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1,797 results on '"Wells, George A"'

1. Is it time to start moving soil microbial fuel cell research out of the lab and into the field?

Author

Taylor, Stephen, Jaliff, Laura, Wells, George, and Josephson, Colleen

Subjects
Biological Sciences, Industrial Biotechnology, Affordable and Clean Energy, Microbial fuel cell, Soil, Soil microbial fuel cell, Environmental Sciences
Abstract

Soil microbial fuel cells (SMFCs) function as bioelectrochemical energy harvesters that convert electrons stored in soil organic matter into useful electrical energy. Broadly, an SMFC comprises three essential components: an anode buried in the soil (the negative terminal), a colony of exoelectrogenic microorganisms residing on this anode, and a cathode (the positive terminal). As the exoelectrogens respire, they release electrons to the anode, which acts as an external receptor. These released electrons then flow through a load (e.g. a resistor), connecting the anode and cathode. Though minuscule, the electrical power produced by SMFCs has a number of potential applications such as sustaining low-power embedded electronics, pollutant remediation, or as a bio-sensing proxy for soil qualities and microbial activity. This discussion aims to emphasize the potential of SMFCs in addressing real-world environmental issues and to generate interest in the larger scientific community for broad interdisciplinary research efforts, particularly in field deployments.

Published
2024

3. The Future of Clean Computing May Be Dirty

Author

Josephson, Colleen, Shuai, Weitao, Marcano, Gabriel, Pannuto, Pat, Hester, Josiah, and Wells, George

Subjects
Engineering, Information and Computing Sciences, Data Management and Data Science, Distributed Computing and Systems Software, Human-Centred Computing, Affordable and Clean Energy, Communications engineering, Distributed computing and systems software
Abstract

The emergence of the Internet of Things and pervasive sensor networks have generated a surge of research in energy scavenging techniques. We know well that harvesting RF, solar, or kinetic energy enables the creation of battery-free devices that can be used where frequent battery changes or dedicated power lines are impractical. One unusual yet ubiquitous source of power is soil (earth itself) - or more accurately, bacterial communities in soil. Microbial fuel cells (MFCs) are electrochemical cells that harness the activities of microbes that naturally occur in soil, wetlands, and wastewater. MFCs have been a topic of research in environmental engineering and microbiology for decades, but are a relatively new topic in electronics design and research. Most low-power electronics have traditionally opted for batteries, RF energy, or solar cells. This is changing, however, as the limitations and costs of these energy sources hamper our ability to deploy useful systems that last for decades in challenging environments. If large-scale, long-term applications like underground infrastructure monitoring, smart farming, and sensing for conservation are to be possible, we must rethink the energy source.

Published
2022

4. Improving social justice in observational studies: protocol for the development of a global and Indigenous STROBE-equity reporting guideline

Author

Funnell, Sarah, Jull, Janet, Mbuagbaw, Lawrence, Welch, Vivian, Dewidar, Omar, Wang, Xiaoqin, Lesperance, Miranda, Ghogomu, Elizabeth, Rizvi, Anita, Akl, Elie A., Avey, Marc T., Antequera, Alba, Bhutta, Zulfiqar A., Chamberlain, Catherine, Craig, Peter, Cuervo, Luis Gabriel, Dicko, Alassane, Ellingwood, Holly, Feng, Cindy, Francis, Damian, Greer-Smith, Regina, Hardy, Billie-Jo, Harwood, Matire, Hatcher-Roberts, Janet, Horsley, Tanya, Juando-Prats, Clara, Kasonde, Mwenya, Kennedy, Michelle, Kredo, Tamara, Krentel, Alison, Kristjansson, Elizabeth, Langer, Laurenz, Little, Julian, Loder, Elizabeth, Magwood, Olivia, Mahande, Michael Johnson, Melendez-Torres, G. J., Moore, Ainsley, Niba, Loveline Lum, Nicholls, Stuart G., Nkangu, Miriam Nguilefem, Lawson, Daeria O., Obuku, Ekwaro, Okwen, Patrick, Pantoja, Tomas, Petkovic, Jennifer, Petticrew, Mark, Pottie, Kevin, Rader, Tamara, Ramke, Jacqueline, Riddle, Alison, Shamseer, Larissa, Sharp, Melissa, Shea, Bev, Tanuseputro, Peter, Tugwell, Peter, Tufte, Janice, Von Elm, Erik, Waddington, Hugh Sharma, Wang, Harry, Weeks, Laura, Wells, George, White, Howard, Wiysonge, Charles Shey, Wolfenden, Luke, and Young, Taryn

Published
2023
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6. Prioritising Cochrane reviews to be updated with health equity focus

Author

Tomlinson, Eve, Pardo Pardo, Jordi, Sivesind, Torunn, Szeto, Mindy D, Laughter, Melissa, Foxlee, Ruth, Brown, Michael, Skoetz, Nicole, Dellavalle, Robert P, VA Franco, Juan, Clarke, Mike, Krentel, Alison, Reveiz, Ludovic, Saran, Ashrita, Tse, Frances, A Wells, George, Boyle, Robert, Hilgart, Jennifer, Ndi, Euphrasia Ebai-Atuh, Welch, Vivian, Petkovic, Jennifer, and Tugwell, Peter

Published
2023
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8. Author Correction: Global diversity and biogeography of bacterial communities in wastewater treatment plants

Author

Wu, Linwei, Ning, Daliang, Zhang, Bing, Li, Yong, Zhang, Ping, Shan, Xiaoyu, Zhang, Qiuting, Brown, Mathew Robert, Li, Zhenxin, Van Nostrand, Joy D, Ling, Fangqiong, Xiao, Naijia, Zhang, Ya, Vierheilig, Julia, Wells, George F, Yang, Yunfeng, Deng, Ye, Tu, Qichao, Wang, Aijie, Zhang, Tong, He, Zhili, Keller, Jurg, Nielsen, Per H, Alvarez, Pedro JJ, Criddle, Craig S, Wagner, Michael, Tiedje, James M, He, Qiang, Curtis, Thomas P, Stahl, David A, Alvarez-Cohen, Lisa, Rittmann, Bruce E, Wen, Xianghua, and Zhou, Jizhong

Subjects
Microbiology, Biological Sciences, Global Water Microbiome Consortium, Medical Microbiology
Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Published
2019

9. Association Between the Access Site for Coronary Angiography and Catheter-induced Coronary Artery Dissection

Author

Di Santo, Pietro, Boland, Paul W., Abdel-Razek, Omar, Simard, Trevor, Jung, Richard G., Parlow, Simon, Motazedian, Pouya, Joseph, Joanne, Theriault-Lauzier, Pascal, Alomar, Ali, Hillani, Ali, Alhassani, Saad, Ali, Mohamed Bayoumi, Kyeremanteng, Kwadwo, Coyle, Doug, Fergusson, Dean, Wells, George A., Froeschl, Michael, Labinaz, Marino, Russo, Juan J., and Hibbert, Benjamin

Published
2023
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12. Abstract 13954: The Canadian Tia Score as a Predictor of Ischemic Lesion on Magnetic Resonance Imaging in Transient Ischemic Attack or Minor Stroke Following a Negative Computed Tomography Scan

Author

Robitaille, Matthieu, Sharma, Mukul, Emond, Marcel, Mackey, Ariane, Blanchard, Pierre-Gilles, Nemnom, Marie-Joe, Sivilotti, Marco, STIELL, Ian, Stotts, Grant, Lee, Jacques, Worster, Andrew, Morris, Judy, Cheung, Ka Wai, Jin, Albert, Oczkowski, Wieslaw J, Sahlas, Demetrios, Murray, Heather, Verreault, Steve, Camden, Marie-Christine, Yip, Samuel, Teal, Philip A, GLADSTONE, David J, Boulos, Mark, Chagnon, Nicholas, Shouldice, Elizabeth, Atzema, Clare, Slaoui, Tarik, Teitelbaum, Jeanne S, Wells, George A, and Perry, Jeffrey J

Published
2023
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14. Point of Care Clinical Risk Score to Improve the Negative Diagnostic Utility of an Agatston Score of Zero: Averting the Need for Coronary Computed Tomography Angiography.

Author

Alshahrani, Ali M, Mahmood, Hamza, Wells, George A, Hossain, Alomgir, Rybicki, Frank J, Achenbach, Stephan, Al-Mallah, Mouaz H, Andreini, Daniele, Bax, Jeroen J, Berman, Daniel S, Budoff, Matthew J, Cademartiri, Filippo, Callister, Tracy Q, Chang, Hyuk-Jae, Chinnaiyan, Kavitha, Cury, Ricardo C, DeLago, Augustin, Feuchtner, Gudrun, Hadamitzky, Martin, Hausleiter, Joerg, Kaufmann, Philipp A, Kim, Yong-Jin, Leipsic, Jonathon A, Maffei, Erica, Marques, Hugo, Pontone, Gianluca, Raff, Gilbert, Rubinshtein, Ronen, Shaw, Leslee J, Villines, Todd C, Lin, Fay Y, Min, James K, and Chow, Benjamin J

Subjects
Humans, Coronary Stenosis, Registries, Risk Assessment, Risk Factors, Retrospective Studies, Predictive Value of Tests, Algorithms, Middle Aged, Unnecessary Procedures, Point-of-Care Systems, Female, Male, Computed Tomography Angiography, chest pain, coronary artery disease, diabetes mellitus, humans, registries, Prevention, Cardiovascular, Atherosclerosis, Clinical Research, Heart Disease - Coronary Heart Disease, Biomedical Imaging, Heart Disease, 4.2 Evaluation of markers and technologies, Clinical Sciences, Cardiovascular System & Hematology
Abstract

BackgroundCoronary artery calcification is a marker of underlying atherosclerotic vascular disease. The absence of coronary artery calcification is associated with a low prevalence of obstructive coronary artery disease (CAD), but it cannot be ruled out completely. We sought to develop a clinical tool that can be added to Agatston score of zero to rule out obstructive CAD with high accuracy.MethodsWe developed a clinical score retrospectively from a cohort of 4903 consecutive patients with an Agatston score of zero. Patients with prior diagnosis of CAD, coronary percutaneous coronary intervention, or surgical revascularization were excluded. Obstructive CAD was defined as any epicardial vessel diameter narrowing of ≥50%. The score was validated using an external cohort of 4290 patients with an Agatston score of zero from a multinational registry.ResultsThe score consisted of 7 variables: age, sex, typical chest pain, dyslipidemia, hypertension, family history, and diabetes mellitus. The model was robust with an area under the curve of 0.70 (95% CI, 0.65-0.76) in the derivation cohort and 0.69 (95% CI, 0.65-0.72) in the validation cohort. Patients were divided into 3 risk groups based on the score: low (≤6), intermediate (7-13), and high (≥14). Patients who score ≤6 have a negative likelihood ratio of 0.42 for obstructive CAD, whereas those who score ≥14 have a positive likelihood ratio of >5.5 for obstructive CAD. The outcome was ruled out in >98% of patients with a score ≤6 in the validation cohort.ConclusionsWe developed a score that may be used to identify the likelihood of obstructive CAD in patients with an Agatston score of zero, which may be used to direct the need for additional testing. However, the results of this retrospective analysis are hypothesis generating and before clinical implementation should be validated in a trial with a prospectively collected data.

Published
2019

15. Global diversity and biogeography of bacterial communities in wastewater treatment plants

Author

Wu, Linwei, Ning, Daliang, Zhang, Bing, Li, Yong, Zhang, Ping, Shan, Xiaoyu, Zhang, Qiuting, Brown, Mathew Robert, Li, Zhenxin, Van Nostrand, Joy D, Ling, Fangqiong, Xiao, Naijia, Zhang, Ya, Vierheilig, Julia, Wells, George F, Yang, Yunfeng, Deng, Ye, Tu, Qichao, Wang, Aijie, Zhang, Tong, He, Zhili, Keller, Jurg, Nielsen, Per H, Alvarez, Pedro JJ, Criddle, Craig S, Wagner, Michael, Tiedje, James M, He, Qiang, Curtis, Thomas P, Stahl, David A, Alvarez-Cohen, Lisa, Rittmann, Bruce E, Wen, Xianghua, and Zhou, Jizhong

Subjects
Microbiology, Biological Sciences, Ecology, Infection, Bacteria, Biodiversity, DNA, Bacterial, Geography, Microbiota, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Sewage, Water Purification, Global Water Microbiome Consortium, Medical Microbiology
Abstract

Microorganisms in wastewater treatment plants (WWTPs) are essential for water purification to protect public and environmental health. However, the diversity of microorganisms and the factors that control it are poorly understood. Using a systematic global-sampling effort, we analysed the 16S ribosomal RNA gene sequences from ~1,200 activated sludge samples taken from 269 WWTPs in 23 countries on 6 continents. Our analyses revealed that the global activated sludge bacterial communities contain ~1 billion bacterial phylotypes with a Poisson lognormal diversity distribution. Despite this high diversity, activated sludge has a small, global core bacterial community (n = 28 operational taxonomic units) that is strongly linked to activated sludge performance. Meta-analyses with global datasets associate the activated sludge microbiomes most closely to freshwater populations. In contrast to macroorganism diversity, activated sludge bacterial communities show no latitudinal gradient. Furthermore, their spatial turnover is scale-dependent and appears to be largely driven by stochastic processes (dispersal and drift), although deterministic factors (temperature and organic input) are also important. Our findings enhance our mechanistic understanding of the global diversity and biogeography of activated sludge bacterial communities within a theoretical ecology framework and have important implications for microbial ecology and wastewater treatment processes.

Published
2019

19. Prospective Validation of Computed Tomography to Identify Patients at High Risk for Stroke After Transient Ischemic Attack or Minor Stroke

Author

Ferguson, Emma, Yadav, Krishan, Sharma, Mukul, Sivilotti, Marco L.A., Émond, Marcel, Stiell, Ian G., Stotts, Grant, Lee, Jacques S., Worster, Andrew, Morris, Judy, Cheung, Ka Wai, Jin, Albert Y., Oczkowski, Wieslaw J., Sahlas, Demetrios J., Murray, Heather E., Mackey, Ariane, Verreault, Steve, Camden, Marie-Christine, Yip, Samuel, Teal, Philip, Gladstone, David J., Boulos, Mark I., Chagnon, Nicolas, Shouldice, Elizabeth, Atzema, Clare, Slaoui, Tarik, Teitelbaum, Jeanne, Nemnom, Marie-Joe, Wells, George A., Nath, Avik, and Perry, Jeffrey J.

Published
2023
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22. Reporting of equity in observational epidemiology: A methodological review

Author

Dewidar, Omar, primary, Al-Zubaidi, Ali, additional, Bondok, Mostafa, additional, Abdelrazeq, Leenah, additional, Huang, Jimmy, additional, Jearvis, Alyssa, additional, Barker, Lucy C, additional, Elmestekawy, Nour, additional, Goghomu, Elizabeth, additional, Rader, Tamara, additional, Tufte, Janice, additional, Greer-Smith, Regina, additional, Waddington, Hugh S, additional, Nicholls, Stuart G, additional, Little, Julian, additional, Hardy, Billie-Jo, additional, Horsley, Tanya, additional, Young, Taryn, additional, Cuervo, Luis Gabriel, additional, Sharp, Melissa K, additional, Chamberlain, Catherine, additional, Shea, Beverley, additional, Craig, Peter, additional, Lawson, Daeria O, additional, Rizvi, Anita, additional, Wiysonge, Charles S, additional, Kredo, Tamara, additional, Francis, Damian, additional, Kristjansson, Elizabeth, additional, Bhutta, Zulfiqar, additional, Antequera, Alba, additional, Melendez-Torres, GJ, additional, Pantoja, Tomas, additional, Wang, Xiaoqin, additional, Jull, Janet, additional, Roberts, Janet Hatcher, additional, Funnell, Sarah, additional, White, Howard, additional, Krentel, Alison, additional, Mahande, Michael Johnson, additional, Ramke, Jacqueline, additional, Wells, George, additional, Petkovic, Jennifer, additional, Pottie, Kevin, additional, Niba, Loveline, additional, Feng, Cindy, additional, Nguliefem, Miriam N, additional, Tugwell, Peter, additional, Mbuagbaw, Lawrence, additional, and Welch, Vivian, additional

Published
2024
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25. Options for basing Dietary Reference Intakes (DRIs) on chronic disease endpoints: report from a joint US-/Canadian-sponsored working group 1–3

Author

Yetley, Elizabeth A, MacFarlane, Amanda J, Greene-Finestone, Linda S, Garza, Cutberto, Ard, Jamy D, Atkinson, Stephanie A, Bier, Dennis M, Carriquiry, Alicia L, Harlan, William R, Hattis, Dale, King, Janet C, Krewski, Daniel, O’Connor, Deborah L, Prentice, Ross L, Rodricks, Joseph V, and Wells, George A

Subjects
Nutrition, Obesity, Good Health and Well Being, Aged, Canada, Chronic Disease, Diet, Humans, Nutrition Assessment, Nutritional Requirements, Nutritional Status, Recommended Dietary Allowances, Reference Values, United States, Dietary Reference Intakes, chronic disease, intake response, evidentiary challenges, evidence assessments, Engineering, Medical and Health Sciences, Nutrition & Dietetics
Abstract

Dietary Reference Intakes (DRIs) are used in Canada and the United States in planning and assessing diets of apparently healthy individuals and population groups. The approaches used to establish DRIs on the basis of classical nutrient deficiencies and/or toxicities have worked well. However, it has proved to be more challenging to base DRI values on chronic disease endpoints; deviations from the traditional framework were often required, and in some cases, DRI values were not established for intakes that affected chronic disease outcomes despite evidence that supported a relation. The increasing proportions of elderly citizens, the growing prevalence of chronic diseases, and the persistently high prevalence of overweight and obesity, which predispose to chronic disease, highlight the importance of understanding the impact of nutrition on chronic disease prevention and control. A multidisciplinary working group sponsored by the Canadian and US government DRI steering committees met from November 2014 to April 2016 to identify options for addressing key scientific challenges encountered in the use of chronic disease endpoints to establish reference values. The working group focused on 3 key questions: 1) What are the important evidentiary challenges for selecting and using chronic disease endpoints in future DRI reviews, 2) what intake-response models can future DRI committees consider when using chronic disease endpoints, and 3) what are the arguments for and against continuing to include chronic disease endpoints in future DRI reviews? This report outlines the range of options identified by the working group for answering these key questions, as well as the strengths and weaknesses of each option.

Published
2017

26. Defining domains: developing consensus-based definitions for foundational domains in OMERACT core outcome sets

Author

Maxwell, Lara J., Jones, Caitlin, Bingham, Clifton O, Boers, Maarten, Boonen, Annelie, Choy, Ernest, Christensen, Robin, Conaghan, Philip G., D'Agostino, Maria Antonietta, Doria, Andrea S., Grosskleg, Shawna, Hill, Catherine L., Hofstetter, Catherine, Horgan, Ben, Kroon, Féline, Leung, Ying Ying, Mackie, Sarah, Meara, Alexa, Shea, Beverley J, Simon, Lee S, Touma, Zahi, Tugwell, Peter, Wells, George A, Beaton, Dorcas E, D'Agostino, Maria Antonietta (ORCID:0000-0002-5347-0060), Maxwell, Lara J., Jones, Caitlin, Bingham, Clifton O, Boers, Maarten, Boonen, Annelie, Choy, Ernest, Christensen, Robin, Conaghan, Philip G., D'Agostino, Maria Antonietta, Doria, Andrea S., Grosskleg, Shawna, Hill, Catherine L., Hofstetter, Catherine, Horgan, Ben, Kroon, Féline, Leung, Ying Ying, Mackie, Sarah, Meara, Alexa, Shea, Beverley J, Simon, Lee S, Touma, Zahi, Tugwell, Peter, Wells, George A, Beaton, Dorcas E, and D'Agostino, Maria Antonietta (ORCID:0000-0002-5347-0060)

Abstract

Objective: To develop a set of detailed definitions for foundational domains commonly used in OMERACT (Outcome Measures in Rheumatology) core domain sets. Methods: We identified candidate domain definitions from prior OMERACT publications and websites and publications of major organizations involved in outcomes research for six domains commonly used in OMERACT Core Domain Sets: pain intensity, pain interference, physical function, fatigue, patient global assessment, and health-related quality of life. We conducted a two-round survey of OMERACT working groups, patient research partners, and then the OMERACT Technical Advisory Group to establish their preferred domain definitions. Results were presented at the OMERACT 2023 Methodology Workshop, where participants discussed their relevant lived experience and identified potential sources of variability giving the needed detail in our domain definitions. Results: One-hundred four people responded to both rounds of the survey, and a preferred definition was established for each of the domains except for patient global assessment for which no agreement was reached. Seventy-five participants at the OMERACT 2023 Methodology Workshop provided lived experience examples, which were used to contextualise domain definition reports for each of the five domains. Conclusion: Using a consensus-based approach, we have created a detailed definition for five of the foundational domains in OMERACT core domain sets; patient global assessment requires further research. These definitions, although not mandatory for working groups to use, may facilitate the initial domain-match assessment step of instrument selection, and reduce the time and resources required by future OMERACT groups when developing core outcome sets.

Published
2024

27. Growth and defect formation in graphene

Author

Wells, George Henry

Subjects
547
Abstract

In this work, few-layer graphene (FLG) was grown from SiC(0001) with temperature, growth time and cooling rate as variables. Samples were characterised by Scanning Tunnelling Microscopy (STM), Low Energy Electron Diraction (LEED), Auger Electron Spectroscopy (AES) and Raman Spectroscopy (RS) to determine graphene quality. The information obtained from these techniques was then used to determine optimal conditions for growing graphene from SiC(0001). Contamination on graphene lms is also discussed and a facile method for the removal of large scale metal contaminant layers from the surface is described. To study adhesion of FLG to a substrate, a continuum energy model was developed to obtain the adhesion energy via the measurement of pleat defects by STM. This model was applied to graphene grown from SiC(0001) and its adhesion energy was found to be signicantly larger than the those measured for graphene on other substrates. Variation of pleat defects on graphene grown from SiC(0001) with dierent growth parameters was also studied by STM. The factors that aect the dimensions and concentration of pleats were determined and discussed in relation to the quality of the lm. Further investigation was conducted on the stability of pleat defects under STM imaging, with the presence of contamination and defects found to have a signicant eect in reducing the dragging of pleats by the probe tip. A comparative study of the dynamics of extrinsic defects on FLG and graphite is also presented in this work. Samples were bombarded with 0.2 keV Ar+ ions, heated to dierent temperatures and studied with STM. The concentration, mobility, agglomeration and alignment of defects was examined and mechanisms suggested for the behaviour observed. The Local Density of States (LDOS) at defect sites of both graphite and FLG were studied by Scanning Tunnelling Spectroscopy (STS) to determine if signicant dierences in electronic structure due to defects were observed between the two systems. Preliminary experiments to optimise the growth of graphene on Cu substrates by \hot-wall" and \cold-wall" methods have been performed, to determine whether cold-wall growth presents a viable alternative to hot-wall for the production of high quality graphene. Graphene was grown by both methods using dierent growth periods to determine the optimal growth time for each method. The use of evaporated Cu on SiO2 as growth substrates is also discussed. Samples produced by both methods were studied by Scanning Electron Microscopy (SEM) to determine their quality. Electron Back-Scatter Diraction (EBSD) measurements were also performed on samples produced by both methods to determine the extent to which Cu grain orientation aects the growth of graphene.

Published
2016

32. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions

Author

Sterne, Jonathan Ac, Hernán, Miguel A, Reeves, Barnaby C, Savović, Jelena, Berkman, Nancy D, Viswanathan, Meera, Henry, David, Altman, Douglas G, Ansari, Mohammed T, Boutron, Isabelle, Carpenter, James R, Chan, An-Wen, Churchill, Rachel, Deeks, Jonathan J, Hróbjartsson, Asbjørn, Kirkham, Jamie, Jüni, Peter, Loke, Yoon K, Pigott, Theresa D, Ramsay, Craig R, Regidor, Deborah, Rothstein, Hannah R, Sandhu, Lakhbir, Santaguida, Pasqualina L, Schünemann, Holger J, Shea, Beverly, Shrier, Ian, Tugwell, Peter, Turner, Lucy, Valentine, Jeffrey C, Waddington, Hugh, Waters, Elizabeth, Wells, George A, Whiting, Penny F, and Higgins, Julian Pt

Subjects
Epidemiology, Health Sciences, Clinical Trials and Supportive Activities, Clinical Research, Prevention, Generic health relevance, Bias, Clinical Trials as Topic, Confounding Factors, Epidemiologic, Humans, Observational Studies as Topic, Pilot Projects, Risk, Statistics as Topic, Clinical Sciences, Public Health and Health Services, General & Internal Medicine, Biomedical and clinical sciences, Health sciences, Psychology
Abstract

Non-randomised studies of the effects of interventions are critical to many areas of healthcare evaluation, but their results may be biased. It is therefore important to understand and appraise their strengths and weaknesses. We developed ROBINS-I (“Risk Of Bias In Non-randomised Studies - of Interventions”), a new tool for evaluating risk of bias in estimates of the comparative effectiveness (harm or benefit) of interventions from studies that did not use randomisation to allocate units (individuals or clusters of individuals) to comparison groups. The tool will be particularly useful to those undertaking systematic reviews that include non-randomised studies.

Published
2016

33. Spontaneous Coronary Artery Dissection Across the Health Care Pathway: A National, Multicenter, Patient‐Informed Investigation

Author

Bouchard, Karen, primary, Lalande, Kathleen, additional, Coutinho, Thais, additional, Mulvagh, Sharon, additional, Pacheco, Christine, additional, Liu, Shuangbo, additional, Saw, Jacqueline, additional, So, Derek, additional, Reed, Jennifer L., additional, Chiarelli, Alexandra, additional, Stragapede, Elisa, additional, Robert, Helen, additional, Lappa, Nadia, additional, Sun, Louise, additional, Wells, George, additional, and Tulloch, Heather, additional

Published
2023
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37. PROTOCOL: Mass Deworming for Improving Health and Cognition of Children in Endemic Helminth Areas--A Systematic Review and Individual Participant Data Network Meta-Analysis

Author

Welch, Vivian, Ghogomu, Elizabeth, Hossain, Alomgir, Arora, Paul, Cousens, Simon, Gaffey, Michelle, Riddle, Alison, Salam, Rehana, Tugwell, Peter, Bhutta, Zulfiqar, and Wells, George A.

Abstract

Soil transmitted (or intestinal) helminths and schistosomes affect millions of children worldwide. There are four species of soil transmitted helminths: "Ascaris lumbricoides" (roundworm), "Necator americanus" and "Ancylostoma duodenale" (hookworms), and "Trichuris trichura" (whipworm). The five species of schistosomes which affect humans include: "Schistosoma (S.) mansoni," "Schistosoma japonicum," "Schistosoma mekongi," "Schistosoma intercalatum" (which cause intestinal schistosomiasis) and "Schistosoma haematobium" (which causes urinary schistosomiasis). Mass deworming is applied widely to reduce the consequences of helminth infection, and there have been numerous studies on the effects of deworming on growth, cognition and learning outcomes in children over the past several decades. Systematic reviews and meta-analyses based on aggregate results of the effect of mass deworming on health and education outcomes are conflicting with some showing benefit (Hall, Hewitt et al. 2008; Croke, Hicks et al. 2016) and others not (Taylor-Robinson, Maayan et al. 2015; Welch, Ghogomu et al. 2017). Debate has ensued about whether these conflicting results are due to the influence of variations in effect across individual-level characteristics such as whether children are infected or not and intensity of infection (Hotez, Molyneux et al. 2007; Bundy, Kremer et al. 2009; Montresor, Addiss et al. 2015) as well as setting characteristics such as the sanitation environment and rapidity of reinfection (Campbell, Nery et al.). This meta-analysis will explore the question of whether mass deworming is more effective for subgroups of children defined by characteristics such as infection intensity or status, age or nutritional status. This understanding could help to develop targeted strategies to reach these children better with deworming and guide policy regarding deworming. [The following advisory group members co-authored this article: Robert Black, Celia Holland, Deirdre Hollingsworth, Sue Horton, and Sanjay Wijeseker.]

Published
2018
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41. The Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE): protocol for a randomised, double-blind, placebo-controlled trial

Author

Boczar, Kevin Emery, primary, Shin, Sheojung, additional, deKemp, Robert A, additional, Dowlatshahi, Dar, additional, Tavoosi, Anahita, additional, Wiefels, Christiane, additional, Liu, Peter, additional, Lochnan, Heather, additional, MacPherson, Paul A, additional, Chong, Aun Yeong, additional, Torres, Carlos, additional, Leung, Eugene, additional, Tawakol, Ahmed, additional, Ahmadi, Ali, additional, Garrard, Linda, additional, Lefebvre, Chantal, additional, Kelly, Cathy, additional, MacPhee, Poppy, additional, Tilokee, Everad, additional, Raggi, Paolo, additional, Wells, George A, additional, and Beanlands, Rob, additional

Published
2023
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42. Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy

Author

Chih, Sharon, primary, Tavoosi, Anahita, additional, Nair, Vidhya, additional, Chong, Aun Yeong, additional, Džavík, Vladimír, additional, Aleksova, Natasha, additional, So, Derek Y., additional, deKemp, Robert A., additional, Amara, Ines, additional, Wells, George A., additional, Bernick, Jordan, additional, Overgaard, Christopher B., additional, Celiker-Guler, Emel, additional, Mielniczuk, Lisa M., additional, Stadnick, Ellamae, additional, McGuinty, Caroline, additional, Ross, Heather J., additional, and Beanlands, Rob S.B., additional

Published
2023
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43. The Prevalence and Characteristics of Arrhythmic Mitral Valve Prolapse in Patients With Unexplained Cardiac Arrest

Author

Alqarawi, Wael, primary, Tadros, Rafik, additional, Roberts, Jason D., additional, Cheung, Christopher C., additional, Green, Martin S., additional, Burwash, Ian G., additional, Steinberg, Christian, additional, Healey, Jeffrey S., additional, Khan, Habib, additional, McIntyre, Ciorsti, additional, Cadrin-Touringy, Julia, additional, Laksman, Zachary W.M., additional, Simpson, Christopher S., additional, Sanatani, Shubhayan, additional, Gardner, Martin, additional, Angaran, Paul, additional, Ilhan, Erkan, additional, Talajic, Mario, additional, Arbour, Laura, additional, Leather, Richard, additional, Seifer, Colette, additional, Joza, Jacqueline, additional, Lee, Felicity, additional, Lau, Lawrence, additional, Nair, Girish, additional, Wells, George, additional, and Krahn, Andrew D., additional

Published
2023
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44. Benefit of hospital admission for detecting serious adverse events among emergency department patients with syncope: a propensity-score-matched analysis of a multicentre prospective cohort

Author

Krishnan, Rohin J., Mukarram, Muhammad, Ghaedi, Bahareh, Sivilotti, Marco L.A., Sage, Natalie Le, Yan, Justin W., Huang, Paul, Hegdekar, Mona, Mercier, Eric, Nemnom, Marie-Joe, Calder, Lisa A., McRae, Andrew D., Rowe, Brian H., and Wells, George A.

Subjects
Hospital emergency services -- Analysis, Hospital admission and discharge -- Analysis, Medical research -- Analysis, Fainting -- Complications and side effects, Health
Abstract

BACKGROUND: The benefit of hospital admission after emergency department evaluation for syncope is unclear. We sought to determine the association between hospital admission and detection of serious adverse events, and whether this varied according to the Canadian Syncope Risk Score (CSRS). METHODS: We conducted a secondary analysis of a multicentre prospective cohort of patients assessed in the emergency department for syncope. We compared patients admitted to hospital and discharged patients, using propensity scores to match 1:1 for risk of a serious adverse event. The primary outcome was detection of a serious adverse event in hospital for admitted patients or within 30 days after emergency department disposition for discharged patients. RESULTS: We included 8183 patients, of whom 743 (9.1%) were admitted; 658/743 (88.6%) were matched. Admitted patients had higher odds of detection of a serious adverse event (odds ratio [OR] 5.0, 95% confidence interval [CI] 3.3-7.4), nonfatal arrhythmia (OR 5.1, 95% CI 2.9-8.8) and nonarrhythmic serious adverse event (OR 6.3, 95% CI 2.9-13.5). There were no significant differences between the 2 groups in death (OR 1.0, 95% CI 0.4-2.7) or detection of ventricular arrhythmia (OR 2.0, 95% CI 0.7-6.0). Differences between admitted and discharged patients in detection of serious adverse events were greater for those with a CSRS indicating medium to high risk (p = 0.04). INTERPRETATION: Patients with syncope were more likely to have serious adverse events identified within 30 days if they were admitted to hospital rather than discharged from the emergency department. However, the benefit of hospital admission is low for patients at low risk of a serious adverse event., Syncope accounts for 1%-2% of all emergency department visits. (1) Although syncopal events are usually benign, a serious underlying condition (e.g., arrythmia, myocardial infarction, severe hemorrhage) is identified within 30 [...]

Published
2020
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47. OUTSMART HF: A Randomized Controlled Trial of Routine Versus Selective Cardiac Magnetic Resonance for Patients with Non-Ischemic Heart Failure (IMAGE-HF 1B)

Author

Paterson, D. Ian, Wells, George, Erthal, Fernanda, Mielniczuk, Lisa, O’Meara, Eileen, White, James, Connelly, Kim A., Knuuti, Juhani, Radja, Miroslaw, Laine, Mika, Chow, Benjamin J.W., Kandolin, Riina, Chen, Li, Dick, Alexander, Dennie, Carole, Garrard, Linda, Ezekowitz, Justin, Beanlands, Rob, and Chan, Kwan-Leung

Published
2020
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