Clk Lam

Are we making good use of our public resources? The false-positive rate of screening by fundus photography for diabetic macular oedema.

INTRODUCTIONnA large proportion of patients diagnosed with diabetic maculopathy using fundus photography and hence referred to specialist clinics following the current screening guidelines adopted in Hong Kong and United Kingdom are found to be false-positive, implying that they did not have macular oedema. This study aimed to evaluate the false-positive rate of diabetic maculopathy screening using the objective optical coherence tomography scan.nnnMETHODSnThis was a cross-sectional observational study. Consecutive diabetic patients from the Hong Kong West Cluster Diabetic Retinopathy Screening Programme with fundus photographs graded R1M1 were recruited between October 2011 and June 2013. Spectral-domain optical coherence tomography imaging was performed. Central macular thickness of ≥300 μm and/or the presence of optical coherence tomography signs of diabetic macular oedema were used to define the presence of diabetic macular oedema. Patients with conditions other than diabetes that might affect macular thickness were excluded. The mean central macular thickness in various subgroups of R1M1 patients was calculated and the proportion of subjects with central macular thickness of ≥300 μm was used to assess the false-positive rate of this screening strategy.nnnRESULTSnA total of 491 patients were recruited during the study period. Of the 352 who were eligible for analysis, 44.0%, 17.0%, and 38.9% were graded as M1 due to the presence of foveal haemorrhages, exudates, or haemorrhages and exudates, respectively. The mean (±standard deviation) central macular thickness was 265.1±55.4 μm. Only 13.4% (95% confidence interval, 9.8%-17.0%) of eyes had a central macular thickness of ≥300 μm, and 42.9% (95% confidence interval, 37.7%-48.1%) of eyes had at least one optical coherence tomography sign of diabetic macular oedema. For patients with retinal haemorrhages only, 9.0% (95% confidence interval, 4.5%-13.5%) had a central macular thickness of ≥300 μm; 23.2% (95% confidence interval, 16.6%-29.9%) had at least one optical coherence tomography sign of diabetic macular oedema. The false-positive rate of the current screening strategy for diabetic macular oedema was 86.6%.nnnCONCLUSIONnThe high false-positive rate of the current diabetic macular oedema screening adopted by the United Kingdom and Hong Kong may lead to unnecessary psychological stress for patients and place a financial burden on the health care system. A better way of screening is urgently needed. Performing additional spectral-domain optical coherence tomography scans on selected patients fulfils this need.

Changes in health-related quality of life among adults from low-income families in Hong Kong

Background: The aim of this study is to examine the interest for relation between quality of life (QOL) and well being of an implementation of a program of physical activity, with patients of Multiple Sclerosis (MS). Methods: This is a correlation study. The study includes 27 patients with MS, mean age 44 years, 58,3 % women, 37,5% currently married, 67% retired, mean school level of 12,5 years. We use the questionnaire and the Multiple Sclerosis Quality of Life scale (MSQol-54) and sub scale psychological well-being (PWB) of Mental Health Inventory The program consists of an intervention to promote physical activity (IPPA) in a group of eight people, in once a week sessions of 90 minutes, during seven weeks. We analyze the results through the Spearman correlation tests between the dimensions of MSQOL-54 and Well-being. Findings: The Results the correlations between PWB and the domains of MSQOL-54 before application of IPPA and the end of the implementation of IPPA, showed that there were statistically significant correlations between all variables. Discussion: In this study, suggests that IPPA can play an important in the relation between the QOL and PWB of these patients.23rd Annual Conference of the International Society for Quality of Life Research Springer International Publishing Switzerland 2016 Cutting edge research plenary (1) Consensus-based standards and criteria for evaluating the content validity of patient-reported outcome measures: a COSMIN Delphi study Caroline B. Terwee, PhD, VU University Medical Center, Amsterdam, Netherlands; Cecilia A. Prinsen, PhD, VU University Medical Center, Amsterdam, Netherlands; Alessandro Chiarotto, MS (PhD Student), VU University Medical Center, Amsterdam, Netherlands; Marjan J. Westerman, PhD, VU University, Amsterdam, Netherlands; Henrica de Vet, PhD, VU University Medical Center, Amsterdam, Netherlands; Donald Patrick, PhD, University of Washington, Seattle, WA, United States; Jordi Alonso, PhD, IMIM (Hospital del Mar Medical Research Institute), Barcelona; CIBER en Epidemiologı́a y Salud Pública (CIBERESP), Madrid; Pompeu Fabra University (UPF), Barcelona, Spain; Lex M. Bouter, PhD, VU University Medical Center, Amsterdam, Netherlands; Lidwine B. Mokkink, PhD, VU University Medical Center, Amsterdam, Netherlands Aims: Content validity is considered to be the most important measurement property of a Patient-Reported Outcome Measure (PROM). Guidelines to evaluate content validity of PROMs are emerging, but there is a lack of a consensus-based checklist for assessing the quality of content validity studies. The current COSMIN standards only consider whether certain things have been done, but not how they were done, and the quality of the PROM development is not taken into account. Also consensus-based criteria for what constitutes good content validity of PROMs are lacking. The aim of this study was to reach consensus on standards and criteria for evaluating the content validity of PROMs. Standards refer to design requirements of studies and are used to evaluate the quality of studies on PROM development and content validity. Criteria refer to what constitutes good content validity and are used to evaluate the content validity of the PROM itself. Methods: A Delphi consensus study was performed in three email rounds among COSMIN users, authors of systematic reviews of PROMs and (methodological) papers on content validity. Potential standards and criteria were extracted from a systematic literature search. Participants were asked to rate the relevance of each proposed standard and criterion on a 5-point scale. In addition, they were invited to make comments. RESULTS: 158 experts from 21 countries participated. Consensus was reached on 28 standards for evaluating the quality of PROM development studies and 37 standards for evaluating the quality of studies evaluating the content validity of a PROM. Consensus was reached on 9 criteria for evaluating the content validity (i.e. relevance, comprehensiveness, and comprehensibility) of the PROM itself. The standards and criteria were pilot tested in a systematic review evaluating the content validity of PROMs for low back pain patients and slight adaptations were made. A user manual was developed with explanations and examples on how each item should be completed. Conclusions: The new COSMIN standards and criteria can be used in systematic reviews of PROMs to evaluate the content validity of PROMs for a given context and population in a standardized and transparent way. (2) Telling the interpretation story: the case for strong anchors and multiple methods Cheryl D. Coon, PhD, Outcometrix, Tucson, AZ, United States Aims: The patient-reported outcome (PRO) field continues to debate best practices for establishing thresholds for interpreting change on instruments. To gain insight into the value of common methods for determining thresholds, this simulation study intended to generate data with known properties against which the methods could be considered. Methods: Data were generated based on a t-score metric with half of the 1000-simulee sample (i.e., placebo) experiencing no change (centered at 0) and half (i.e., treatment) experiencing a 0.5standard deviation improvement (centered at 5). Five-category anchors were generated from the same distributions, with correlations between the PRO scores and the anchors ranging from 0.3 to 0.8. The ‘‘true’’ threshold for improvement was set at a score of 5. Methods evaluated included classification statistics (i.e., sensitivity, specificity, positive predictive value, negative predictive value), discriminant analysis, and regression. Results: Results for a correlation of 0.3 were difficult to interpret, which is consistent with the literature that proposes the correlation between the anchor and the PRO instrument be stronger than 0.3. The thresholds that might be considered from the 0.3 correlation results were deflated, which risks setting the bar for interpretation too low. A correlation of 0.5 produced more easily interpretable results, with thresholds ranging from approximately 4–9, depending on the method. A correlation of 0.8 produced more distinct inflection points, with thresholds ranging from approximately 4–8. Even with the strongest correlation, the PRO scores produced false positives and false negatives. Conclusions: This simulation study 123 Qual Life Res (2016) 25:1–196 DOI 10.1007/s11136-016-1390-7

The influence of incremental cost-effectiveness ratio on Health Technology Assessment of Cancer Screening in Hong Kong

ESMDM MEETING ABSTRACTS E449 Canada and James OMahony, Trinity College Dublin, Dublin, Ireland Late-breaking abstract for 2016 CADTH Symposium Mike Paulden, James O’Mahony, Christopher McCabe, 1. Department of Emergency Medicine, University of Alberta, Canada 2. Trinity College Dublin, Ireland Purpose: Net health benefit (NHB) and net monetary benefit (NMB) are alternatives to using incremental cost-effectiveness ratios (ICERs) in the economic evaluation of health technologies. Conventionally, NHB and NMB are regarded as equivalent, and the cost-effectiveness threshold (λ) is used to assign weights to health gains and losses when specifying NMB. We demonstrate important differences between these measures, and argue that NMB is preferred when making value-based reimbursement decisions. We further show that using λ to assign weights when specifying NMB is theoretically flawed. Method(s): We consider the circumstances in which NHB and NMB are equivalent. We then build upon the foundations of the ‘social decision making’ (SDM) perspective to allow for a theoretical consideration of the weights that ought to be assigned when specifying NMB. Result(s): We demonstrate that NHB and NMB are not equivalent if λ changes over time or is uncertain. Given this non-equivalence, decision makers must decide which measure to use. For value-based reimbursement decisions, NMB is preferred because it allows for differential weights to be assigned to health outcomes where desired. Under a SDM perspective, these weights ought to be informed by society’s valuation of health in each time period. Since, in future periods, these valuations may differ from those implied by λ, using λ to determine these weights is theoretically flawed. Conclusion(s): Our findings have important implications for value-based reimbursement decisions. It is time to move on from using NHB and instead adopt a measure of NMB that appropriately reflects society’s valuation of health. PS1-3 THE COST-EFFECTIVENESS OF POINT-OF-CARE TROPONIN TESTING TO DIAGNOSE ACUTE CORONARY SYNDROME IN PRIMARY CARE Applied Health Economics (AHE) Michelle M.A. Kip, MSc., Hendrik Koffijberg, PhD, Marco J. Moesker, MSc., Maarten J. IJzerman, PhD and Ron Kusters, PhD, University of Twente, Enschede, Netherlands