Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.
  • EQ-5D in skin conditions: an assessment of validity and responsiveness

    3 July 2018

    © 2014, The Author(s). Aims and objectives: This systematic literature review aims to assess the reliability, validity and responsiveness of three widely used generic preference-based measures of health-related quality of life (HRQL), i.e., EQ-5D, Health Utility Index 3 (HUI3) and SF-6D in patients with skin conditions. Methods: A systematic search was conducted to identify studies reporting health state utility values obtained using EQ-5D, SF-6D, or HUI3 alongside other HRQL measures or clinical indices for patients with skin conditions. Data on test-retest analysis for reliability, known group differences or correlation and regression analyses for validity, and change over time or responsiveness indices analysis were extracted and reviewed. Results: A total of 16 papers reporting EQ-5D utilities in people with skin conditions were included in the final review. No papers for SF-6D and HUI3 were found. Evidence of reliability was not found for any of these measures. The majority of studies included in the review (12 out of 16) examined patients with plaque psoriasis or psoriatic arthritis and the remaining four studies examined patients with either acne, hidradenitis suppurativa, hand eczema, or venous leg ulcers. The findings were generally positive in terms of performance of EQ-5D. Six studies showed that EQ-5D was able to reflect differences between severity groups and only one reported differences that were not statistically significant. Four studies found that EQ-5D detected differences between patients and the general population, and differences were statistically different for three of them. Further, moderate-to-strong correlation coefficients were found between EQ-5D and other skin-specific HRQL measures in four studies. Eight studies showed that EQ-5D was able to detect change in HRQL appropriately over time and the changes were statistically significant in seven studies. Conclusions: Overall, the validity and responsiveness of the EQ-5D was found to be good in people with skin diseases, especially plaque psoriasis or psoriatic arthritis. No evidence on SF-6D and HUI3 was available to enable any judgments to be made on their performance.

  • Comparison of health state utility values derived using time trade-off, rank and discrete choice data anchored on the full health-dead scale

    3 July 2018

    Recent years have seen increasing interest in the use of ordinal methods to elicit health state utility values as an alternative to conventional methods such as standard gamble and time trade-off (TTO). However, in order to use these ordinal methods to produce health state values for use in cost-effectiveness analysis using cost per quality adjusted life year (QALY) analysis, these values must be anchored on the full health-dead scale. The paper reports on two feasibility studies that use two approaches to anchor health state utility values derived from discrete choice data on the full health-dead scale: normalising using (1) the TTO value of the worst state and (2) the coefficient on the 'dead' dummy variable. Health state utility values obtained using rank and discrete choice data are compared to more commonly used TTO utility values for two condition-specific preference-based measures; asthma and overactive bladder. Ordinal methods were found to offer a promising alternative to conventional cardinal methods of standard gamble and TTO. There remains a large and important research agenda to address. © 2011 Springer-Verlag.

  • Fractional exhaled nitric oxide for the management of asthma in adults: A systematic review

    3 July 2018

    © ERS 2016. The aim of this review was to evaluate the clinical effectiveness of fractional exhaled nitric oxide (FeNO) measured in a clinical setting for the management of asthma in adults. 13 electronic databases were searched and studies were selected against predefined inclusion criteria. Quality assessment was conducted using QUADAS-2. Class effect meta-analyses were performed. Six studies were included. Despite high levels of heterogeneity in multiple study characteristics, exploratory class effect meta-analyses were conducted. Four studies reported a wider definition of exacerbation rates (major or severe exacerbation) with a pooled rate ratio of 0.80 (95% CI 0.63-1.02). Two studies reported rates of severe exacerbations (requiring oral corticosteroid use) with a pooled rate ratio of 0.89 (95% CI 0.43-1.72). Inhaled corticosteroid use was reported by four studies, with a pooled standardised mean difference of-0.24 (95% CI-0.56-0.07). No statistically significant differences for health-related quality of life or asthma control were found. FeNO guided management showed no statistically significant benefit in terms of severe exacerbations or inhaled corticosteroid use, but showed a statistically significant reduction in exacerbations of any severity. However, further research is warranted to clearly define which management protocols (including cut-off points) offer best efficacy and which patient groups would benefit the most.

  • Estimating a preference-based index for a 5-dimensional health state classification for asthma derived from the asthma quality of life questionnaire

    3 July 2018

    Background: This article presents a valuation study to estimate a preference-based index for a 5-dimensional health state classification for asthma (AQL-5D) derived from the Asthma Quality of Life Questionnaire (AQLQ). Methods: A sample of 307 members of the UK general population valued 99 asthma health states selected from the AQL-5D using the time tradeoff technique. Models were estimated to predict all possible 3125 health states defined by the AQL-5D, and the models were compared in terms of their ability to predict mean values for the 99 states. Results: Mean health state values ranged from 0.39 to 0.94 based on an average of 22 valuations per state. A main effects model estimated on mean health state values and adjusted for consistency had the best predictive ability (mean absolute error of 0.047 and only 9/98 states with errors >0.1) and the most logical consistency with levels of the AQL-5D. The low number of valuations per state may have resulted in unreliable estimates for the models. Preference-based condition specific measures are limited in their ability to make cross-disease comparisons. Conclusion: This is the first study to derive a conditionspecific preference-based measure from an existing measure of health-related quality of life in asthma for use in economic evaluation.

  • An exploratory study to test the impact on three "bolt-On" items to the EQ-5D

    3 July 2018

    © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Background Generic preference-based measures were criticized for being inappropriate in some conditions. One solution is to include "bolt-on" dimensions describing additional specific health problems. Objectives This study aimed to develop bolt-on dimensions to the EuroQol five-dimensional questionnaire (EQ-5D) and assess their impact on health state values. Methods Bolt-on dimensions were developed for vision problems, hearing problems, and tiredness. Each bolt-on dimension had three severity levels to match the EQ-5D. Three "core" EQ-5D states across a range of severity were selected, and each level of a bolt-on item was added, resulting in nine states in each condition. Health states with and without the bolt-on dimensions were valued by 300 members of the UK general public using time trade-off in face-to-face interviews, and mean health state values were compared using t tests. Regression analysis examined the impact of the bolt-on variants and the level of the bolt-on items after controlling for sociodemographic characteristics. Results Bolt-on dimensions had an impact on health state values of the EQ-5D; however, the size, direction, and significance of the impact depend on the severity of the core EQ-5D state and of the bolt-on dimension. Regression analysis demonstrated that after controlling for possible differences in sociodemographic characteristics between the groups, there were no significant differences in health state values between the three bolt-on dimensions but confirmed that the impact depended on the severity of the EQ-5D health state and the levels of bolt-on dimensions. Conclusions The impact of a bolt-on dimension on the EQ-5D depends on the core health state and the level of the bolt-on dimension. Further research in this area is encouraged.

  • EXOGEN Ultrasound Bone Healing System for Long Bone Fractures with Non-Union or Delayed Healing: A NICE Medical Technology Guidance

    3 July 2018

    © 2014, The Author(s). A routine part of the process for developing National Institute for Health and Care Excellence (NICE) medical technologies guidance is a submission of clinical and economic evidence by the technology manufacturer. The Birmingham and Brunel Consortium External Assessment Centre (EAC; a consortium of the University of Birmingham and Brunel University) independently appraised the submission on the EXOGEN bone healing system for long bone fractures with non-union or delayed healing. This article is an overview of the original evidence submitted, the EAC’s findings, and the final NICE guidance issued.

  • Effect of adding a sleep dimension to the EQ-5D descriptive system: A "bolt-on" experiment

    3 July 2018

    Background and Objective. The generic preference-based measures (GPBMs) of health have been widely used to obtain health utility scores for calculating quality-adjusted life-years (QALYs) for economic evaluations. It has been recognized that GPBMs may miss relevant or important dimensions of health for some specific medical conditions. The objective of this study is to explore the effect of extending the current EQ-5D descriptive system by adding a sleep dimension. Methods. A new instrument, EQ-5D+Sleep, is proposed by adding a sleep dimension to the EQ-5D. Based on an orthogonal design, 18 EQ-5D+Sleep states and EQ-5D states were selected and a valuation study was undertaken whereby 160 members of the generic public in South Yorkshire, UK, were interviewed using time tradeoff (TTO). Econometric models have been fitted to the data. Two null hypotheses were tested: 1) the coefficient for the sleep dimension is not significant; and 2) the inclusion of the sleep dimension has no impact on the way people value the original dimensions of EQ-5D. Results and Conclusions. The results support these two null hypotheses. There seems to be no benefit to adding a sleep dimension to the EQ-5D. Research is required to explore the method of adding dimensions to existing descriptive systems of health. © The Author(s) 2013.

  • Estimating a preference-based single index from the overactive bladder questionnaire

    3 July 2018

    Objectives: The aim of the study is to estimate a preference-based single index for calculating quality-adjusted life years for patients with overactive bladder (OAB), based on a survey of the UK general population using the 5-dimensional health classification system OAB-5D, derived from the validated Overactive Bladder Questionnaire (OAB-q). Methods: An interview valuation survey of members of public in the South Yorkshire, UK was undertaken using the time-trade-off method. Each respondent was randomly allocated to one of 14 blocks, and valued seven states each plus the "pits" state, so that a total of 99 states were valued. A number of multivariate regression models were estimated for predicting a total of 3125 health state values defined by the classification. Models were compared and selected using a set of criteria, including overall diagnosis by adjusted R-squared, the sign and significance of individual parameter estimates, the relative size of coefficients within a given dimension and predictive ability. Results: The mean model was recommended for use in economic evaluation. Conclusion: This will permit the cost-effectiveness of new interventions to be assessed in patients with OAB using existing and future OAB-q data sets. © 2008, International Society for Pharmacoeconomics and Outcomes Research (ISPOR).