24 results on '"Rees, Gwyn"'
Search Results
2. Impact of diabetic retinopathy on patients' beliefs about diabetes.
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Rees, Gwyn, Sasongko, Muhammad B, Fenwick, Eva K, Nicolaou, Theona E, Wong, Tien Y, and Lamoureux, Ecosse L
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DIABETIC retinopathy , *GLYCEMIC index , *HEMOGLOBINS , *BEHAVIORAL assessment , *DIABETES complications - Abstract
Background: The aim was to compare beliefs about diabetes and determine their associations with psychological well-being, self-management behaviour and glycaemic control in those with and without diabetic retinopathy (DR). Methods: We recruited 400 patients with diabetes aged 18 years or more from specialised eye clinics, as part of the Diabetes Management Project (DMP). Two-field retinal photographs were taken to assess DR and detailed clinical and psychological well-being examinations were performed following standardised procedures. Glycaemic control was determined using glycated haemoglobin levels. We assessed beliefs about diabetes (diabetes-specific version of the Revised Illness Perception Questionnaire [IPQ-R]), self-management behaviour (Summary of Diabetes Self Care Activities [SDSCA]) questionnaire) and depression and anxiety (the Hospital Anxiety and Depression Scale [HADS]). Results: Patients with DR (n = 256, 64 per cent) believed that they experienced more symptoms related to their diabetes, that diabetes had a greater impact on their life and that this condition was more unpredictable compared with those without DR (p < 0.05 for all). Patients with DR were also more engaged in glucose testing compared with those without DR. Furthermore, negative beliefs about diabetes were significantly associated with higher levels of depression and anxiety (p < 0.01) but not glycaemic control, regardless of DR and other diabetic complications. Conclusions: Patients with DR had more negative beliefs about diabetes than those without. We identified strong and consistent associations between negative beliefs and psychological outcomes regardless of diabetic complications. These findings suggest that management for patients with DR could include strategies to address negative beliefs about diabetes and manage the emotional implications of diabetes in addition to medical treatment. [ABSTRACT FROM AUTHOR]
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- 2012
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3. Social and emotional impact of diabetic retinopathy: a review.
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Fenwick, Eva, Rees, Gwyn, Pesudovs, Konrad, Dirani, Mohamed, Kawasaki, Ryo, Wong, Tien Y, and Lamoureux, Ecosse
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DIABETIC retinopathy , *QUALITY of life , *DISEASE management , *PSYCHOLOGICAL stress , *DISEASE progression , *MENTAL health - Abstract
A bstract People with vision-threatening diabetic retinopathy are likely to experience enhanced social and emotional strain. Critically, those with both vision-threatening diabetic retinopathy and psychosocial problems may have significantly reduced levels of functioning compared with psychologically healthy counterparts. This can cause inadequate compliance, increased strain on family functioning, worse diabetes control, increased progression of diabetic retinopathy and, consequently, further psychosocial stress resulting in a number of concerning implications for disease management, clinical outcomes and healthcare costs. However, the emotional and social health consequences of diabetic retinopathy have not yet been systematically explored. This information is crucial as it allows for a targeted approach to treatment and prevention and avoidance of the potentially detrimental implications described above. Therefore, this paper reviews the current qualitative and quantitative evidence regarding the social and emotional impact of diabetic retinopathy and identifies directions for future research. Key search terms were applied to the electronic databases Pubmed, ISI Web of Science and Embase and the bibliographies of relevant papers were systematically reviewed for additional references. Overall, the evidence suggests that diabetic retinopathy and associated vision loss have several debilitating effects, including disruption of family functioning, relationships and roles; increased social isolation and dependence; and deterioration of work prospects resulting in increased financial strain. Adverse emotional responses include fear, anxiety, vulnerability, guilt, loss of confidence, anger, stress and self-perception issues. However, the research to date is largely qualitative in nature, with most quantitative studies being small, cross-sectional and somewhat outdated. Similarly, the outcome measures used in many studies to date are suboptimal in terms of content and validity. Therefore, this review identifies the need for improved outcome measures to provide valid, meaningful measurement of the social and emotional impact of diabetic retinopathy and discusses potential directions for future research such as item banking and computer adaptive testing. [ABSTRACT FROM AUTHOR]
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- 2012
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4. Letters.
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Little, Sam, Rees, Gwyn, Palmer, Matt, O'Danachair, Donal, Sams, Gregory, Bieleski, Paul, Latter, David, Thomas, Lloyd, Campbell, Timothy, Tremmel, Georg, Gray, John, Anthony, Simon, and Thompson, Jennifer
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LETTERS to the editor , *GLOBAL temperature changes , *CLIMATOLOGY , *GLOBAL warming , *CARBON dioxide , *GLACIERS - Abstract
Presents several letters to the editor on science. Impact of the global warming, on climatology; Effect of increased carbon dioxide levels on forest growth; Assessment of the potential impacts of deglaciation on the water resources of the Himalayas.
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- 2004
5. The relationship between diabetic retinopathy and psychosocial functioning: a systematic review.
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Khoo, Krystal, Man, Ryan E. K., Rees, Gwyn, Gupta, Preeti, Lamoureux, Ecosse L., and Fenwick, Eva K.
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DIABETIC retinopathy , *META-analysis , *LONGITUDINAL method , *QUALITY of life , *MENTAL health - Abstract
Importance: Previous work has reported a link between diabetic retinopathy/diabetic macular edema (DR/DME) and psychosocial functioning, although the extent and direction of the association remains uncertain.Objective: To determine the relationship between DR/DME and psychosocial functioning, the latter an umbrella term used to capture the emotional and social aspects of functioning which may include, for example, depression; depressive disorder; anxiety; vision-specific distress; diabetes-specific distress and emotional and social well-being.Evidence Review: PubMed, Embase, Medline and the Cochrane Central register were systematically searched for relevant interventional and observational quantitative studies using standardised criteria. Studies with DR/DME and psychosocial functioning as exposures or outcomes were accepted. Study quality was evaluated using the modified Newcastle-Ottawa scale for observational studies, and the modified Down's and Black checklist for interventional studies.Findings: Of 1827 titles initially identified, 42 were included in the systematic review. They comprised of four interventions (one RCT, three non-RCTs) and 38 observational studies (33 cross sectional, five prospective). In studies with DR/DME as the exposure (n = 28), its severity and related vision impairment were consistently associated with poor psychosocial outcomes, mostly higher incidence of depression and depressive symptoms. Baseline depression and depressive symptoms were also associated with greater DR incidence and progression of DR. Medical intervention strategies showed significant improvement in psychosocial outcomes in patients with DR, such as significant improvements in mental health domain scores of the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ 25).Conclusion and Relevance: Severity of DR, DME and associated vision loss are significantly associated with poor psychosocial outcomes. Aspects of depression and its symptoms show a bi-directional association, with increased incidence and progression of DR significant in those with baseline depression or depressive symptoms. Based on these findings, we propose two areas that may benefit from targeted interventions: (1) Prevention of development of poor psychological outcomes by preventing and delaying progression of DR/DME; and (2) Improved detection and management of poor psychological functioning by improving screening tools and multidisciplinary care for patients. Subsequent longitudinal studies can further help establish the underlying relationship between the two measures. [ABSTRACT FROM AUTHOR]- Published
- 2019
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6. Improving the representation of groundwater processes in a large-scale water resources model.
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Baron, Helen Elizabeth, Keller, Virginie D. J., Horan, R., MacAllister, Donald John, Simpson, Mike, Jackson, Christopher R., Houghton-Carr, Helen A., Rickards, Nathan, Garg, Kaushal K., Sekhar, Muddu, MacDonald, Alan, and Rees, Gwyn
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WATER supply , *GROUNDWATER , *WATER table , *WATERSHEDS , *STREAMFLOW , *AQUIFERS - Abstract
This study explores whether incorporating a more sophisticated representation of groundwater, and human–groundwater interactions, improves predictive capability in a large-scale water resource model. The Global Water Availability Assessment model (GWAVA) is developed to include a simple layered aquifer and associated fluxes (GWAVA-GW), and applied to the Cauvery River basin in India, a large, human-impacted basin with a high dependence on groundwater. GWAVA-GW shows good predictive skill for streamflow upstream of the Mettur dam: Kling-Gupta efficiency ≥ 0.3 for 91% of sub-catchments, and improved model skill for streamflow prediction compared to GWAVA over the majority of the basin. GWAVA-GW shows some level of predictive skill for groundwater levels over seasonal and long-term time scales, with a tendency to overestimate depth to groundwater in areas with high levels of groundwater pumping. Overall, GWAVA-GW is a useful tool when assessing water resources at a basin scale, especially in areas that rely on groundwater. [ABSTRACT FROM AUTHOR]
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- 2023
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7. Reducing respondent burden: validation of the Brief Impact of Vision Impairment questionnaire.
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Fenwick, Eva, Man, Ryan, Rees, Gwyn, Keeffe, Jill, Wong, Tien, Lamoureux, Ecosse, Fenwick, Eva K, Man, Ryan E K, Wong, Tien Y, and Lamoureux, Ecosse L
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PSYCHOMETRICS , *MEDICAL statistics , *ANALYSIS of variance , *QUALITY of life , *RASCH models , *VISION disorders , *LONGITUDINAL method , *QUESTIONNAIRES , *SICKNESS Impact Profile , *CROSS-sectional method , *FERRANS & Powers Quality of Life Index , *IMPACT of Event Scale , *DIAGNOSIS ,RESEARCH evaluation - Abstract
Purpose: To develop a psychometrically sound and valid Brief Impact of Vision Impairment (IVI) questionnaire.Methods: Cross-sectional data from four prospective studies (2001-2008) were pooled and randomly divided into development/validation sets (n = 416) each. Items with suboptimal psychometric properties were iteratively removed in the development set to form the Brief IVI. Psychometric properties of the Brief IVI were independently tested in the validation sample. Correlation between person measures from the original and Brief IVI was assessed [Pearson r and intraclass correlation coefficient (ICC)]. Criterion validity was determined by testing the Brief IVI's ability to discriminate levels of vision impairment (analysis of variance, ANOVA). Responsiveness was tested by comparing the ICC of the original and Brief IVI data obtained pre-/post-intervention.Results: The 15-item Brief IVI, and its 9-item Visual Functioning and 6-item Emotional Well-being subscales had ordered thresholds, good precision and targeting, unidimensionality, and minimal item misfit (replicated in the validation sample). Brief and original IVI person measures were highly correlated (r = 0.97 and ICC = 0.98, p < 0.001), indicating the Brief IVI provides statistically similar measurement of vision-related quality of life (VRQoL). Brief IVI mean logit scores declined as vision impairment worsened (p = 0.001) demonstrating criterion validity. ICC of the original versus Brief IVI pre-/post-intervention was excellent (0.98), establishing that the Brief IVI was as responsive to changes in VRQoL as the original.Conclusions: The Brief 15-item IVI can obtain valid and responsive measurement of VRQoL with half the items in the original and has potential to reduce respondent burden in QoL studies. [ABSTRACT FROM AUTHOR]- Published
- 2017
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8. Factors Associated with Knowledge of Diabetes in Patients with Type 2 Diabetes Using the Diabetes Knowledge Test Validated with Rasch Analysis.
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Fenwick, Eva K., Xie, Jing, Rees, Gwyn, Finger, Robert P., and Lamoureux, Ecosse L.
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TYPE 2 diabetes , *PSYCHOMETRICS , *PATIENT education , *OPHTHALMOLOGISTS , *SOCIODEMOGRAPHIC factors , *HEALTH outcome assessment , *REGRESSION analysis - Abstract
Objective: In patients with Type 2 diabetes, to determine the factors associated with diabetes knowledge, derived from Rasch analysis, and compare results with a traditional raw scoring method. Research Design & Methods: Participants in this cross-sectional study underwent a comprehensive clinical and biochemical assessment. Diabetes knowledge (main outcome) was assessed using the Diabetes Knowledge Test (DKT) which was psychometrically validated using Rasch analysis. The relationship between diabetes knowledge and risk factors identified during univariate analyses was examined using multivariable linear regression. The results using raw and Rasch-transformed methods were descriptively compared. Results: 181 patients (mean age±standard deviation = 66.97±9.17 years; 113 (62%) male) were included. Using Rasch-derived DKT scores, those with greater education (β = 1.14; CI: 0.25,2.04, p = 0.013); had seen an ophthalmologist (β = 1.65; CI: 0.63,2.66, p = 0.002), and spoke English at home (β = 1.37; CI: 0.43,2.31, p = 0.005) had significantly better diabetes knowledge than those with less education, had not seen an ophthalmologist and spoke a language other than English, respectively. Patients who were members of the National Diabetes Service Scheme (NDSS) and had seen a diabetes educator also had better diabetes knowledge than their counterparts. Higher HbA1c level was independently associated with worse diabetes knowledge. Using raw measures, access to an ophthalmologist and NDSS membership were not independently associated with diabetes knowledge. Conclusions: Sociodemographic, clinical and service use factors were independently associated with diabetes knowledge based on both raw scores and Rasch-derived scores, which supports the implementation of targeted interventions to improve patients' knowledge. Choice of psychometric analytical method can affect study outcomes and should be considered during intervention development. [ABSTRACT FROM AUTHOR]
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- 2013
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9. Impact of early and late age-related macular degeneration on vision-specific functioning.
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Lamoureux, Ecosse L., Mitchell, Paul, Rees, Gwyn, Cheung, Gemmy, Yeo, Ian, Shu Yen Lee, Liu, Erica, and Wong, Tien Y.
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RETINAL degeneration , *RETINOIDS , *FUNDUS oculi , *RHODOPSIN , *EPITHELIUM , *OPHTHALMOLOGY - Abstract
AIM: To assess the impact of early and late age-related macular degeneration (AMD) on vision-specific functioning in Singapore Malays. METHODS: AMD was assessed from fundus photographs. The following endpoints were considered for (a) AMD: no AMD, early AMD, and late AMD; (b) drusen: absence and presence; and (c) retinal pigment epithelium (RPE) abnormality: absence and presence. Vision functioning was assessed using the modified VF-11 scale validated using the Rasch analysis. The overall functioning score was used as the main outcome measure. RESULTS: Retinal photographs and vision functioning data were available only for 3252 participants. After age standardisation, the prevalence of early AMD was 3.5% and late AMD 0.34%. In multivariate models, after adjusting for age, gender, education, level of income, smoking status, ocular condition and hypertension, only late AMD was independently associated with poorer vision functioning when compared with no AMD or early AMD (β (β regression coefficient)=–6.4 (CI –11.7 to –2.1; p=0.01)). Early AMD or its principal components, drusen or RPE abnormality, were not independently associated with vision functioning (p>0.05). In adjusted multinomial logistic regression models, people with late AMD were twice as likely (OR=2.23; 95% CI 1.16 to 7.11) to have low overall functioning than those without AMD. CONCLUSIONS: Late AMD has a significant impact on visual functioning, but early AMD, drusen and RPE changes have no impact. These data highlight the importance of preventive public health strategies targeting patients with early AMD signs in order to prevent progression to late AMD when visual function is compromised. [ABSTRACT FROM AUTHOR]
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- 2011
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10. Management of water resources and low flow estimation for the Himalayan basins of Nepal
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Chalise, Suresh R., Kansakar, Sunil R., Rees, Gwyn, Croker, Karen, and Zaidman, Maxine
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WATER resources development , *MOUNTAINS , *HYDROLOGY - Abstract
Reliable estimates of low flow are extremely important for the monsoonal mountainous areas of the Hindu Kush–Himalayan (HKH) region as people in this region are facing growing problems of water during dry periods in terms of both quality and quantity. Furthermore, increasing evidence of decrease in snow cover and retreat of glaciers due to global warming have been reported from various parts of the HKH, which has serious implications for low flow in the region. However, reliable methods for low flow are difficult to find and lack of hydrometeorological data have inhibited the development of such methods. This has posed serious problems for sustainable management of water resources systems in the region in view of the difficulties in low flow.This paper also discusses a method for low flow estimation in the mountainous regions of Nepal, which shares with other neighbouring areas the complexity in the nature of the terrain and climate, inadequate hydro-meteorological network and insufficient long-term reliable data on hydrometeorology. The method discussed is based on a method developed in the UK, for estimating the hydrological regime at ungauged sites. Regionalization of the flow has been developed applying multi-variate regression analysis of long-term hydro-meteorological data and catchment characteristics. A number of standardised flow duration type curves have been determined, and regression models of the flows and the topographical and geological characteristics of the catchments were established. The mean flow was estimated using the water balance principle where the long-term mean annual runoff is the difference between long-term average annual precipitation and long-term actual evapotranspiration. Regionalization has been carried out by developing grids of hydrological response. The grids allow the flow regime to be estimated at any point on any stream in the mountainous region of the country. This is the first regional method of this kind to be developed to estimate low flows from ungauged catchments in Nepal. Such a method is of great importance for Nepal as well as for the mountainous regions of other countries of the HKH region, as it allows assessment of water availability for the design of small hydropower, irrigation and water supply schemes, and contributes to the economic development and poverty alleviation. [Copyright &y& Elsevier]
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- 2003
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11. Optimizing measurement of vision-related quality of life: a computerized adaptive test for the impact of vision impairment questionnaire (IVI-CAT).
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Fenwick, Eva K., Loe, Bao Sheng, Khadka, Jyoti, Man, Ryan E. K., Rees, Gwyn, and Lamoureux, Ecosse L.
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COMPUTER adaptive testing , *QUALITY of life measurement , *MEASUREMENT errors , *VISION testing , *UNITS of measurement - Abstract
Purpose: To compare the results from a simulated computerized adaptive test (CAT) for the 28-item Impact of Vision Impairment (IVI) questionnaire and the original paper-pencil version in terms of efficiency (main outcome), defined as percentage item reduction.Methods: Using paper-pencil IVI data from 832 participants across the spectrum of vision impairment, item calibrations of the 28-item IVI instrument and its associated 20-item vision-specific functioning (VSF) and 8-item emotional well-being (EWB) subscales were generated with Rasch analysis. Based on these calibrations, CAT simulations were conducted on 1000 cases, with 'high' and 'moderate' precision stopping rules (standard error of measurement [SEM] 0.387 and 0.521, respectively). We examined the average number of items needed to satisfy the stopping rules and the corresponding percentage item reduction, level of agreement between person measures estimated from the full IVI item bank and from the CAT simulations, and item exposure rates (IER).Results: For the overall IVI-CAT, 5 or 9.7 items were required, on average, to obtain moderate or high precision estimates of vision-related quality of life, corresponding to 82.1 and 65.4% item reductions compared to the paper-pencil IVI. Agreement was high between the person measures generated from the full IVI item bank and the IVI-CAT for both the high precision simulation (mean bias, - 0.004 logits; 95% LOA - 0.594 to 0.587) and moderate precision simulation (mean bias, 0.014 logits; 95% LOA - 0.828 to 0.855). The IER for the IVI-CAT in the moderate precision simulation was skewed, with six EWB items used > 40% of the time.Conclusion: Compared to the paper-pencil IVI instrument, the IVI-CATs required fewer items without loss of measurement precision, making them potentially attractive outcome instruments for implementation into clinical trials, healthcare, and research. Final versions of the IVI-CATs are available. [ABSTRACT FROM AUTHOR]- Published
- 2020
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12. Hydrological Forecasts and Projections for Improved Decision-Making in the Water Sector in Europe.
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Samaniego, Luis, Thober, Stephan, Wanders, Niko, Pan, Ming, Rakovec, Oldrich, Sheffield, Justin, Wood, Eric F., Prudhomme, Christel, Rees, Gwyn, Houghton-Carr, Helen, Fry, Matthew, Smith, Katie, Watts, Glenn, Hisdal, Hege, Estrela, Teodoro, Buontempo, Carlo, Marx, Andreas, and Kumar, Rohini
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HYDROLOGICAL forecasting , *WEB-based user interfaces , *ATMOSPHERIC models , *CLIMATE change , *INFORMATION storage & retrieval systems - Abstract
Simulations of water fluxes at high spatial resolution that consistently cover historical observations, seasonal forecasts, and future climate projections are key to providing climate services aimed at supporting operational and strategic planning, and developing mitigation and adaptation policies. The End-to-end Demonstrator for improved decision-making in the water sector in Europe (EDgE) is a proof-of-concept project funded by the Copernicus Climate Change Service program that addresses these requirements by combining a multimodel ensemble of state-of-the-art climate model outputs and hydrological models to deliver sectoral climate impact indicators (SCIIs) codesigned with private and public water sector stakeholders from three contrasting European countries. The final product of EDgE is a water-oriented information system implemented through a web application. Here, we present the underlying structure of the EDgE modeling chain, which is composed of four phases: 1) climate data processing, 2) hydrological modeling, 3) stakeholder codesign and SCII estimation, and 4) uncertainty and skill assessments. Daily temperature and precipitation from observational datasets, four climate models for seasonal forecasts, and five climate models under two emission scenarios are consistently downscaled to 5-km spatial resolution to ensure locally relevant simulations based on four hydrological models. The consistency of the hydrological models is guaranteed by using identical input data for land surface parameterizations. The multimodel outputs are composed of 65 years of historical observations, a 19-yr ensemble of seasonal hindcasts, and a century-long ensemble of climate impact projections. These unique, high-resolution hydroclimatic simulations and SCIIs provide an unprecedented information system for decision-making over Europe and can serve as a template for water-related climate services in other regions. [ABSTRACT FROM AUTHOR]
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- 2019
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13. Combined poor diabetes control indicators are associated with higher risks of diabetic retinopathy and macular edema than poor glycemic control alone.
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Fenwick, Eva K., Xie, Jing, Man, Ryan E. K., Sabanayagam, Charumathi, Lim, Lyndell, Rees, Gwyn, Wong, Tien Y., and Lamoureux, Ecosse L.
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DIABETIC retinopathy , *EDEMA , *GLYCEMIC control , *DIABETES prevention , *BLOOD sampling , *CROSS-sectional method , *DISEASE risk factors - Abstract
Purpose: To examine the association of individual and combined indicators of diabetes control with diabetic retinopathy and diabetic macular edema. Materials and methods: In this clinical, cross-sectional study, 613 adults with type 2 diabetes (372 any diabetic retinopathy; 183 any diabetic macular edema) were examined. Diabetic retinopathy was assessed from fundus photographs; diabetic macular edema from Ocular Coherence Tomography scans; and HbA1c and serum lipid values from fasting blood samples. Poor glucose control was defined as HbA1c≥7%; poor blood pressure control as SBP≥130/DBP≥80; and poor lipid control as total cholesterol:HDL ratio≥4.0. The association of poor glucose control, poor blood pressure control and poor lipid control alone and in combination (poor glucose & blood pressure control; poor glucose & lipid control; poor blood pressure & lipid control; and poor glucose, blood pressure & lipid control) with diabetic retinopathy/diabetic macular edema was examined using multiple logistic regression models. Results: Patients’ mean±standard deviation age was 64.9±11.6 years (57% male). In adjusted models, compared to those with good control of all indicators (n = 99, 18.3%), the odds ratio (95% Confidence Interval) of having any diabetic retinopathy was 2.44 (1.34–4.46), 3.75 (1.75–8.07), 4.64 (2.13–10.12) and 2.28 (1.01–5.16) for poor glucose control only; poor glucose & blood pressure control; poor glucose & lipid control; and poor glucose, blood pressure & lipid control, respectively. Correspondingly for diabetic macular edema, they were 3.19 (1.55–6.59); 3.60 (1.58–8.22); 2.76 (1.18–6.44); and 3.01 (1.18–7.67), respectively. Odds were not significantly increased for other indicators. Discussion: Compared to individual indicators of poor diabetes control, risk of diabetic retinopathy and diabetic macular edema increased three to fourfold with a combination of these indicators. Targeting combined diabetes control indicators is important to reduce risk of diabetic retinopathy/diabetic macular edema. [ABSTRACT FROM AUTHOR]
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- 2017
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14. Assessment of the psychometric properties of the Chinese Impact of Vision Impairment questionnaire in a population-based study: findings from the Singapore Chinese Eye Study.
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Fenwick, Eva, Ong, Peng, Sabanayagam, Charumathi, Rees, Gwyn, Xie, Jing, Holloway, Edith, Cheng, Ching-Yu, Wong, Tien, Lim, Blanche, Tan, Pok, Lamoureux, Ecosse, Fenwick, Eva K, Ong, Peng Guan, Wong, Tien Y, Tan, Pok Chien, and Lamoureux, Ecosse L
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PSYCHOMETRICS , *QUESTIONNAIRES , *DISEASE prevalence , *VISION disorders , *RASCH models , *CHINESE people , *DISEASE risk factors , *DISEASES , *QUALITY of life , *ASIANS , *COMPARATIVE studies , *RESEARCH methodology , *MEDICAL cooperation , *MENTAL health , *PUBLIC health surveillance , *RESEARCH , *SICKNESS Impact Profile , *EVALUATION research , *PSYCHOLOGY ,RESEARCH evaluation - Abstract
Purpose: We investigated whether the Chinese impact of vision impairment (IVI) questionnaire is valid to generate reliable person estimates in a population-based sample.Methods: VRQoL was measured using the 32-item Chinese version of the IVI questionnaire in the Singapore Chinese Eye Study (2009-2011), a population-based study of the prevalence and risk factors for VI and eye diseases in Chinese Singaporeans. Rasch analysis was used to assess the Chinese IVI's response category functioning, precision, unidimensionality, targeting and differential item functioning. The ability of the Chinese IVI to discriminate participants along the spectrum of VI demonstrated criterion validity.Results: Of the 3353 participants, 27.2 % (n = 912) had VI (presenting visual acuity <6/12, better eye). Response categories were collapsed from six to four to resolve disordered thresholds. The Chinese IVI initially demonstrated multidimensionality and was split into three scales: 'Reading and Accessing Information'; 'Mobility and Independence'; and 'Emotional Well-being'. All three scales were unidimensional and demonstrated excellent range-based precision (all reliability coefficients 0.97), following removal of three misfitting items. Mean person measures decreased with worsening VI (e.g. Reading: none (7.50 logits); mild (6.99 logits); moderate (6.44 logits); and severe (3.01 logits) VI; p < 0.001).Conclusions: A three-dimensional 29-item Chinese IVI is a valid tool to assess the impact of VI on VRQoL in a large population-based sample, comprising over a quarter of participants with VI. The 28-item English IVI is also likely to be valid for use in population-based studies; however, this must be demonstrated empirically in future studies. [ABSTRACT FROM AUTHOR]- Published
- 2016
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15. Evaluation of item candidates for a diabetic retinopathy quality of life item bank.
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Fenwick, Eva, Pesudovs, Konrad, Khadka, Jyoti, Rees, Gwyn, Wong, Tien, and Lamoureux, Ecosse
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DIABETIC retinopathy , *QUALITY of life , *LITERATURE reviews , *HEALTH outcome assessment , *FOCUS groups , *EYE diseases , *OPHTHALMOLOGY , *COGNITION - Abstract
Purpose: We are developing an item bank assessing the impact of diabetic retinopathy (DR) on quality of life (QoL) using a rigorous multi-staged process combining qualitative and quantitative methods. We describe here the first two qualitative phases: content development and item evaluation. Methods: After a comprehensive literature review, items were generated from four sources: (1) 34 previously validated patient-reported outcome measures; (2) five published qualitative articles; (3) eight focus groups and 18 semi-structured interviews with 57 DR patients; and (4) seven semi-structured interviews with diabetes or ophthalmic experts. Items were then evaluated during 3 stages, namely binning (grouping) and winnowing (reduction) based on key criteria and panel consensus; development of item stems and response options; and pre-testing of items via cognitive interviews with patients. Results: The content development phase yielded 1,165 unique items across 7 QoL domains. After 3 sessions of binning and winnowing, items were reduced to a minimally representative set ( n = 312) across 9 domains of QoL: visual symptoms; ocular surface symptoms; activity limitation; mobility; emotional; health concerns; social; convenience; and economic. After 8 cognitive interviews, 42 items were amended resulting in a final set of 314 items. Conclusions: We have employed a systematic approach to develop items for a DR-specific QoL item bank. The psychometric properties of the nine QoL subscales will be assessed using Rasch analysis. The resulting validated item bank will allow clinicians and researchers to better understand the QoL impact of DR and DR therapies from the patient's perspective. [ABSTRACT FROM AUTHOR]
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- 2013
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16. The impact of diabetic retinopathy on quality of life: qualitative findings from an item bank development project.
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Fenwick EK, Pesudovs K, Khadka J, Dirani M, Rees G, Wong TY, Lamoureux EL, Fenwick, Eva K, Pesudovs, Konrad, Khadka, Jyoti, Dirani, Mohamed, Rees, Gwyn, Wong, Tien Y, and Lamoureux, Ecosse L
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Purpose: Assessing the efficacy of treatment modalities for diabetic retinopathy (DR) from the patient's perspective is restricted due to a lack of a comprehensive patient-reported outcome measure. We are developing a DR-specific quality of life (QoL) item bank, and we report here on the qualitative results from the first phase of this project.Methods: Eight focus groups and 18 semi-structured interviews were conducted with 57 patients with DR. The sessions were transcribed verbatim and iteratively analysed using the constant comparative method and NVIVO software.Results: Participants had a median age of 58 years (range 27-83 years). Twenty-seven (47%) participants had proliferative DR in the better eye, and 14 (25%) had clinically significant macular oedema. Nine QoL domains were identified, namely visual symptoms, ocular surface symptoms, vision-related activity limitation, mobility, emotional well-being, health concerns, convenience, social, and economic. Participants described many vision-related activity limitations, particularly under challenging lighting conditions; however, socioemotional issues were equally important. Participants felt frustrated due to their visual restrictions, concerned about further vision loss and had difficulty coping with this uncertainty. Restrictions on driving were pervasive, affecting transport, social life, relationships, responsibilities, work and independence.Conclusions: Patients with DR experience many socioemotional issues in addition to vision-related activity limitations. Data from this study will be used to generate data for a DR-specific QoL item bank. [ABSTRACT FROM AUTHOR]- Published
- 2012
17. The impact of diabetic retinopathy on quality of life: qualitative findings from an item bank development project.
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Fenwick, Eva, Pesudovs, Konrad, Khadka, Jyoti, Dirani, Mohamed, Rees, Gwyn, Wong, Tien, and Lamoureux, Ecosse
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QUALITY of life , *QUALITATIVE research , *HEALTH outcome assessment , *FOCUS groups , *SYMPTOMS , *WELL-being , *COMPARATIVE studies ,DIABETIC retinopathy treatment - Abstract
Purpose: Assessing the efficacy of treatment modalities for diabetic retinopathy (DR) from the patient's perspective is restricted due to a lack of a comprehensive patient-reported outcome measure. We are developing a DR-specific quality of life (QoL) item bank, and we report here on the qualitative results from the first phase of this project. Methods: Eight focus groups and 18 semi-structured interviews were conducted with 57 patients with DR. The sessions were transcribed verbatim and iteratively analysed using the constant comparative method and NVIVO software. Results: Participants had a median age of 58 years (range 27-83 years). Twenty-seven (47%) participants had proliferative DR in the better eye, and 14 (25%) had clinically significant macular oedema. Nine QoL domains were identified, namely visual symptoms, ocular surface symptoms, vision-related activity limitation, mobility, emotional well-being, health concerns, convenience, social, and economic. Participants described many vision-related activity limitations, particularly under challenging lighting conditions; however, socioemotional issues were equally important. Participants felt frustrated due to their visual restrictions, concerned about further vision loss and had difficulty coping with this uncertainty. Restrictions on driving were pervasive, affecting transport, social life, relationships, responsibilities, work and independence. Conclusions: Patients with DR experience many socioemotional issues in addition to vision-related activity limitations. Data from this study will be used to generate data for a DR-specific QoL item bank. [ABSTRACT FROM AUTHOR]
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- 2012
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18. Methodology and early findings of the Diabetes Management Project: a cohort study investigating the barriers to optimal diabetes care in diabetic patients with and without diabetic retinopathy.
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Lamoureux, Ecosse Luc, Fenwick, Eva, Xie, Jing, Mcauley, Annie, Nicolaou, Theona, Larizza, Melanie, Rees, Gwyn, Qureshi, Salmaan, Wong, Tien Yin, Benarous, Rehab, and Dirani, Mohamed
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DIABETIC retinopathy , *PEOPLE with diabetes , *COHORT analysis , *GLYCOSYLATED hemoglobin , *BLOOD pressure , *HEALTH outcome assessment - Abstract
A bstract Background: The Diabetes Management Project is investigating the clinical, behavioural and psychosocial barriers to optimal diabetes care in individuals with and without diabetic retinopathy. Design: Prospective cohort. Participants: Two hundred and twenty-three and 374 patients without and with diabetic retinopathy, respectively. Methods: All individuals underwent a comprehensive dilated eye test, anthropometric measurements, blood and urine samples, and psychosocial questionnaires. Main Outcome Measures: Good glycaemic control was defined as glycosylated haemoglobin < 7%, good blood pressure control as systolic and diastolic values ≤130 and 80 mmHg, respectively, and good diabetes control as glycosylated haemoglobin < 7% and blood pressure values ≤130 and 80 mmHg. Results: Four hundred and one males (65.4%) and 212 females (34.6%) aged 26-90 years (mean age ± standard deviation = 64.6 ± 11.6) were examined. The median glycosylated haemoglobin for all participants was 7.5% (interquartile range = 1.7%). Average systolic and diastolic blood pressure values were 139.7 mmHg (standard deviation = 18.8) and 92.7 mmHg (standard deviation = 30.9), respectively. Initial data analyses indicate that over two-thirds of participants with diabetes have poor glycaemic control, which was worse in those with diabetic retinopathy compared with those without (76.3% vs. 49.3%; P < 0.001). Blood pressure control was similar for those with and without diabetic retinopathy, with almost a third (28.5%) of the total sample having poor blood pressure control. Overall, those with diabetic retinopathy had poorer diabetes control than those without (24.3% vs. 13.7%; P = 0.002). Conclusions: Our findings substantiate the implementation of the Diabetes Management Project, developed to assess factors associated with suboptimal diabetes care. [ABSTRACT FROM AUTHOR]
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- 2012
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19. The relationship between visual function, duration and main causes of vision loss and falls in older people with low vision.
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Lamoureux, Ecosse, Gadgil, Sandeep, Pesudovs, Konrad, Keeffe, Jill, Fenwick, Eva, Dirani, Mohamed, Salonen, Satu, and Rees, Gwyn
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LOW vision , *VISION disorders , *OLDER people , *VISUAL acuity , *ACCIDENTAL falls in old age , *CROSS-sectional method - Abstract
Falls are an alarming health problem and a major cause of injury among the elderly. The healthcare cost associated with falls is considerable. Visual acuity has been found to be an independent risk factor for falls; however, the results are not unanimous. Moreover, other aspects of visual function such as visual field, contrast sensitivity and depth perception have not been adequately investigated in relation to falls. The aim of this study, therefore, was to determine the relationship between visual function, duration, and main causes of visual impairment, and falls in individuals with low vision. This was a cross-sectional study involving participants attending a public tertiary eye care hospital. Participants were mobile, aged 60 years or above, and had low vision (visual acuity >0.3 LogMAR in the better eye). Details about falls in the previous 12 months and other information were collected, and patients completed a questionnaire about activities of daily living. The duration and main causes of visual impairment, visual acuity, contrast sensitivity, depth perception, and visual field were assessed. Descriptive statistical analyses were performed to characterize the participants’ sociodemographic and clinical data. One hundred and twenty seven patients (53%; 67 males) with a mean age of 76.3 ± 8.3 years were recruited. Thirty seven percent of the participants ( n = 47) had mild, 50% ( n = 64) moderate and 13% ( n = 16) severe visual impairment (>0.3–0.5; >0.5–1.0; and >1.0 LogMAR respectively). The frequencies of single and multiple falls were 42.5% and 12.6% respectively. Visual acuity, contrast sensitivity, depth perception, visual field, main cause, and duration of visual impairment were not significantly associated with falls ( p > 0.05). In multiple regression analyses, physical inactivity remained the only variable independently associated with falls in all models except for visual field. Overall, visually impaired people were three times more likely to fall if they were physically inactive. Visual function, duration and main causes of visual impairment are not independently associated with falls in people with low vision. However, a significant relationship between non-participation in physical activity and falls was found. Further work is required to investigate the association between vision-related factors and falls in older people with visual impairment. [ABSTRACT FROM AUTHOR]
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- 2010
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20. An Evaluation of the 10-item Vision Core Measure 1 (VCM1) Scale (the Core Module of the Vision-Related Quality of Life scale) Using Rasch Analysis.
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Lamoureux, Ecosse L., Pesudovs, Konrad, Pallant, Julie F., Rees, Gwyn, Hassell, Jennifer B., Caudle, Lynda E., and Keeffe, Jill E.
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VISION disorders , *CATARACT , *EYE care , *PEOPLE with visual disabilities , *POPULATION , *PUBLIC health - Abstract
Purpose: To assess and re-engineer the Vision Core Measure 1 (VCM1) questionnaire in low vision (LV) and cataract participants using Rasch analysis. Methods: 295 participants drawn from a low vision clinic and 181 from a cataract surgery waiting list completed the 10-item VCM1. Unidimensionality, item fit to the model, response category performance, differential item functioning (DIF) and targeting of items to patients were assessed. Category collapsing and item removal were considered to improve the questionnaire. Results: The initial fit of the VCM1 (combined populations) to the Rasch model showed lack of fit (χ 2 = 83.3, df = 50, p = 0.002). There was evidence of DIF between the two populations which could not be resolved. Consequently, each population was assessed separately. Irrespective of the population, disordering of response category thresholds was evident. However, collapsing categories produced ordered thresholds and resulted in fit to the Rasch model for the LV (Total χ 2 = 41.6, df = 30; p = 0.08) and cataract population (Total χ 2 = 17.9, df = 20, p = 0.59). Overall, the VCM1 behaved as a unidimensional scale for each population and no item showed evidence of DIF. Item targeting to patients was however sub-optimal particularly for the cataract population. Conclusion: The VCM1 questionnaire could be improved by shortening the response scale, although different response categories are required for cataract and LV populations. Calibration of items also differed across populations. While the VCM1 performs well within the Rasch model, in line with its initial purpose, it requires the addition of items to satisfactorily target low vision and cataract populations. [ABSTRACT FROM AUTHOR]
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- 2008
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21. Assessing Participation in Daily Living and the Effectiveness of Rehabiliation in Age Related Macular Degeneration Patients Using the Impact of Vision Impairment Scale.
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Lamoureux, Ecosse L., Pallant, Julie F., Pesudovs, Konrad, Tennant, Alan, Rees, Gwyn, O'Connor, Patricia M., and Keeffe, Jill E.
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RETINAL degeneration , *VISION disorders , *RETINAL diseases , *ACTIVITIES of daily living , *LOW vision , *EVALUATION , *QUALITY of life - Abstract
Purpose: To assess if the Impact of Vision Impairment (IVI) is a valid instrument to measure participation in daily activities and rehabilitation in patients with age-related macular degeneration (AMD) and varying levels of visual impairment. Methods: Participants, recruited from a public eye hospital and low vision centers, completed the IVI questionnaire. The IVI and its three subscales were assessed for fit to the Rasch model. Unidimensionality, item fit, response category performance, and targeting of items to patients were assessed. Confirmatory factor analysis (CFA) was used to assess the three-factor model of the IVI in this sample of AMD patients. Results: 219 patients (mean ± SD age = 83.5 ± 7.4 yr) were recruited. Of these, 22%, 55% and 23% had mild (< 6/12-6/18), moderate (< 6/18-6/60) and severe (< 6/60) vision loss, respectively. The IVI total and three subscales displayed discrete thresholds indicating that the respondents understood the response categories. The IVI items fitted the scale and unidimensionality was established. Person separation reliability for the IVI score was substantial (0.94) indicating that the scale can discriminate between several groups of AMD patients. The IVI items were significantly targeted to the AMD patients with the means of the two distributions shown to be very close (0.0 and 0.1, respectively). Substantial targeting was also evident for the subscales. Poorer visual acuity was significantly associated (ANOVA; F (2, 216) = 23.4; p < 0.001) with greater restriction of participation suggesting that the IVI has substantial construct validity. CFA supported the IVI three-factor model which includes items from the "emotional well-being, "reading and accessing information" and "mobility and independence" subscales. Conclusions: Clinicians and researchers can reliably use the IVI to assess the impact on daily life and the effectiveness of clinical trials and rehabilitation interventions in patients with AMD across a range of vision loss. [ABSTRACT FROM AUTHOR]
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- 2008
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22. Flow regimes of Himalayan rivers of Nepal: nature and spatial patterns
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Hannah, David M., Kansakar, Sunil R., Gerrard, A.J., and Rees, Gwyn
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HYDROLOGIC cycle , *WATER pollution , *GROUNDWATER , *HYDROGEOLOGY - Abstract
Abstract: A large-scale perspective is provided upon the spatial distribution of river flow regimes across the Nepalese Himalaya by classifying long-term average monthly runoff data for 28 river basins. The classification methodology is shown to be a useful tool for identifying underlying spatial structure in flow regime shape (timing of peak) and magnitude (low, intermediate and high) in an extreme physical environment where hydrological patterns are complex and poorly known. Low, marked August peak regimes occur across far-western Nepal but also in some eastern basins, which have a short summer monsoon and snow- and ice-melt. Low, July–August peak regimes are found in the central to eastern High Mountains and High Himalaya and the eastern Middle Mountains where the summer monsoon arrives earliest, meltwaters contribute but topography limits precipitation amount. Low–intermediate, August–September peak regimes dominate the central Middle Mountains due to an extended summer monsoon and greater groundwater contributions. Intermediate–high magnitude regimes occur along the Middle Mountains–High Mountains boundary with July–August peaks in western–central areas and marked August peaks at higher elevations in eastern–central and eastern Nepal, reflecting differences in summer monsoon penetration. The practical implications of these results for assessment of water resources and prediction of runoff from ungauged basins are highlighted. [Copyright &y& Elsevier]
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- 2005
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23. Improving eye care in residential aged care facilities using the Residential Ocular Care (ROC) model: study protocol for a multicentered, prospective, customized, and cluster randomized controlled trial in Australia.
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Holloway, Edith E., Constantinou, Marios, Xie, Jing, Fenwick, Eva K., Finkelstein, Eric A., Man, Ryan E. K., Coote, Michael, Jackson, Jonathan, Rees, Gwyn, and Lamoureux, Ecosse L.
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EYE care , *ELDER care , *RANDOMIZED controlled trials , *CATARACT surgery , *HOME care of older people , *NURSING care facilities , *AGE distribution , *COST effectiveness , *EYE , *EYE examination , *HEALTH status indicators , *INTEGRATED health care delivery , *LONGITUDINAL method , *MEDICAL care costs , *MEDICAL cooperation , *OPHTHALMOLOGY , *RESEARCH , *TIME , *VISION , *SENIOR housing , *VISION disorders , *TREATMENT effectiveness , *DIAGNOSIS , *ECONOMICS ,TREATMENT of vision disorders - Abstract
Background: Older adults in residential aged care facilities have unnecessarily high levels of vision impairment (VI) which are largely treatable or correctable. However, no current comprehensive eye health service model exists in this setting in Australia. We aimed to determine the clinical, person-centered, and economic effectiveness of a novel eye care model, the Residential Ocular Care (ROC).Methods/design: This protocol describes a multicentered, prospective, randomized controlled trial. A total of 395 participants with distance vision < 6/12 (0.30 LogMAR) and/or near vision N8 (1.00 M) or worse will be recruited from 38 urban and rural aged care facilities across Victoria, Australia. Aged care facilities will be randomized (1:1) to one of two parallel groups. Participants in the ROC group will receive a comprehensive and tailored eye care pathway that includes, as necessary, refraction and spectacle provision, cataract surgery, low vision rehabilitation, and/or a referral to an ophthalmologist for funded treatment. Usual care participants will be referred for an evaluation to the eye care service associated with the facility or an eye care provider of their choice. The primary outcome will be presenting near and distance vision assessed at the two- and six-month follow-up visits, post baseline. Secondary outcomes will include vision-specific quality of life, mobility, falls, depression, and eye care utilization at two and six months. An incremental cost-effectiveness analysis will also be undertaken.Discussion: The ROC study is the first multicentered, prospective, customized, and cluster randomized controlled trial in Australia to determine the effectiveness of a comprehensive and tailored eye care model for people residing in aged care facilities. Results from this trial will assist health and social care planners in implementing similar innovative models of care for this growing segment of the population in Australia and elsewhere.Trial Registration: Australian and New Zealand Clinical Trials Registry, ACTRN12615000587505 . Registered on 4 June 2015 - retrospectively registered. [ABSTRACT FROM AUTHOR]- Published
- 2018
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24. Erratum to: The impact of diabetic retinopathy on quality of life: qualitative findings from an item bank development project.
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Fenwick, Eva, Pesudovs, Konrad, Khadka, Jyoti, Dirani, Mohamed, Rees, Gwyn, Wong, Tien, and Lamoureux, Ecosse
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PERIODICAL articles , *QUALITY of life , *QUALITATIVE research , *DIABETIC retinopathy , *MEDICAL research , *PUBLICATIONS , *PERIODICAL publishing - Published
- 2012
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