SF-6D Utility Research Articles

Mapping the disease-specific LupusQoL to the SF-6D.

To derive a mapping algorithm to predict SF-6D utility scores from the non-preference-based LupusQoL and test the performance of the developed algorithm on a separate independent validation data set. LupusQoL and SF-6D data were collected from 320 patients with systemic lupus erythematosus (SLE) attending routine rheumatology outpatient appointments at seven centres in the UK. Ordinary least squares (OLS) regression was used to estimate models of increasing complexity in order to predict individuals' SF-6D utility scores from their responses to the LupusQoL questionnaire. Model performance was judged on predictive ability through the size and pattern of prediction errors generated. The performance of the selected model was externally validated on an independent data set containing 113 female SLE patients who had again completed both the LupusQoL and SF-36 questionnaires. Four of the eight LupusQoL domains (physical health, pain, emotional health, and fatigue) were selected as dependent variables in the final model. Overall model fit was good, with R(2) 0.7219, MAE 0.0557, and RMSE 0.0706 when applied to the estimation data set, and R(2) 0.7431, MAE 0.0528, and RMSE 0.0663 when applied to the validation sample. This study provides a method by which health state utility values can be estimated from patient responses to the non-preference-based LupusQoL, generalisable beyond the data set upon which it was estimated. Despite concerns over the use of OLS to develop mapping algorithms, we find this method to be suitable in this case due to the normality of the SF-6D data.

Health related quality of life in patients with bladder cancer: a cross-sectional survey and validation study of the Hungarian version of the Bladder Cancer Index.

Health-related quality of life (HRQoL) is an important outcome in oncology care although an underexplored area in bladder cancer (BC). Our aims were to assess HRQoL of patients with BC, analyse relationships between diverse HRQoL measures and validate the Hungarian version of the Bladder Cancer Index (BCI) questionnaire. A cross-sectional survey was performed among patients with BC (N = 151). Validated Hungarian versions of the FACT-Bl, SF-36 and EQ-5D were applied and SF-6D was derived. Psychometric analysis of the Hungarian BCI was performed. Pearson correlations between the five measures were analysed. Deterioration in SF-36 Physical Functioning was detected among patients aged 45-64 years. The EQ-5D score did not differ significantly from the age-matched population norm. Correlations between the FACT-Bl, EQ-5D and SF-6D utility measures were strong (r > 0.6). Cronbach alpha coefficients of the Hungarian BCI ranged from 0.75 to 0.97 and factor analysis confirmed that data fit to the six predefined subdomains. Test-retest correlations (reliability, N = 50) ranged from 0.67 to 0.87 and interscale correlations between urinary, bowel and sexual BCI domains were weak or moderate (r = 0.29 to 0.49). Convergent validity revealed a stronger correlation with FACT-Bl (r = 0.126 to 0.719) than with generic health state scores (r = 0.096 to 0.584). Results of divergent validity of the Hungarian BCI by treatment groups by Kruskal Wallis test were promising although limited by low sample sizes in cystectomy subgroups. Generic health state measures have limited capacity to capture HRQoL impact of BC. Validity tests yielded favourable results for the Hungarian BCI. Mapping studies to estimate utility scores from FACT-Bl are encouraged but less recommendable with the BCI.

Health-related quality of life in women and men with type 2 diabetes: a comparison across treatment groups

AimThis study compares health-related quality of life (HRQL) in patients with type 2 diabetes (T2DM) across treatment groups and explores gender differences. MethodsFour regional surveys (KORA, CARLA, SHIP, DHS) and a national survey (GNHIES98) were pooled at individual level. HRQL was assessed with the SF-12/-36v1. Linear regression models were used to assess the effect of T2DM by treatment type (no medication; oral; oral/insulin combination; insulin) on the physical (PCS-12) and mental summary score (MCS-12) and the SF-6D, controlling for age, sex, study and covariates. We also performed an explanatory analysis of single items. ResultsPCS-12 scores and treatment type were associated (P-value 0.006), with lowest values for insulin treatment (–4.44 vs. oral; –4.41 vs. combination). MCS-12 scores were associated with treatment type and gender (P-value <0.012), with lower scores for women undergoing oral (–4.25 vs. men) and combination treatment (–6.99 vs. men). Similar results were observed for SF-6D utilities and single items, related to mental health, social functioning, vitality and role limitation (emotional). Comorbidities were predictors of lower PCS-12 and SF-6D scores. ConclusionsT2DM treatment impacts differently on physical and mental HRQL and on women and men. Further studies of gender-specific perceptions of T2DM treatment regimens are needed.

Mapping between the Roland Morris Questionnaire and Generic Preference-Based Measures

ObjectivesThe Roland Morris Questionnaire (RMQ) is a widely used health status measure for low back pain (LBP). It is not preference-based, and there are currently no established algorithms for mapping between the RMQ and preference-based health-related quality-of-life measures. Using data from randomized controlled trials of treatment for LBP, we sought to develop algorithms for mapping between RMQ scores and health utilities derived using either the EuroQol five-dimensional questionnaire (EQ-5D) or the six-dimensional health state short form (derived from Medical Outcomes Study 36-Item Short-Form Health Survey) (SF-6D). MethodsThis study is based on data from the Back Skills Training Trial in which data were collected from 701 patients at baseline and subsequently at 3, 6, and 12 months postrandomization using a range of outcome measures, including the RMQ, the EQ-5D, and the Short Form 12 item Health Survey (SF-12) (from which SF-6D utilities can be derived). We used baseline trial data to estimate models using both direct and response mapping approaches to predict EQ-5D and SF-6D health utilities and dimension responses. A multistage model selection process was used to assess the predictive accuracy of the models. We then explored different techniques and mapping models that made use of repeated follow-up observations in the data. The estimated mapping algorithms were validated using external data from the UK Back Pain Exercise and Manipulation trial. ResultsA number of models were developed that accurately predict health utilities in this context. The best performing model for RMQ to EQ-5D mapping was a beta regression with Bayesian quasi-likelihood estimation that included 24 dummy variables for RMQ responses, age, and sex as covariates (mean squared error 0.0380) based on repeated data. The model selected for RMQ to SF-6D mapping was a finite mixture model that included the overall RMQ score, age, sex, RMQ score squared, age squared, and an interaction term for age and RMQ score as covariates (mean squared error 0.0114) based on repeated data. ConclusionsIt is possible to reasonably predict EQ-5D and SF-6D health utilities from RMQ scores and responses using regression methods. Our regression equations provide an empirical basis for estimating health utilities when EQ-5D or SF-6D data are not available. They can be used to inform future economic evaluations of interventions targeting LBP.

Comparing and explaining differences in the magnitude, content, and sensitivity of utilities predicted by the EQ-5D, SF-6D, HUI 3, 15D, QWB, and AQoL-8D multiattribute utility instruments.

Cost utility analysis permits the comparison of disparate health services by measuring outcomes in comparable units, namely, quality-adjusted life-years, which equal life-years times the utility of the health state. However, comparability is compromised when different utility instruments predict different utilities for the same health state. The present paper measures the extent of, and reason for, differences between the utilities predicted by the EQ-5D-5L, SF-6D, HUI 3, 15D, QWB, and AQoL-8D. Data were obtained from patients in seven disease areas and members of the healthy public in six countries. Differences between public and patient utilities were estimated using each of the instruments. To explain discrepancies between the estimates, the measurement scales and content of the instruments were compared. The sensitivity of instruments to independently measured health dimensions was measured in pairwise comparisons of all combinations of the instruments. The difference between public and patient utilities varied with the choice of instrument by more than 50% for every disease group and in four of the seven groups by more than 100%. Discrepancies were associated with differences in both the instrument content and their measurement scales. Pairwise comparisons of instruments found that variation in the sensitivity to physical and psychosocial dimensions of health closely reflected the items in the instrument's descriptive systems. Results indicate that instruments measure related but different constructs. They imply that commonly used instruments systematically discriminate against some classes of services, most notably mental health services. Differences in the instrument scales imply the need for transformations between the instruments to increase the comparability of measurement.

Health-related quality of life after myocardial infarction, does choice of method make a difference?

Objectives. The aim of this study was to compare health-related quality of life (HRQoL) scores obtained from the instrument Short Form (SF)-36 through the so-called SF-6D utilities, and those obtained from 15D, in patients with ST-elevation myocardial infarction (STEMI), and to evaluate the consequences in estimation of quality adjusted life years (QALYs). Design. This was a sub-study of the Norwegian District Treatment of STEMI, in which patients with STEMI treated with tenecteplase, were randomized to early angioplasty or standard management (n = 266). HRQoL data were collected at all visits (0, 1, 3, 7 and 12 months). All patients with complete data were included (n = 248). Results. The score range was 0.33–1.0 for SF-6D and 0.49–1.0 for 15D. Mean utility scores from 15D were higher and had different distribution compared to scores from SF-6D. Mean QALY for the whole group was higher using 15D than SF-6D (0.89 vs. 0.77). The incremental number of QALYs with early angioplasty compared to standard treatment was 0.005 (95% CI: − 0.018 to 0.028) using SF-6D, and 0.004 (95% CI: − 0.010 to 0.018) using the 15D instrument. Conclusions. Choice of instrument may influence HRQoL scores, but not necessarily the gain in QALYs.

THU0433 A QALY is not A Qaly... with Eq-5D, You Have 70% More QALYS Gained than with SF-6D for the Same Treatment in Early Arthritis: Results of the ESPOIR Cohort

BackgroundThe explosion of drug development for rheumatoid arthritis and the revolution of early aggressive therapy for the disease have fuelled the search for better approaches to establish cost-effectiveness in early...

THU0432 Impact of Comorbidities on Measuring Indirect Utility by the SF-6D or the EQ-5D in Rheumatoid Arthritis: an Analysis of 962 Patients Enrolled in Comedra

BackgroundMany patients with rheumatoid arthritis (RA) have several chronic co-occuring disorders (comorbidities). There is an inverse relationship between comorbidy and health-related quality of life (HRQoL). Because indirect utility measurement involves...

Chronic stable angina is associated with lower health-related quality of life: evidence from Chinese patients.

ObjectivesTo compare health-related quality of life (HRQoL) between patients with stable angina and the general population in China and to examine factors associated with HRQoL among patients with stable angina.MethodsA cross-sectional HRQoL survey of stable angina patients recruited from 4 hospitals (n = 411) and the general population recruited from 3 Physical Examination Centers (n = 549) was conducted from July to December, 2011 in two large cities, Tianjin and Chengdu. HRQoL was assessed using the EQ-5D, EQ-VAS, and SF-6D instruments. The health status specific to patients with stable angina was assessed using the Seattle Angina Questionnaire (SAQ). Information on socio-demographic, clinical, and lifestyle factors were also collected. Nested regressions were performed to explore how these factors were associated with HRQoL in patients with stable angina.ResultsCompared with the general population (44.2±10 years, 49.9% females), stable angina patients (68.1±12 years, 50.4% females) had significantly lower HRQoL scores in EQ-5D utility index (0.75±0.19 vs. 0.90±0.20, p<0.05), SF-6D utility index (0.68±0.12 vs. 0.85±0.11, p<0.05), and EQ-VAS (71.2±12.3 vs. 83.9±10.9, p<0.05). The differences remained (−0.05 for EQ-5D, −9.27 for EQ-VAS and −0.13 for SF-6D) after controlling for socio-economic characteristics. SAQ scores showed that stable angina patients experienced impaired disease-specific health status, especially in angina stability (40.5±34.6). Nested regressions indicated stable angina-specific health status explained most of the variation in HRQoL, among which disease perception, physical limitation, and angina stability were the strongest predictors. More physical exercise and better sleep were positively related with HRQoL.ConclusionsCompared to the general population, stable angina patients were associated with lower HRQoL and lower health utility scores, which were largely impacted by clinical symptoms. Further studies are needed to characterize the influence of geographic and cultural factors on the variations of health-related utility in stable angina patients.

Evaluation of a structured goal planning and tailored follow-up programme in rehabilitation for patients with rheumatic diseases: protocol for a pragmatic, stepped-wedge cluster randomized trial.

BackgroundComprehensive rehabilitation, involving health professionals from various disciplines, is widely used as an adjunct to pharmacological and surgical treatment in people with rheumatic diseases. However, the evidence for the clinical- and cost-effectiveness of such interventions is limited, and the majority of those who receive rehabilitation are back to their initial health status six to 12 months after discharge.Methods/designTo evaluate the goal attainment, health effects and cost-effectiveness of a new rehabilitation programme compared to current traditional rehabilitation programmes for people with rheumatic diseases, a stepped-wedge cluster randomized trial will be performed. Patients admitted for rehabilitation at six centres in the south-eastern part of Norway will be invited to participate. In the trial, six participating centres will switch from a control (current rehabilitation programme) to an intervention phase (the new rehabilitation programme) in a randomized order. Supported by recent research, the new programme will be a supplement to the existing programme at each centre, and will comprise four elements designed to enhance and support lifestyle changes introduced in the rehabilitation period: structured goal-planning, motivational interviewing, a self-help booklet and four follow-up telephone calls during the first five months following discharge. The primary outcome will be health-related quality of life and goal attainment, as measured by the Patient Generated Index directly before and after the rehabilitation stay, as well as after six and 12 months. Secondary outcomes will include self-reported pain, fatigue, a global assessment of disease activity and motivation for change (measured on 11-point numeric ratings scales), health-related quality of life as measured by the Short Form 36 Health Survey (SF-36) and utility assessed by the SF6D utility index.The main analysis will be on an intention to treat basis and will assess the clinical- and cost-effectiveness of the structured goal planning and tailored follow-up rehabilitation programme for patients with rheumatic diseases.DiscussionThe findings will constitute an important contribution to more cost-effective- and evidence-based rehabilitation services for people with rheumatic diseases.Trial registrationISRCTN91433175.

Exploring psychometric properties of the SF-6D, a preference-based health-related quality of life measure, in the context of spinal cord injury

The validity of the SF-6D, a preference-based measure of health-related quality of life, is not well explored in the context of spinal cord injury (SCI). The aim of this analysis was to assess appropriate measurement properties of the SF-6D in a sample of individuals living with SCI. Longitudinal data from the Rick Hansen Spinal Cord Injury Registry were used. Responses to the 36-item short-form health survey were transformed into SF-6D utility scores. We investigated practicality, floor and ceiling effects, and responsiveness to change. Responsiveness to change was explored using three different anchors that reflected changes in self-reported health, functional independence, and life satisfaction. Discriminative validity was assessed by ten a priori defined hypotheses, with a distinction made between 'strong' and 'weak' hypotheses. Three hundred and fifty-eight individuals with SCI were included in this analysis. Practicality was deemed acceptable based on a completion rate of 94%. The SF-6D showed low responsiveness to detect important health changes over time, and differences in responsiveness were found between individuals with paraplegia and tetraplegia. All five strong hypotheses and three weak hypotheses were confirmed. The SF-6D demonstrated good practicality and discriminative validity in this sample. The failure to detect self-reported and clinically important health changes requires further consideration. Comparative performance of the SF-6D (i.e., how the SF-6D performs against other preference-based measures) is unknown in the SCI context and requires further research.

Sacroiliac joint pain: burden of disease.

ObjectivesThe sacroiliac joint (SIJ) is an important and significant cause of low back pain. We sought to quantify the burden of disease attributable to the SIJ.MethodsThe authors compared EuroQol 5D (EQ-5D) and Short Form (SF)-36-based health state utility values derived from the preoperative evaluation of patients with chronic SIJ pain participating in two prospective clinical trials of minimally invasive SIJ fusion versus patients participating in a nationally representative USA cross-sectional survey (National Health Measurement Study [NHMS]). Comparative analyses controlled for age, sex, and oversampling in NHMS. A utility percentile for each SIJ subject was calculated using NHMS as a reference cohort. Finally, SIJ health state utilities were compared with utilities for common medical conditions that were published in a national utility registry.ResultsSIJ patients (number [n]=198) had mean SF-6D and EQ-5D utility scores of 0.51 and 0.44, respectively. Values were significantly depressed (0.28 points for the SF-6D utility score and 0.43 points for EQ-5D; both P<0.0001) compared to NHMS controls. SIJ patients were in the lowest deciles for utility compared to the NHMS controls. The SIJ utility values were worse than those of many common, major medical conditions, and similar to those of other common preoperative orthopedic conditions.ConclusionPatients with SIJ pain presenting for minimally invasive surgical care have marked impairment in quality of life that is worse than in many chronic health conditions, and this is similar to other orthopedic conditions that are commonly treated surgically. SIJ utility values are in the lowest two deciles when compared to control populations.

SF-6D Portuguese population norms

Population-based norms are important because they provide benchmarks that allow the interpretation of subgroups of population health, comparisons between studies, information on health inequalities and support for health-care interventions. The SF-6D is a preference-based measure of health, the use of which has been increasing throughout the world. Other countries have provided population norms for the SF-6D. To date, SF-6D population norms for Portugal do not exist. This study therefore aimed to derive SF-6D Portuguese population norms. A representative sample of the Portuguese general public (n = 1,500) was used in a telephone-based interview. The SF-36v2 was applied and the Portuguese SF-6D value set was used to obtain the SF-6D index. Descriptive and inferential data analyses were applied to sociodemographic variables, the dimensions of the SF-6D and the SF-6D index. Health index scores of the target population and selected subpopulations were estimated using domain estimation techniques when necessary. SF-6D utility scores decline with increasing age. Women, widowed individuals and individuals with low educational attainment report lower levels of SF-6D utility scores than men, those with a high educational attainment and those who are single. This study reports Portuguese population norms measured using the SF-6D based on a national representative sample. These results can be used as reference data to inform policy.

Use of generic and condition-specific measures of health-related quality of life in NICE decision-making: a systematic review, statistical modelling and survey

The National Institute for Health and Care Excellence recommends the use of generic preference-based measures (GPBMs) of health for its Health Technology Assessments (HTAs). However, these data may not be available or appropriate for all health conditions. To determine whether GPBMs are appropriate for some key conditions and to explore alternative methods of utility estimation when data from GPBMs are unavailable or inappropriate. The project was conducted in three stages: (1) A systematic review of the psychometric properties of three commonly used GPBMs [EQ-5D, SF-6D and Health Utilities Index Mark 3 (HUI3)] in four broadly defined conditions: visual impairment, hearing impairment, cancer and skin conditions. (2) Potential modelling approaches to 'map' EQ-5D values from condition-specific and clinical measures of health [European Organisation for Research and Treatment of Cancer Quality-of-life Questionnaire Core 30 (EORTC QLQ-C30) and Functional Assessment of Cancer Therapy - General Scale (FACT-G)] are compared for predictive ability and goodness of fit using two separate data sets. (3) Three potential extensions to the EQ-5D are developed as 'bolt-on' items relating to hearing, tiredness and vision. They are valued using the time trade-off method. A second valuation study is conducted to fully value the EQ-5D with and without the vision bolt-on item in an additional sample of 300 people. The valuation surveys were conducted using face-to-face interviews in the respondents' homes. Two representative samples of the UK general population from Yorkshire (n=600). None. Comparisons of EQ-5D, SF-6D and HUI3 in four conditions with various generic and condition-specific measures. Mapping functions were estimated between EORTC QLQ-C30 and FACT-G with EQ-5D. Three bolt-ons to the EQ-5D were developed: EQ + hearing/vision/tiredness. A full valuation study was conducted for the EQ + vision. (1) EQ-5D was valid and responsive for skin conditions and most cancers; in vision, its performance varied according to aetiology; and performance was poor for hearing impairments. The HUI3 performed well for hearing and vision disorders. It also performed well in cancers although evidence was limited and there was no evidence in skin conditions. There were limited data for SF-6D in all four conditions and limited evidence on reliability of all instruments. (2) Mapping algorithms were estimated to predict EQ-5D values from alternative cancer-specific measures of health. Response mapping using all the domain scores was the best performing model for the EORTC QLQ-C30. In an exploratory analysis, a limited dependent variable mixture model performed better than an equivalent linear model. In the full analysis for the FACT-G, linear regression using ordinary least squares gave the best predictions followed by the tobit model. (3) The exploratory valuation study found that bolt-on items for vision, hearing and tiredness had a significant impact on values of the health states, but the direction and magnitude of differences depended on the severity of the health state. The vision bolt-on item had a statistically significant impact on EQ-5D health state values and a full valuation model was estimated. EQ-5D performs well in studies of cancer and skin conditions. Mapping techniques provide a solution to predict EQ-5D values where EQ-5D has not been administered. For conditions where EQ-5D was found to be inappropriate, including some vision disorders and for hearing, bolt-ons provide a promising solution. More primary research into the psychometric properties of the generic preference-based measures is required, particularly in cancer and for the assessment of reliability. Further research is needed for the development and valuation of bolt-ons to EQ-5D. This project was funded by the UK Medical Research Council (MRC) as part of the MRC-NIHR methodology research programme (reference G0901486) and will be published in full in Health Technology Assessment; Vol. 18, No. 9. See the NIHR Journals Library website for further project information.

A cost-effectiveness analysis of a telephone-linked care intervention for individuals with Type 2 diabetes

AimTo assess the cost-effectiveness of an automated telephone-linked care intervention, Australian TLC Diabetes, delivered over 6 months to patients with established Type 2 diabetes mellitus and high glycated haemoglobin level, compared to usual care. MethodsA Markov model was designed to synthesize data from a randomized controlled trial of TLC Diabetes (n=120) and other published evidence. The 5-year model consisted of three health states related to glycaemic control: ‘sub-optimal’ HbA1c ≥58mmol/mol (7.5%); ‘average’ ≥48–57mmol/mol (6.5–7.4%) and ‘optimal’ <48mmol/mol (6.5%) and a fourth state ‘all-cause death’. Key outcomes of the model include discounted health system costs and quality-adjusted life years (QALYS) using SF-6D utility weights. Univariate and probabilistic sensitivity analyses were undertaken. ResultsAnnual medication costs for the intervention group were lower than usual care [Intervention: £1076 (95%CI: £947, £1206) versus usual care £1271 (95%CI: £1115, £1428) p=0.052]. The estimated mean cost for intervention group participants over five years, including the intervention cost, was £17,152 versus £17,835 for the usual care group. The corresponding mean QALYs were 3.381 (SD 0.40) for the intervention group and 3.377 (SD 0.41) for the usual care group. Results were sensitive to the model duration, utility values and medication costs. ConclusionThe Australian TLC Diabetes intervention was a low-cost investment for individuals with established diabetes and may result in medication cost-savings to the health system. Although QALYs were similar between groups, other benefits arising from the intervention should also be considered when determining the overall value of this strategy.

EQ-5D Versus SF-12 in Coronary Patients: Are They Interchangeable?

ObjectivesThe aim of this study was to compare EuroQol five-dimensional (EQ-5D) utility scores and six-dimensional health state classification (SF-6D) utility scores (derived from the 12-Item Short-Form Health Survey [SF-12]) by using a large European sample of patients with stable coronary heart disease. Special attention was given to country-specific results. MethodsData from the EURopean Action on Secondary and Primary Prevention by Intervention to Reduce Events III (EUROASPIRE III) survey were used. Patients hospitalized for a coronary artery bypass graft, percutaneous coronary intervention, acute myocardial infarction, or myocardial ischemia were interviewed and examined at least 6 months after their acute event. Health-related quality of life was assessed by using the EQ-5D and the SF-12. SF-12 outcomes were converted to SF-6D utility values, allowing comparison between both measures. ResultsBoth EQ-5D and SF-6D results were available for 7472 patients with coronary heart disease from 20 European countries. The measures were significantly correlated (intraclass correlation coefficient = 0.536); however, large differences between the two measures remain. A total of 28.8% of the patients reported a ceiling effect on the EQ-5D instrument, whereas only 4.2% of the patients reported full health based on the SF-6D. Especially the mental component does not seem to be completely captured by the EQ-5D instrument. Furthermore, patients with worse EQ-5D outcomes were more likely to have better SF-6D results, whereas patients with better EQ-5D outcomes were more likely to have worse SF-6D results. ConclusionsBoth measures are not interchangeable. Whereas the main disadvantage of the EQ-5D questionnaire is its ceiling effect, the potential advantages of SF-12 might disappear when converting the outcomes into an SF-6D utility, because of the small differences between patients.

Properties of patient-reported outcome measures in individuals following acute whiplash injury.

BackgroundThe aim of this study was to assess the acceptability, reliability, validity and responsiveness of the Short-Form Health Survey (SF-12) and its preference-based derivative (SF-6D), the EQ-5D and the Neck Disability Index (NDI) in patients recovering from acute whiplash injury.MethodsData from the Managing Injuries of the Neck Trial of 3,851 patients with acute whiplash injury formed the basis of this empirical investigation. The EQ-5D and SF-12 were collected at baseline, and all three outcome measures were then collected at 4 months, 8 months and 12 months post-randomisation. The measures were assessed for their acceptability (response rates), internal consistency, validity (known groups validity and discriminant validity) and their internal and external responsiveness.ResultsResponse rates were broadly similar across the measures, with evidence of a floor effect for the NDI and a ceiling effect for the EQ-5D utility measure. All measures had Cronbach’s α statistics of greater than 0.7, indicating acceptable internal consistency. The NDI and EQ-5D utility score correlated more strongly with the physical component scale of the SF-12 than the mental component scale, whilst this was reversed for the SF-6D utility score. The smaller standard deviations in SF-6D utility scores meant there were larger effect sizes for differences in utility score between patients with different injury severity at baseline than for the EQ-5D utility measure. However, the EQ-5D utility measure and NDI were both more responsive to longitudinal changes in health status than the SF-6D.ConclusionsThere was no evidence of differences between the EQ-5D utility measure and NDI in terms of their construct validity, discriminant validity or responsiveness in patients with acute whiplash injury. However, both demonstrated superior responsiveness to longitudinal health changes than the SF-6D.

A systematic literature review of utility weights in wet age-related macular degeneration

Objective:The objective of the study was to conduct a systematic review of utility weight estimates relevant to economic models for wet age-related macular degeneration (wAMD).Methods:A systematic literature search of PubMed, Embase, the Cochrane Library, and EconLit was performed (January 1995–December 2010) and then updated (October 2010–May 2012; February 2012–July 2013) identifying articles reporting utilities in patients with wAMD and visual impairment. Extracted studies were also assessed for compliance with the NICE reference case.Results:Of 2415 articles identified from the searches, 212 articles were reviewed in full, and 17 selected for data extraction. Most studies used time trade-off (TTO) techniques to estimate utilities; other methods included standard gamble, EuroQoL Health Questionnaire 5 Dimensions (EQ-5D); Short-Form 6D Health Status Questionnaire (SF-6D); and Health Utilities Index Mark III (HUI3). Correlation between utility estimates and visual acuity (VA) differed between the instruments. Time trade-off methods were more sensitive to VA changes than standard gamble methods. HUI3 estimates were most highly correlated with VA changes, followed by TTO; no trend was observed between VA and EQ-5D or SF-6D utility weights. Six of the 17 studies complied with the NICE reference case.Conclusions:Several instruments have been used to elicit utilities from patients with wAMD. Because TTO methods were more sensitive to VA changes than standard gamble and HUI3 estimates were most highly correlated with VA changes, TTO and HUI3 may be suitable methods for economic evaluations in these patients. The EQ-5D and SF-6D were poor indicators of the impact of VA on HRQL.

Valuing SF-6D Health States Using a Discrete Choice Experiment

SF-6D utility weights are conventionally produced using a standard gamble (SG). SG-derived weights consistently demonstrate a floor effect not observed with other elicitation techniques. Recent advances in discrete choice methods have allowed estimation of utility weights. The objective was to produce Australian utility weights for the SF-6D and to explore the application of discrete choice experiment (DCE) methods in this context. We hypothesized that weights derived using this method would reflect the largely monotonic construction of the SF-6D. We designed an online DCE and administered it to an Australia-representative online panel (n = 1017). A range of specifications investigating nonlinear preferences with respect to additional life expectancy were estimated using a random-effects probit model. The preferred model was then used to estimate a preference index such that full health and death were valued at 1 and 0, respectively, to provide an algorithm for Australian cost-utility analyses. Physical functioning, pain, mental health, and vitality were the largest drivers of utility weights. Combining levels to remove illogical orderings did not lead to a poorer model fit. Relative to international SG-derived weights, the range of utility weights was larger with 5% of health states valued below zero. s. DCEs can be used to investigate preferences for health profiles and to estimate utility weights for multi-attribute utility instruments. Australian cost-utility analyses can now use domestic SF-6D weights. The comparability of DCE results to those using other elicitation methods for estimating utility weights for quality-adjusted life-year calculations should be further investigated.

Quality of life after off-pump vs on-pump coronary artery bypass grafting. A prospective randomized single center study

Results The two groups were comparable in terms of age, gender, body mass index, smoking habit. The results of the research showed a clear improvement in health-related quality of life of patients in both groups who underwent CABG, as compared to that prior to the intervention. But there were no statistically significant differences between the group that underwent conventional CABG and the group that underwent off-pump CABG, which is consistent with the existing literature. The index of SF-6D utility is highly correlated with CROQ when compared with the other utilities indexes and we propose its use in patients with coronary artery disease. Conclusion CABG modifies and improves the clinical presentation and patient’s quality of life, with no difference in health-related quality of life between off-pump and conventional CABG.