Comparison of EQ-5D and SF-6D utilities in mental health patients

Various preference-based measures of health are available for use as an outcome measure in cost-utility analysis. The aim of this study is to compare two such measures EQ-5D and SF-6D in mental health patients. Baseline data from a Dutch multi-centre randomised trial of 616 patients with mood and/or anxiety disorders were used. Mean and median EQ-5D and SF-6D utilities were compared, both in the total sample and between severity subgroups based on quartiles of SCL-90 scores. Utilities were expected to decline with increased severity.Both EQ-5D and SF-6D utilities differed significantly between patients of adjacent severity groups. Mean utilities increased from 0.51 at baseline to 0.68 at 1.5 years follow-up for EQ-5D and from 0.58 to 0.70 for SF-6D. For all severity subgroups, the mean change in EQ-5D utilities as well as in SF-6D utilities was statistically significant. Standardised response means were higher for SF-6D utilities. We concluded that both EQ-5D and SF-6D discriminated between severity subgroups and captured improvements in health over time. However, the use of EQ-5D resulted in larger health gains and consequent lower cost-utility ratios, especially for the subgroup with the highest severity of mental health problems.     

Development and testing of the UK SF-12 (short form health survey)

OBJECTIVES: The 36 item short form health survey (SF-36) has proved to be of use in a variety of settings where a short generic health measure of patient-assessed outcome is required. This measure can provide an eight dimension profile of health status, and two summary scores assessing physical function and mental well-being. The developers of the SF-36 in America have developed algorithms to yield the two summary component scores in a questionnaire containing only one-third of the original 36 items, the SF-12. This paper documents the construction of the UK SF-12 summary measures from a large-scale dataset from the UK in which the SF-36, together with other questions on health and lifestyles, was sent to randomly selected members of the population. Using these data we attempt here to replicate the findings of the SF-36 developers in the UK setting, and then to assess the use of SF-12 summary scores in a variety of clinical conditions. METHODS: Factor analytical methods were used to derive the weights used to construct the physical and mental component scales from the SF-36. Regression methods were used to weight the 12 items recommended by the developers to construct the SF-12 physical and mental component scores. This analysis was undertaken on a large community sample (n = 9332), and then the results of the SF-36 and SF-12 were compared across diverse patient groups (Parkinson's disease, congestive heart failure, sleep apnoea, benign prostatic hypertrophy). RESULTS: Factor analysis of the SF-36 produced a two factor solution. The factor loadings were used to weight the physical component summary score (PCS-36) and mental component summary score (MCS-36). Results gained from the use of these measures were compared with results gained from the PCS-12 and MCS-12, and were found to be highly correlated (PCS: rho = 0.94, p < 0.001; MCS: rho = 0.96, p < 0.001), and produce remarkably similar results, both in the community sample and across a variety of patient groups. CONCLUSIONS: The SF-12 is able to produce the two summary scales originally developed from the SF-36 with considerable accuracy and yet with far less respondent burden. Consequently, the SF-12 may be an instrument of choice where a short generic measure providing summary information on physical and mental health status is required.     

Mental and physical health status among chronic hepatitis B patients

Quality of Life Research - Little is known about health-related quality of life (HRQoL) in patients with chronic hepatitis B virus (CHB) infection in the United States. Our goal is to understand...     

Use of Bayesian methods to model the SF-6D health state preference based data

Background

Conventionally, models used for health state valuation data have been frequentists. Recently a number of researchers have investigated the use of Bayesian methods in this area. The aim of this paper is to put on the map of modelling a new approach to estimating SF-6D health state utility values using Bayesian methods. This will help health care professionals in deriving better health state utilities of the original UK SF-6D for their specialized applications.

Methods

The valuation study is composed of 249 SF-6D health states valued by a representative sample of the UK population using the standard gamble technique. Throughout this paper, we present four different models, including one simple linear regression model and three random effect models. The predictive ability of these models is assessed by comparing predicted and observed mean SF-6D scores, R²/adjusted R² and RMSE. All analyses were carried out using Bayesian Markov chain Monte Carlo (MCMC) simulation methods freely available in the specialist software WinBUGS.

Results

The random effects model with interaction model performs best under all criterions, with mean predicted error of 0.166, R²/adjusted R² of 0.683 and RMSE of 0.218.

Conclusions

The Bayesian models provide flexible approaches to estimate mean SF-6D utility estimates, including characterizing the full range of uncertainty inherent in these estimates. We hope that this work will provide applied researchers with a practical set of tools to appropriately model outcomes in cost-effectiveness analysis.

     

Comparison of EQ-5D,HUI, and SF-36-derived societal health state values among Spine Patient Outcomes Research Trial (SPORT) participants

Purpose: To compare societal values across health-state classification systems and to describe the performance of these systems at baseline in a large population of persons with confirmed diagnosis of intervertebral disc herniation (IDH), spinal stenosis (SpS), or degenerative spondylolisthesis (DS). Methods: We compared values for EQ-5D (York weights), HUI (Mark 2 and 3), SF-6D, and the SF-36-derived estimate of the Quality of Well Being (eQWB) score using signed rank tests. We tested each instruments ability to discriminate between health categories and level of symptom satisfaction. Correlations were assessed with Spearman rank correlations. We evaluated ceiling and floor effects by comparing the proportion at the highest and the lowest possible score for each tool. In addition, we compared proportions at the highest and lowest levels by dimension. The number of unique health states assigned was compared across instruments. We calculated the difference between those who were very dissatisfied and all others. Results: Mean values ranged from 0.39 to 0.63 among 2097 participants ages 18–93 (mean age 53, 47 female) with significant differences in pair-wise comparisons noted for all systems. Correlations ranged from 0.30 to 0.78. Although all systems showed statistically significant differences in health state values when baseline comparisons were made between those who were very dissatisfied with their symptoms and those who were not, the magnitude of this difference ranged widely across systems. Mean differences (95 CI) between those very dissatisfied and all others were 0.30 (0.269, 0.329) for EQ-5D, 0.22 (0.190, 0.241) for HUI(3), 0.18 (0.161, 0.201) for HUI(2), 0.11 (0.095, 0.117) for SF-6D, 0.04 (0.039, 0.049) for eQWB, and 0.07 (0.056, 0.077) for VAS (with transformation applied to group means). Conclusion: Differences in preference-weighted health state classification systems are evident at baseline in a population with confirmed IDH, SpS, and DS. Caution should be used when comparing health state values derived from various systems.     

Mapping chronic liver disease questionnaire scores onto SF-6D utility values in patients with primary sclerosing cholangitis

Purpose

The chronic liver disease questionnaire (CLDQ) is a frequently used liver-specific quality of life instrument, but it does not provide information on preference-adjusted health status, which is essential for cost-utility analysis. We aimed to develop a mapping function deriving utilities from the CLDQ in primary sclerosing cholangitis (PSC).

Methods

Short form-6D (SF-6D) utilities were calculated from SF-36 data collected in a recent prospective study in which unselected patients with PSC also completed the CLDQ. Ordinary least squares (OLS), generalized linear, median, and kernel regression analyses were employed to devise a mapping function predicting utilities. This was validated in three random subsamples of the cohort and in a separate sample of PSC patients following liver transplantation. Adjusted R ² and root-mean-square error (RMSE) as well as Pearson’s r coefficients and mean absolute errors between predicted and observed values were used to determine model performance.

Results

Decompensated liver disease and fatigue, systemic symptoms, and emotional distress, assessed with the CLDQ, were related to worse SF-6D utilities. The final OLS prediction model explained 66.3 % of the variance in the derivation sample. Predicted and observed utilities were strongly correlated (r = 0.807, p < 0.001), but the mean absolute error (0.0604) and adjusted RMSE (10.6 %) were of intermediate size. Similar model characteristics were observed after employment of generalized linear and median regression models and at validation.

Conclusions

A model has been constructed, showing good validity predicting SF-6D utilities from CLDQ scores at the group level in PSC. Further testing is required to externally validate the model.

     

Exploring the validity of estimating EQ-5D and SF-6D utility values from the health assessment questionnaire in patients with inflammatory arthritis

Background  

Utility scores are used to estimate Quality Adjusted Life Years (QALYs), applied in determining the cost-effectiveness of health care interventions. In studies where no preference based measures are collected, indirect methods have been developed to estimate utilities from clinical instruments. The aim of this study was to evaluate a published method of estimating the EuroQol-5D (EQ-5D) and Short Form-6D (SF-6D) (preference based) utility scores from the Health Assessment Questionnaire (HAQ) in patients with inflammatory arthritis.     

Comparison of Euroqol EQ-5D and SF-36 in patients with chronic fatigue syndrome

The objective of the study was to compare the Euroqol EQ-5D (Euroqol) and short-form 36 (SF-36) health questionnaires in patients with chronic fatigue syndrome (CFS). One hundred and twenty-seven out-patients referred to a hospital-based infectious disease clinic with a diagnosis of CFS were contacted by post and asked to complete both questionnaires. Additional data were determined from hospital casenotes. Eighty-five patients returned correctly completed questionnaires. Euroqol health values and visual analogue scale (VAS) scores were strongly and significantly correlated with all dimensions of the SF-36, with the exception of physical limitation of role. SF-36 dimensions were in turn strongly and significantly correlated with each other, with the same exception. Patients reported a high degree of physical disability and a moderate degree of emotional or psychological ill-health. The Euroqol elements dealing with mobility and self-care referred to inappropriately severe degrees of disability for these patients with CFS. Similarly some dimensions in the SF-36 were oversensitive and did not discriminate between patients with moderate or severe disability. It was concluded that Euroqol scores correlated strongly with SF-36 scores and provided useful information about patients with CFS and that Euroqol would be a useful tool for the rapid assessment of health status in CFS. The current Euroqol instrument refers to inappropriately severe degrees of disability for patients with CFS and would need to be modified to be maximally useful in this situation.     

体检人群中乙型肝炎患者健康干预效果评价

目的探讨健康查体人群中乙型肝炎(简称乙肝)患者健康干预社会服务的效果。方法选择市区机关企事业单位体检人群中查出的乙肝患者87例,随机分为观察组(43例)和对照组(44例),收集两组病例一般资料,对观察组病例资料进行详细的评价,分析汇总,制定个性化的健康干预方案,并开展一系列良好的社会支持服务。而对照组采用常规的健康宣传教育方式。然后定期观察,随访一年,不同健康干预方式干预后,两组病例的医嘱执行情况、生活质量及疾病转归等情况。结果观察组病例的医嘱执行情况、生活质量及疾病转归等明显优于对照组,(P<0.05),有统计学差异。结论个性化健康干预,是促使乙肝患者早日康复,提高生活质量回归社会的一种有效方法。     

Estimation and comparison of derived preference scores from the SF-36 in lung transplant patients

The purpose of this study was to estimate and compare preference scores derived from MOS Short Form-36 (SF-36) data for a sample of lung transplant patients using three methodologies: Fryback et al. (Med Decis Making 1997; 17: 1-9), Nichol et al. (Med Decis Making 2001; 21: 105-112) and Brazier et al. (J Health Econ 2002: 21: 271-292). Data were gathered from 99 lung transplant recipients using a mail survey, which included the SF-36 and other health-related quality of life (HRQL) measures. The mean preference score for the sample was 0.643 (range 0.43-0.83), 0.765 (range 0.36-1.0), and 0.697 (range 0.33-1.00) for Fryback, Nichol and Brazier methods, respectively. Correlations between the derived scores and visual analogue ratings of health (0.58-0.68) and pulmonary symptoms (-0.59 to -0.62) were moderate to good and in the expected directions. The mean preferences of patients grouped by levels of dyspnea, depression symptoms, illness burden, and self-rated general health differed significantly with all methods and supported the construct validity of the derived scores as measures of preference. The Nichol and Brazier scores, both derived with standard gamble utilities, were generally higher than Fryback scores, which are not utility-based. Given the popularity of the SF-36, these three methods could be useful where direct elicitation of preferences is not feasible. Researchers must be cognizant of the derivation method used, as absolute preference levels, hence quality adjusted life years (QALYs), will differ by method.     

EQ-5D and SF-6D health utility scores in patients with spinal and bulbar muscular atrophy

The European Journal of Health Economics - This study assessed patient-reported health-related quality of life (HRQoL) using two generic preference-based measures in Chinese patients with spinal...     

Comparison of the minimally important difference for two health state utility measures: EQ-5D and SF-6D

Background: The SF-6D and EQ-5D are both preference-based measures of health. Empirical work is required to determine what the smallest change is in utility scores that can be regarded as important and whether this change in utility value is constant across measures and conditions. Objectives: To use distribution and anchor-based methods to determine and compare the minimally important difference (MID) for the SF-6D and EQ-5D for various datasets. Methods: The SF-6D is scored on a 0.29–1.00 scale and the EQ-5D on a −0.59–1.00 scale, with a score of 1.00 on both, indicating ‘full health’. Patients were followed for a period of time, then asked, using question 2 of the SF-36 as our anchor, if their general health is much better (5), somewhat better (4), stayed the same (3), somewhat worse (2) or much worse (1) compared to the last time they were assessed. We considered patients whose global rating score was 4 or 2 as having experienced some change equivalent to the MID. This paper describes and compares the MID and standardised response mean (SRM) for the SF-6D and EQ-5D from eight longitudinal studies in 11 patient groups that used both instruments. Results: From the 11 reviewed studies, the MID for the SF-6D ranged from 0.011 to 0.097, mean 0.041. The corresponding SRMs ranged from 0.12 to 0.87, mean 0.39 and were mainly in the ‘small to moderate’ range using Cohen’s criteria, supporting the MID results. The mean MID for the EQ-5D was 0.074 (range −0.011–0.140) and the SRMs ranged from −0.05 to 0.43, mean 0.24. The mean MID for the EQ-5D was almost double that of the mean MID for the SF-6D. Conclusions: There is evidence that the MID for these two utility measures are not equal and differ in absolute values. The EQ-5D scale has approximately twice the range of the SF-6D scale. Therefore, the estimates of the MID for each scale appear to be proportionally equivalent in the context of the range of utility scores for each scale. Further empirical work is required to see whether or not this holds true for other utility measures, patient groups and populations.     

Discriminative capacity of the EQ-5D, SF-6D, and SF-12 as measures of health status in population health survey

Purpose

To compare the EQ-5D, SF-6D, and SF-12 in terms of their capacity to discriminate between groups defined by relevant socio-demographic and health characteristics in a general population survey.

Methods

Data were obtained from the 2006 Catalan Health Interview Survey, a representative sample (n = 4,319) of the general population of Catalonia (Spain). Effect sizes (ES) and Receiver Operating Characteristic (ROC) curves were calculated to evaluate the instruments’ capacity to distinguish between groups based on socio-demographic variables, recent health problems, perceived health, psychological distress, and selected chronic conditions.

Results

All instruments showed a similar discriminative capacity between groups based on socio-demographic variables, recent medical visit (ES = 0.47–0.55), activity limitations (ES = 0.92–0.98), perceived health (ES = 0.97–1.33), and psychological well-being (ES = 1.17–1.57). Effect sizes between respondents with and without any of fourteen selected chronic conditions were large (0.76–1.04) for 4, moderate (0.55–0.74) for 8, and small (0.17–0.39) for two on the EQ-5D index. A similar pattern was observed for the SF-12 but ES were predominantly moderate (7 conditions) or small (6 conditions) on the SF-6D.

Conclusions

The EQ-5D and SF-12 were largely comparable in estimating the health burden of chronic conditions, recent health problems, and social inequalities. The SF-6D was less sensitive than the EQ-5D index and SF-12, particularly for physical chronic conditions.     

Development and initial validation of the chronic hepatitis B quality of life instrument (CHBQOL) among Chinese patients

Quality of Life Research - This study developed and tested preliminary measurement properties of a Chinese scale specifically designed to measure HRQOL in patients with chronic hepatitis B...     

健康教育对门诊慢性病毒性肝炎患者的干预研究

我国慢性病毒性肝炎患者发病率呈上升趋势,居世界首位,严重威胁着人民的身心健康。由于该病具有传染性强且病情反复迁延等特性,故患者需要反复就医,坚持遵医嘱服药,并配合做好生活起居等各方面的调理,才能使病情保持稳定,防止病情发展和恶化。     

Search for hepatitis delta virus (HDV) infection in hepatitis C patients in north-eastern Poland. Comparison with anti-HDV prevalence in chronic hepatitis B

Hepatitis C virus and hepatitis D virus have been shown to suppress HBsAg synthesis. Thus it is possible that HDV infection occurs despite the lack of detectable HBsAg. The aim of our study was to (a) determine the prevalence of HDV infection in patients with chronic hepatitis C (b) compare it with the prevalence of HDV infection in HBsAg positive patients with hepatitis B. The study group consisted of 51 chronic hepatitis C patients, 30 HIV infected drug addicts (27 of them were also positive for anti-HCV) and 102 hepatitis B patients. The participants were tested for anti-HDV, anti-HCV and HBsAg. All anti-HCV positive patients were negative for anti-HDV. Four individuals with anti-HDV belonged to hepatitis B group and constituted 3.9% of all HBsAg positive subjects. We conclude that (a) there is currently no evidence of HDV infection among HCV infected patients in our region (b) hepatitis delta infection is rare in north-eastern Poland.     

Estimating health utilities in patients with asthma and COPD: evidence on the performance of EQ-5D and SF-6D

Objective  The objective of this study was to understand systematic differences in utility values derived from the EQ-5D and the SF-6D in two respiratory populations with heterogeneous disease severity. Methods  This study involved secondary analysis of data from two cross-sectional surveys of patients with asthma (N = 228; Hungary) and COPD (N = 176; Sweden). Disease severity was defined according to GINA and GOLD guidelines for asthma and COPD, respectively. EQ-5D and SF-6D scores and their distributional characteristics were compared across the two samples by disease severity level. Results  Within each patient population, mean EQ-5D and SF-6D scores were similar for the overall group and for those with moderate disease. Mean scores varied for patients with mild and severe disease. EQ-5D versus SF-6D scores in the asthma group by severity levels were 0.89 versus 0.80, 0.70 versus 0.73, 0.63 versus 0.64, and 0.51 versus 0.63, respectively. EQ-5D versus SF-6D scores in the COPD group by severity levels were 0.85 versus 0.80, 0.73 versus 0.73, 0.74 versus 0.73, and 0.53 versus 0.62, respectively. Conclusions  Results suggest the EQ-5D and SF-6D do not yield consistent utility values in patients with asthma and COPD due to differences in underlying valuation techniques and the EQ-5D’s limited response options relative to mild disease.