely (95% confidence interval [CI] 2.34-8.90) to practise in rural areas, compared with NOFM graduates, but NOFM graduates were 2.50 times more likely than FMN graduates (95% CI 1.35-4.76) to practise in northern Ontario. There was no statistically significant difference between the graduates of the 2 programs in the likelihood of working in either northern Ontario or a rural area. About two-thirds (67.5%) of all person-years of medical practice provided by NOFM and FMN graduates took place in northern Ontario or rural areas outside the north., Conclusion: NOFM and FMN have been successful in producing family physicians to work in northern Ontario and rural areas. Results from this study add to the growing evidence from Canada and abroad that rural or northern medical education and training increases the likelihood that the graduates will practise in rural or northern communities.
- Published
- 2007
30. Big cities and bright lights: rural- and northern-trained physicians in urban practice.
- Author
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Pong RW, Chan BT, Crichton T, Goertzen J, McCready W, and Rourke J
- Subjects
- Female, Humans, Male, Ontario, Workforce, Family Practice education, Urban Health Services
- Abstract
Introduction: Rural medical education is increasing in popularity in Canada. This study examines why some family physicians who completed their residency training in northern Ontario decided to practise in urban centres., Methods: We used a qualitative research method. We interviewed 14 graduates of the Family Medicine North program and the Northeastern Ontario Family Medicine program. The interview transcripts were content-analyzed., Results: There were different pathways leading to urban practice. While some pathways were straightforward, others were more complicated. Most participants offered multiple reasons for choosing to work in urban areas, suggesting that the decision-making processes could be quite complex. Family and personal factors were most frequently mentioned as reasons for choosing the urban option. The needs of the spouse and the children were especially important. Most of the participants had no plans to return to rural medical practice, but even these physicians retained some vestiges of rural practice., Conclusion: Most Canadian medical schools now offer some rural medical training opportunities. The findings of this study provide some useful insights that could help medical educators and decision-makers know what to expect and understand how practice location decisions are made by doctors.
- Published
- 2007
31. Duration of rural training during residency: rural family physicians prefer 6 months.
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Chan BT, Degani N, Crichton T, Pong RW, Rourke JT, Goertzen J, and McCready B
- Subjects
- Adult, Attitude of Health Personnel, Canada, Data Collection, Female, Humans, Male, Physicians, Time Factors, Family Practice education, Internship and Residency statistics & numerical data, Rural Health Services
- Abstract
Objective: To determine whether rural family physicians thought they had received enough months of rural exposure during family medicine residency, how many months of rural exposure those who were satisfied with their training had had, and how many months of rural exposure those who were not satisfied with their training wanted., Design: Mailed survey., Setting: Rural Canada., Participants: Rural family physicians who had graduated between 1991 and 2000 from a Canadian medical school., Main Outcome Measures: Respondents' opinions about whether their exposure to rural medicine during training had been adequate., Results: Response rate was 59% (382/651). After excluding physicians who had not had Canadian family medicine residency training, 348 physicians remained, and of those, 58% thought they had had adequate rural exposure during residency. Median duration of rural training among those who thought they had had enough rural exposure was 6 months; median duration of rural exposure among those who thought they had not had enough was 2 months. Median duration of rural exposure desired by those who thought they had not had enough rural training was 6 months. Some physicians wanted much more than 6 months of rural training; for example, one quarter of those satisfied with their rural training had had 10 or more months of rural rotations. Fewer than 1% of respondents thought they had received too much rural training. There was no significant difference in number of months of rural training preferred by men and women (P = .94). One third of respondents had graduated from rural-focused family practice residency programs. Rural program graduates were more likely than non-rural program graduates to report that the duration of their rural training was adequate (84% vs 46%, P < .0001) and to report more mean months of rural exposure (8.9 vs 3.4; P < .0001)., Conclusion: Typical rural family physicians prefer to have 6 months of rural exposure during residency. This finding is consistent with the recommendation of a College of Family Physicians of Canada committee that rural family medicine training programs offer at least 6 months of rural rotations. Almost half of rural family physicians wished they had had more rural training. Both rural-focused and non-rural-focused programs should consider providing opportunities for pursuing elective rotations in rural areas in addition to mandatory rotations if they want to respond to these preferences for training.
- Published
- 2006
32. Factors influencing family physicians to enter rural practice: does rural or urban background make a difference?
- Author
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Chan BT, Degani N, Crichton T, Pong RW, Rourke JT, Goertzen J, and McCready B
- Subjects
- Adult, Decision Making, Female, Health Care Surveys, Humans, Male, Workforce, Family Practice, Rural Health Services, Rural Population, Urban Population
- Abstract
Objective: To examine where rural physicians grew up, when during their training they became interested in rural medicine, factors influencing their decision to practise rural medicine, and differences in these measures according to rural or urban upbringing., Design: Mailed survey., Setting: Rural Canada., Participants: Rural family physicians who graduated between 1991 and 2000 from a Canadian medical school., Main Outcome Measures: Backgrounds of recently graduated rural physicians, when physicians first became interested in rural practice during training, and most influential factors in decisions to practise rural medicine., Results: Response rate was 59% (382/651). About 33% of rural physicians grew up in communities of less than 10 000 people, 44% in cities of 10 000 to 499 999 people, and 23% in cities of more than 500 000 people. Physicians raised in rural areas were more likely than those raised in urban areas to have some interest in rural family practice at the start and end of medical school (90% vs 67% at the start, 98% vs 91% at the end, respectively, P < .0001). Physicians raised in urban areas were more likely to state that rural medical training was the most influential factor in their choice of rural practice (19% vs 9%, P = .015). Other factors cited as influential were the challenge of rural practice (24% for both urban and rural upbringing), rural lifestyle (14% for urban and 18% for rural upbringing) and, for physicians raised in rural areas, having grown up or spent time in a rural area (27% for rural and 4.1% for urban upbringing, P < .001). Financial incentives were least frequently cited as the most influential factor (7.5% for urban and 4.9% for rural upbringing, P = .35)., Conclusion: Although other studies have suggested that physicians with a rural upbringing are more likely to practise rural medicine and policy makers might still wish to target students raised in rural areas as candidates for rural medicine, this study shows that physicians raised in urban areas remain the main source of human resources for rural communities. They account for two thirds of new physicians in rural areas. Education in rural medicine during medical training has a stronger influence on physicians raised in urban areas than on physicians raised in rural areas. Undergraduate and postgraduate training periods, therefore, offer an important opportunity for recruiting physicians raised in urban areas to rural practice.
- Published
- 2005
33. Canadian rural family medicine training programs: growth and variation in recruitment.
- Author
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Krupa LK and Chan BT
- Subjects
- Canada, Data Collection, Humans, Interprofessional Relations, Personnel Selection, Physicians supply & distribution, Workforce, Family Practice education, Internship and Residency trends, Rural Health Services
- Abstract
Objective: To document the proliferation of rural family medicine residency programs and to note differences in design as they affect rural recruitment., Design: Descriptive study using semistructured telephone interviews., Setting: All family medicine residency programs in Canada in 2002., Participants: Directors of Canadian family medicine residency programs., Main Outcome Measures: Number of rural training programs and positions; months of rural exposure, degree of remoteness, and specialist support of rural communities within rural training programs., Results: The number of rural training programs rose from one in 1973 to 12 in 2002. Most medical schools now offer dedicated rural training streams. From 1989 to 2002, the number of rural residency positions quadrupled from 36 to 144; large jumps in capacity occurred from 1989 to 1991 and then from 1999 to 2001. Rural positions now represent 20% of all family medicine residency positions. Among rural programs, minimum rural exposure ranged from 4 to 12 months, and the median distance between rural training communities and referral sites ranged from 50 to 440 km (median 187 km). Rotations in communities with no hospital were mandatory in five of 12 rural programs, optional in five, and unavailable in two. The proportion of training communities used by rural programs that had family physicians only (ie, no immediate specialty backup) ranged from 0 to 78% (mean 44%). Most training communities (78%) used by rural programs had fewer than 10 000 residents. Four of 12 rural programs offered various specialty medicine rotations in small communities., Conclusion: Rural residency programs have proliferated in Canada. The percentage of residency positions that are rural now equals the proportion of the general population in Canada living in rural areas. National guidelines for rural programs recommend at least 6 months of rural rotations and at least some training in communities without hospitals. Major variations among programs exist, and most program designs differ from designs recommended in national guidelines in at least one aspect.
- Published
- 2005
34. Time trends and geographic disparities in acute complications of diabetes in Ontario, Canada.
- Author
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Booth GL, Hux JE, Fang J, and Chan BT
- Subjects
- Acute Disease, Diabetes Complications therapy, Health Services Accessibility statistics & numerical data, Health Services Accessibility trends, Humans, Hyperglycemia epidemiology, Hyperglycemia therapy, Hypoglycemia epidemiology, Hypoglycemia therapy, Indians, North American statistics & numerical data, Ontario epidemiology, Predictive Value of Tests, Registries, Risk Factors, Rural Population statistics & numerical data, Time Factors, Urban Population statistics & numerical data, Diabetes Complications epidemiology, Emergency Medical Services statistics & numerical data, Emergency Medical Services trends, Hospitalization statistics & numerical data, Hospitalization trends
- Abstract
Objective: This study examines whether acute diabetes complication rates have fallen in recent years and whether geographic factors influence these trends., Research Design and Methods: A population-based time-trend analysis of acute complications of diabetes was conducted using linked administrative and census data from Ontario, Canada. The study population included all adults identified through a province-wide electronic diabetes registry between 1994 and 1999 (n = 577,659). The primary outcome was hospitalizations for hyper- and hypoglycemia and emergency department visits for diabetes., Results: Between 1994 and 1999, rates of hospitalization for hyper- and hypoglycemic emergencies decreased by 32.5 and 76.9%, respectively; emergency department visits for diabetes fell by 23.9%. On multivariate analysis, fiscal year was an independent predictor of acute diabetes complications, with individuals in our cohort experiencing a decline in risk of approximately 6% per year for either being hospitalized with hyper- or hypoglycemia or requiring an emergency department visit for diabetes. After accounting for variation in physician service use, diabetic individuals living in rural areas or Aboriginal communities were nearly twice as likely to have an acute complication, whereas those residing in remote areas of the province were nearly three times as likely to experience an event., Conclusions: Although our findings suggest an overall improvement in diabetes care in Ontario, certain subgroups of the population continue to experience higher rates of complications that are potentially preventable through good ambulatory care. Measures to improve access to timely and effective outpatient care may further reduce rates of acute complications among the diabetic population.
- Published
- 2005
- Full Text
- View/download PDF
35. Patient, physician, and community factors affecting referrals to specialists in Ontario, Canada: a population-based, multi-level modelling approach.
- Author
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Chan BT and Austin PC
- Subjects
- Adolescent, Adult, Age Distribution, Aged, Catchment Area, Health statistics & numerical data, Child, Child, Preschool, Cross-Sectional Studies, Female, Humans, Infant, Male, Middle Aged, Models, Statistical, Multivariate Analysis, Ontario epidemiology, Poisson Distribution, Sex Distribution, Social Class, Universal Health Insurance, Family Practice statistics & numerical data, Medicine statistics & numerical data, Practice Patterns, Physicians' statistics & numerical data, Referral and Consultation statistics & numerical data, Residence Characteristics statistics & numerical data, Specialization
- Abstract
Question Addressed: This population-based study examines the factors affecting referrals by primary care physicians (PCPs) to specialists., Materials and Methods: Multilevel Poisson models were used to test the impact of patient, physician and community-level variables on the referral rate (the number of office-based specialist referrals per patient by the patient's customary PCP in fiscal year 1997/98). Patients from each of 6972 PCPs with sufficient data in Ontario were examined., Results: The average patient had 0.56 referrals per year (range 0-61). Referrals were higher at ages 1 and 77 to 78, and among women of childbearing age. Chronic disease variables were strongly correlated with referral rates. Patients in poor neighborhoods had more referrals, because they had more chronic diseases. After controlling for disease, individuals in the top 9% wealthiest neighborhoods had 4% more referrals. Female physicians made 8% more referrals than men. Older physicians referred more because they saw older patients; after controlling for patient age, physician age had no effect. Referrals were 14% higher in cities with medical schools compared with other cities and 12% lower in small towns. However, local specialist supply was unrelated to referral rates., Conclusion: This study improves our understanding of the impact of physician gender and age on referrals. It suggests that community type, not specialist supply, predicts variations in referrals. Lastly, it identifies preferential access to specialists among high-income earners, even within Canada's universal health insurance system. However, this effect is modest, suggesting that the system does provide reasonably equitable access to referrals.
- Published
- 2003
- Full Text
- View/download PDF
36. Geography and service supply do not explain socioeconomic gradients in angiography use after acute myocardial infarction.
- Author
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Alter DA, Naylor CD, Austin PC, Chan BT, and Tu JV
- Subjects
- Cardiac Care Facilities, Cardiology Service, Hospital, Cohort Studies, Confidence Intervals, Coronary Angiography economics, Cost Control, Cost-Benefit Analysis, Female, Follow-Up Studies, Humans, Logistic Models, Male, Multivariate Analysis, Odds Ratio, Ontario, Professional Practice Location, Registries, Coronary Angiography statistics & numerical data, Health Services Accessibility, Myocardial Infarction diagnostic imaging, Practice Patterns, Physicians' statistics & numerical data, Social Class
- Abstract
Background: Socioeconomic status appears to be an important predictor of coronary angiography use after acute myocardial infarction. One potential explanation for this is that patients with lower socioeconomic status live in neighbourhoods near nonteaching hospitals that have no catheterization capacity, few specialists and lower volumes of patients with acute myocardial infarction. This study was conducted to determine whether the impact of socioeconomic status on angiography use would be lessened by considering variations in the supply of services., Methods: We examined payment claims for physician services, hospital discharge abstracts and vital status data for 47 036 patients with acute myocardial infarction admitted to hospitals in Ontario between April 1994 and March 1997. Neighbourhood income of each patient was obtained from Canada's 1996 census. Using multivariate hierarchical logistic regression and adjusting for baseline patient and physician factors, we examined the interaction among hospital and regional characteristics, socioeconomic status and angiography use in the first 90 days after admission to hospital for acute myocardial infarction., Results: Within each hospital and geographic subgroup, crude rates of angiography rose progressively with increases in neighbourhood income. After adjusting for sociodemographic, clinical and physician characteristics, hospitals with on-site angiography capacity (adjusted odds ratio [OR] 1.88, 95% confidence interval [CI] 1.52-2.33), those with university affiliations (adjusted OR 1.60, 95% CI 1.27-2.01) and those closest to tertiary institutions (adjusted OR 1.57, 95% CI 1.32-1.87) were all associated with higher 90-day angiography use after acute myocardial infarction. However, the relative impact of socioeconomic status on 90-day angiography use was similar whether or not hospitals had on-site procedural capacity (interaction term p = 0.68), had university affiliations (interaction term p = 0.99), were near tertiary facilities (interaction term p = 0.67) or were in rural or urban regions (interaction term p = 0.90)., Interpretation: Socioeconomic status was as important a predictor of angiography use in hospitals with ready access to cardiac catheterization facilities as it was in those without. The socioeconomic gradient in the use of angiography after acute myocardial infarction cannot be explained by the distribution of specialists or tertiary hospitals.
- Published
- 2003
37. Do family physicians with emergency medicine certification actually practise family medicine?
- Author
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Chan BT
- Subjects
- Adult, Canada, Career Choice, Emergency Medicine education, Emergency Service, Hospital statistics & numerical data, Family Practice education, Female, Humans, Male, Certification, Emergency Medicine statistics & numerical data, Family Practice statistics & numerical data
- Published
- 2002
38. Frequent users of emergency departments. Do they also use family physicians' services?
- Author
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Chan BT and Ovens HJ
- Subjects
- Adult, Aged, Communication, Cross-Sectional Studies, Female, Health Care Surveys, Humans, Male, Middle Aged, Ontario, Referral and Consultation, Emergency Service, Hospital statistics & numerical data, Primary Health Care statistics & numerical data
- Abstract
Objective: To determine whether frequent users of emergency department (ED) services use more or fewer primary care services than other ED patients., Design: Population-based, observational, cross-sectional study., Setting: Province of Ontario in 1997-1998., Participants: Frequent users of EDs, defined as people with at least 12 ED physician assessments yearly, were compared with those with one to 11 assessments yearly., Main Outcome Measures: Number of general practitioner and family physician (GP/FP) office visits and number of GP/FPs visited; diagnoses made during office visits; referrals by GP/FPs to specialists., Results: Three quarters of frequent users of EDs visited GP/FPs at least six times yearly, and more than half visited at least 12 times yearly. Although frequent users of EDs saw many GP/FPs (4.2 vs 1.6 in the control group, P < .001), they received, on average, 73% of their primary care from the GP/FPs whom they saw most frequently. Frequent users of EDs also had more referrals to specialists (4.0 vs 1.0). Frequent users of EDs were more likely to live in low socioeconomic neighbourhoods and to be diagnosed with psychosocial conditions (24.1% vs 11.1%)., Conclusion: Most frequent users of EDs have periodic contact with primary care physicians. Communication and coordination of care between EDs and primary care settings could be easier than anticipated, because in most cases, frequent users of EDs seek most of their care from one main ED and one primary care physician.
- Published
- 2002
39. The declining comprehensiveness of primary care.
- Author
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Chan BT
- Subjects
- Adult, Aged, Databases, Factual, Female, Humans, Male, Middle Aged, Ontario, Rural Population, Urban Population, Comprehensive Health Care statistics & numerical data, Comprehensive Health Care trends, Family Practice trends, Practice Patterns, Physicians' statistics & numerical data
- Abstract
Background: Recent studies suggest that comprehensiveness of primary care has declined steadily over the past decade. This study tracks the participation rates of general practitioners and family physicians in 6 nonoffice settings across Ontario and examines among which types of physicians this decline in comprehensiveness has occurred., Methods: Billing (claims) records were used to determine the proportions of fee-for-service general practitioners and family physicians who provided emergency, inpatient, nursing home, house call, anesthesia or obstetrical services from 1989/90 to 1999/2000. "Office-only" physicians were those who worked in none of these nonoffice settings. The relation of various physician characteristics to comprehensiveness of care was tested with multivariate analysis for 1999/2000., Results: The proportion of "office-only" general practitioners and family physicians rose from 14% in 1989/90 to 24% in 1999/2000 (p < 0.001). Significant increases in this proportion were noted among general practitioners and family physicians of all ages, both sexes and all practice locations. In 1999/2000, recent graduates (who had completed medical school within the past 7 years) had higher participation rates for emergency medicine (40% v. 5% for physicians aged 65 years and older); female physicians had higher participation rates for obstetrics (16% v. 11% for males); and older physicians had higher participation rates for nursing home visits and house calls (20% and 57% respectively v. 11% and 37% for recent graduates). However, "office-only" physicians were more likely to be female (odds ratio [OR] 2.65, 95% confidence interval [CI] 2.37-2.96), recent graduates (OR 1.35, 95% CI 1.15-1.60), aged 65 years and older (OR 1.45, 95% CI 1.20-1.75) or practising in a city with a medical school (OR 2.30, 95% CI 2.06-2.56) and were less likely to be rural physicians (OR 0.31, 95% CI 0.24-0.41) or certified in family medicine (OR 0.58, 95% CI 0.52-0.66)., Interpretation: There has been a decline in the provision of comprehensive care by general practitioners and family physicians in Ontario. The decline is evident across all age groups and for both male and female physicians. It is also evident in rural areas and in cities with and without medical schools.
- Published
- 2002
40. Heavy users of emergency services: a population-based review.
- Author
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Ovens HJ and Chan BT
- Subjects
- Female, Humans, Male, Ontario, Utilization Review methods, Emergency Service, Hospital statistics & numerical data
- Published
- 2001
41. Asthma in children: Management practices among paediatricians and family physicians.
- Author
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Mitchell I, Choi BC, McRae L, and Chan BT
- Abstract
Objective: To ascertain the variation in asthma management practices among paediatricians and family physicians to determine how to improve care., Design: Questionnaire study of paediatricians and family physicians that focused on the use of beta(2)-agonists, inhaled corticosteroids, patient asthma education, quantitative measurements of airflow and diagnostic investigations for asthma. Case scenarios were used in the questionnaire., Results: The response rate was 66% (415 of 632) among paediatricians and 42% (1156 of 2750) among family physicians. In general, both groups followed consensus guidelines. There were some differences in management practices among paediatricians and family physicians. Paediatricians were more likely to develop an action plan and less likely to use xanthines or inhaled anticholinergic agents. However, family physicians were more likely to use spirometry or home peak expiratory flow rates to make a diagnosis of asthma., Conclusion: Family physicians and paediatricians require a different focus on educational interventions to improve the care of children with asthma.
- Published
- 2001
- Full Text
- View/download PDF
42. Physician asthma management practices in Canada.
- Author
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Jin R, Choi BC, Chan BT, McRae L, Li F, Cicutto L, Boulet LP, Mitchell I, Beveridge R, and Leith E
- Subjects
- Asthma diagnosis, Canada, Humans, Patient Education as Topic, Practice Guidelines as Topic, Asthma therapy, Health Care Surveys, Practice Patterns, Physicians'
- Abstract
Objectives: To establish national baseline information on asthma management practices of physicians, to compare the reported practices with the Canadian Consensus recommendations and to identify results potentially useful for interventions that improve physician asthma management practices., Design: National, stratified cross-sectional survey., Settings: The 10 provinces and two territories of Canada, from 1996 to 1997., Participants: Questionnaires were sent to 4489 physicians stratified by province/territory and specialty group (family/general practice, respirology, internal medicine, pediatrics and allergy/immunology); 2605 responses were received., Outcome Measures: Methods for the diagnosis, treatment, education and follow-up of patients with asthma ('asthma management practices')., Results: Significant variations existed among the five specialty groups in asthma management practices. A low use of objective measures of airflow limitation to assist with diagnosis was found among some respondents (mostly family physicians). Up to 40% of physicians regarded the daily fixed dosing (three or four times a day) of inhaled, short acting beta2-agonist as 'first-line therapy' for moderate to severe asthma. A minority of physicians reported using written action plans for patients or referring them to other health professionals for asthma education. Insufficient time during appointments and a perceived lack of appropriate educational materials were frequently cited as reasons for not providing asthma education. The perceived knowledge of the Canadian Consensus recommendations varied among physicians but was lowest among nonspecialists., Conclusions: The survey showed variations in certain aspects of the management of asthma by physicians. The findings will help to target specific areas for future physician education programs and other behavioural change strategies.
- Published
- 2000
- Full Text
- View/download PDF
43. Patterns of use of the bone mineral density test in Ontario, 1992-1998.
- Author
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Jaglal SB, McIsaac WJ, Hawker G, Jaakkimainen L, Cadarette SM, and Chan BT
- Subjects
- Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Fractures, Spontaneous prevention & control, Humans, Incidence, Male, Middle Aged, Ontario epidemiology, Osteoporosis prevention & control, Osteoporosis, Postmenopausal prevention & control, Absorptiometry, Photon statistics & numerical data, Fractures, Spontaneous epidemiology, Mass Screening statistics & numerical data, Osteoporosis epidemiology, Osteoporosis, Postmenopausal epidemiology
- Abstract
Background: There is ongoing controversy about who should be referred for bone mineral density (BMD) testing to estimate fracture risk and diagnose osteoporosis. The purpose of this study was to examine patterns of use of BMD testing in Ontario between 1992 and 1998., Methods: All physician claims from the Ontario Health Insurance Plan (OHIP) claims database for BMD testing between Jan. 1, 1992, and Dec. 31, 1998, were categorized by age and sex of the patient and the specialty of the physician who ordered the test. Time trends and regional rate variation analyses were also performed. To examine the prevalence of repeat testing, an inception cohort of women who had a BMD test in 1996 was followed for 2 years from the date of first test., Results: From 1992 to 1998 the number of BMD tests performed per year in women increased from 34,402 to 230,936 and in men from 2,162 to 13,579. In 1998 most tests were being ordered by family physicians (80.2% in 1998 v. 52.1% in 1992). Approximately 1 in 7 women aged 55-69 years had BMD tests done in 1998. Within a 2-year period 29.3% of these women had the test repeated; the mean time between tests was 16 months. Regional rate variation analyses of BMD tests performed in 1996-1998 indicated a 235-fold variation in BMD test rates across counties in Ontario, with a range from 0.2 to 47.1 per 1000 women in the population., Interpretation: The number of BMD tests performed each year in Ontario is increasing rapidly. However, the significant variation between rates of testing in different regions indicates that the diffusion of this technology may not be taking place according to population need.
- Published
- 2000
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