A comparative study of Chinese medicine quality of life assessment scale (CQ-11D) and EQ-5D-5L and SF-6D scales based on Chinese population.

PURPOSE: To measure health-related quality of life in the Chinese population using three universal health utility scales (CQ-11D, EQ-5D-5L, and SF-6D) and to compare the differences in the results obtained by the different scales to provide a reference for future utility on health-related quality of life in the Chinese population. METHODS: According to the Chinese population's distribution area, gender, and age, quota sampling was conducted. Three scales, CQ-11D, EQ-5D-5L, and SF-6D, whose results were self-reported, were collected in succession after collecting respondents' demographic information. The health utility value and floor/ceiling effect were explained. Bland-Altman was used to evaluate the consistency, the intraclass correlation coefficient was used to evaluate the correlation, and the receiver operating characteristic curve was used to evaluate the discriminative validity of the scale. RESULTS: The mean utility values of the CQ-11D, EQ-5D-5L, and SF-6D scales, respectively, were 0.891, 0.927, and 0.841. The floor effect did not appear in any of the three scales, but the ceiling effect did, and the EQ-5D-5L ceiling effect was the most severe. The limits of the agreement interval for CQ-11D versus EQ-5D-5L in the total sample population were (-0.245,0.172); for CQ-11D versus SF-6D, they were (- 0.256,0.354); and for EQ-5D-5L versus SF-6D, they were (-0.199,0.371). The consistency of the three scales is satisfactory overall. In the total population, the intraclass correlation coefficient between CQ-11D and EQ-5D-5L was 0.709, while EQ-5D-5L and SF-6D were 0.0.565 and that between EQ-5D-5L and SF-6D was 0.472. According to the subject operation curve results, the area under the curve for the total sample population of CQ-11D was 0.746, EQ-5D-5L was 0.669, and SF-6D was 0.734. CONCLUSION: The CQ-11D is inferior to the EQ-5D-5L, but superior to the SF-6D. There is a strong correlation between the health utility values of the total population as measured by the three scales and those of the healthy population. The CQ-11D scale is the most sensitive to differences between populations and diseases.

Estimating the disutility of relapse in relapsing-remitting and secondary progressive multiple sclerosis using the EQ-5D-5L, AQoL-8D, EQ-5D-5L-psychosocial, and SF-6D: implications for health economic evaluation models.

BACKGROUND AND AIMS: Relapses are an important clinical feature of multiple sclerosis (MS) that result in temporary negative changes in quality of life (QoL), measured by health state utilities (HSUs) (disutilities). We aimed to quantify disutilities of relapse in relapsing remitting MS (RRMS), secondary progressive MS (SPMS), and relapse onset MS [ROMS (including both RRMS and SPMS)] and examine these values by disability severity using four multi-attribute utility instruments (MAUIs). METHODS: We estimated (crude and adjusted and stratified by disability severity) disutilities (representing the mean difference in HSUs of 'relapse' and 'no relapse' groups as well as 'unsure' and 'no relapse' groups) in RRMS (n = 1056), SPMS (n = 239), and ROMS (n = 1295) cohorts from the Australian MS Longitudinal Study's 2020 QoL survey, using the EQ-5D-5L, AQoL-8D, EQ-5D-5L-Psychosocial, and SF-6D MAUIs. RESULTS: Adjusted mean overall disutilities of relapse in RMSS/SPMS/ROMS were - 0.101/- 0.149/- 0.129 (EQ-5D-5L), - 0.092/- 0.167/- 0.113 (AQoL-8D), - 0.080/- 0.139/- 0.097 (EQ-5D-5L-Psychosocial), and - 0.116/- 0.161/- 0.130 (SF-6D), approximately 1.5 times higher in SPMS than in RRMS, in all MAUI. All estimates were statistically significant and/or clinically meaningful. Adjusted disutilities of RRMS and ROMS demonstrated a U-shaped relationship between relapse disutilities and disability severity. Relapse disutilities were higher in 'severe' disability than 'mild' and 'moderate' in the SPMS cohort. CONCLUSION: MS-related relapses are associated with substantial utility decrements. As the type and severity of MS influence disutility of relapse, the use of disability severity and MS-type-specific disutility inputs is recommended in future health economic evaluations of MS. Our study supports relapse management and prevention as major mechanisms to improve QoL in people with MS.

Mapping the schizophrenia quality of life scale to EQ-5D, HUI3 and SF-6D utility scores in patients with schizophrenia.

OBJECTIVES: The current study aimed to map the disease-specific Schizophrenia Quality of Life Scale (SQLS) onto the three- and five-level EuroQol five-dimension (EQ-5D-3 L and EQ-5D-5 L), Health Utility Index Mark 3 (HUI3) and Short Form six-dimensional (SF-6D) preference-based instruments to inform future cost-utility analyses for treatment of patients with schizophrenia. METHODS: Data from 251 outpatients with schizophrenia spectrum disorders was included for analysis. Ordinary least square (OLS), Tobit and beta regression mixture models were employed to estimate the utility scores. Three regression models with a total of 66 specifications were determined by goodness of fit and predictive indices. Distribution of the original data to the distributions of the data generated using the preferred estimated models were then compared. RESULTS: EQ-5D-3 L and EQ-5D-5 L were best predicted by the OLS model, including SQLS domain scores, domain-squared scores, age, and gender as explanatory predictors. The models produced the best performance index and resembled most closely with the observed EQ-5D data. HUI3 and SF-6D were best predicted by the OLS and Tobit model respectively. CONCLUSION: The current study developed mapping models for converting SQLS scores into generic utility scores, which can be used for economic evaluation among patients with schizophrenia.

Health utility in community-dwelling adults with dysvascular lower limb loss.

PURPOSE: Adults with dysvascular lower extremity amputation (LEA) experience a large number of secondary health conditions yet there is a gap in the literature on health utility scores for this population. A health utility score relates to a person's state of well-being, and is a single metric anchored at 0 (death) and 1 (perfect health). This study aimed to provide a descriptive account of health utility scores in community-dwelling adults with dysvascular LEA. METHODS: Participants were adults with dysvascular LEA who were 3 months post-amputation. Data collected included socio-demographic characteristics, the Special Interest Group in Amputee Medicine (SIGAM) grades, the dysvascular conditions scale (DCS), which is a scale developed for this study, and the Short Form-36 (SF-36). SF-6D health utility scores were derived from the SF-36 using a software algorithm. Participants were grouped into low-impact and high-impact groups based on self-reported severity of symptoms using the DCS. Health utility scores were compared between the low-impact and high-impact groups using independent t-tests. RESULTS: A total of 231 participants were enrolled in the study. The mean SF-6D health utility score was 0.689 (0.127). A significant association was found between health utility score and SIGAM grade (p < 0.001, η2 = .09). Health utility was positively associated with age (r = 0.137, p = 0.037) and months post-amputation (r = 0.141, p = 0.032), and negatively associated with DCS severity (r = -0.526, p < 0.001). Health utility scores were lower for participants in the DCS high-impact groups for conditions such as diabetes mellitus, phantom limb pain, musculoskeletal pain, back pain, psychological distress, depression, vision problems, and other pain. CONCLUSION: Cost-utility analyses rely on health utility estimates and our findings provide data for future economic evaluations that may assist policy makers in evidence informed allocation of healthcare resources for this population.

Assessment of health-related quality of life in individuals with depressive symptoms: validity and responsiveness of the EQ-5D-3L and the SF-6D.

BACKGROUND: The EQ-5D and the SF-6D are examples of commonly used generic preference-based instruments for assessing health-related quality of life (HRQoL). However, their suitability for mental disorders has been repeatedly questioned. OBJECTIVE: To assess the responsiveness and convergent validity of the EQ-5D-3L and SF-6D in patients with depressive symptoms. METHODS: The data analyzed were from cardiac patients with depressive symptoms and were collected as part of the SPIRR-CAD (Stepwise Psychotherapy Intervention for Reducing Risk in Coronary Artery Disease) trial. The EQ-5D-3L and SF-6D were compared with the HADS (Hospital Anxiety and Depression Scale) and PHQ-9 (Patient Health Questionnaire) as disease-specific instruments. Convergent validity was assessed using Spearman's rank correlation. Effect sizes were calculated and ROC analysis was performed to determine responsiveness. RESULTS: Data from 566 patients were analysed. The SF-6D correlated considerably better with the disease-specific instruments (|rs|= 0.63-0.68) than the EQ-5D-3L (|rs|= 0.51-0.56). The internal responsiveness of the SF-6D was in the upper range of a small effect (ES: - 0.44 and - 0.47), while no effect could be determined for the EQ-5D-3L. Neither the SF-6D nor the EQ-5D-3L showed acceptable external responsiveness for classifying patients' depressive symptoms as improved or not improved. The ability to detect patients whose condition has deteriorated was only acceptable for the EQ-5D-3L. CONCLUSION: Overall, both the convergent validity and responsiveness of the SF-6D are better than those of the EQ-5D-3L in patients with depressive symptoms. The SF-6D appears, therefore, more recommendable for use in studies to evaluate interventions for this population.

Mapping analysis to predict SF-6D utilities from health outcomes in people with focal epilepsy.

BACKGROUND: Focal-onset seizures (FOS) are commonly experienced by people with epilepsy and have a significant impact on quality of life (QoL). This study aimed to develop a mapping algorithm to predict SF-6D values in adults with FOS for use in economic evaluations of a new treatment, cenobamate. METHODS: An online survey, including questions on disease history, SF-36, and an epilepsy-specific measure (QOLIE-31-P) was administered to people with FOS in the UK, France, Italy, Germany, and Spain. A range of regression models were fitted to SF-6D scores including direct and response mapping approaches. RESULTS: 361 individuals were included in the analysis. In the previous 28 days, the mean number of FOS experienced was 3, (range 0-43) and the mean longest period of consecutive days without experiencing a seizure was 14 days (range 1-28 days or more). Mean responses on all SF-36 dimensions were lower than general population norms. Mean SF-6D and QOLIE-31-P scores were 0.584 and 45.72, respectively. The best performing model was the ordinary least squares (OLS), with root mean squared error and mean absolute error values of 0.0977 and 0.0742, respectively. Explanatory variables which best predicted SF-6D included seizure frequency, severity, freedom, and age. CONCLUSION: People with uncontrolled FOS have poor QoL. The mapping algorithm enables the prediction of SF-6D values from clinical outcomes in people with FOS. It can be applied to outcome data from clinical trials to facilitate cost-utility analysis.

Association Between Cognition, Health Related Quality of Life, and Costs in a Population at Risk for Cognitive Decline.

BACKGROUND: The association between health-related quality of life (HRQoL) and care costs in people at risk for cognitive decline is not well understood. Studying this association could reveal the potential benefits of increasing HRQoL and reducing care costs by improving cognition. OBJECTIVE: In this exploratory data analysis we investigated the association between cognition, HRQoL utilities and costs in a well-functioning population at risk for cognitive decline. METHODS: An exploratory data analysis was conducted using longitudinal 2-year data from the FINGER study (n = 1,120). A change score analysis was applied using HRQoL utilities and total medical care costs as outcome. HRQoL utilities were derived from the Short Form Health Survey-36 (SF-36). Total care costs comprised visits to a general practitioner, medical specialist, nurse, and days at hospital. Analyses were adjusted for activities of daily living (ADL) and depressive symptoms. RESULTS: Although univariable analysis showed an association between cognition and HRQoL utilities, multivariable analysis showed no association between cognition, HRQoL utilities and total care costs. A one-unit increase in ADL limitations was associated with a -0.006 (p < 0.001) decrease in HRQoL utilities and a one-unit increase in depressive symptoms was associated with a -0.004 (p < 0.001) decrease in HRQoL utilities. CONCLUSION: The level of cognition in people at-risk for cognitive decline does not seem to be associated with HRQoL utilities. Future research should examine the level at which cognitive decline starts to affect HRQoL and care costs. Ideally, this would be done by means of cross-validation in populations with various stages of cognitive functioning and decline.

A head-to-head comparison of EQ-5D-5L and SF-6D in Dutch patients with fractures visiting a Fracture Liaison Service.

AIMS: This study compared the psychometric properties of EQ-5D-5L and SF-6D to assess the interchangeability of both instruments in patients with a recent fracture presenting at a Fracture Liaison Service (FLS). MATERIALS AND METHODS: Data from a prospective observational study in a Dutch FLS clinic were used. Over 3 years, subjects were interviewed at several time points using EQ-5D-5L and SF-36. Floor and ceiling effects were evaluated. Agreement was evaluated by intra-class correlation coefficients and visualized in Bland-Altman plots. Spearman's rank correlation coefficients were applied to assess convergent validity. Mann-Whitney U test or Kruskal-Wallis H test as well as effect size (ES) were used to explore known-groups validity. Responsiveness was explored using standardized response mean (SRM) and ES. For each measurement property, hypotheses on direction and magnitude of effects were formulated. RESULTS: A total of 499 patients were included. EQ-5D-5L had a considerable ceiling effect in comparison to SF-6D (21 vs. 1.2%). Moderate agreement between the (UK and Dutch) EQ-5D-5L and SF-6D was identified with intra-class correlation coefficients of 0.625 and 0.654, respectively. Bland-Altman plots revealed proportional bias as the differences in utilities between two instruments were highly dependent on the health states. High correlation between instruments was found (UK: rho = 0.758; Dutch: rho = 0.763). EQ-5D-5L and SF-6D utilities showed high correlation with physical component score but low correlation with mental component score of SF-36. Both instruments showed moderate discrimination (ES > 0.5) for subgroup by baseline fracture type, and moderate responsiveness (SRM > 0.5) in patients that sustained a subsequent fracture. CONCLUSION: Both EQ-5D-5L and SF-6D appeared to be valid utility instruments in patients with fractures attending the FLS. However, they cannot be used interchangeably given only moderate agreement was identified, and differences in utilities and ceiling effect were revealed. Comparable construct validity and responsiveness were indicated, and neither instrument was found to be clearly superior.

The EQ-5D and SF-36 as generic multi-domain questionnaires are widely used to measure the health-related quality-of-life (HRQoL) in a sample of the persons who suffer from the diseases or the general population. Their responses could be converted to patients or societal Health State Utility Values (HSUVs) with the range of 0 ("death") to 1 ("full health"). A specific application of HSUV is to calculate quality-adjusted life years as the indicator of effectiveness to evaluate whether the cost of a new intervention is justified in terms of health gains through cost-utility analysis in health economics, the evidence can be further used to inform decision-making. However, different instruments differ in construct and valuation, potentially leading to different estimates for the person's same "health state", and healthcare decisions could be compromised when researchers or decision-makers are not aware of potential differences in HSUV. Therefore, it is important to gain insight into the specific psychometric properties of these instruments, and to understand whether instruments are interchangeable. Our study is based on data from a Dutch Fracture Liaison Service (FLS is a program for secondary fracture prevention), compared the psychometric properties and interchangeability of two instruments (EQ-5D-5L and SF-6D) in patients with a recent fracture presenting at the FLS, and suggested both instruments are valid in utility elicitation in our target population. However, they cannot be used interchangeably given only moderate agreement and differences in utilities. Neither instrument was found to be clearly superior given comparable construct and longitudinal validity, but different instruments values in different aspects of HRQoL assessment.

Health-Related Quality of Life Evaluation Using the Short Form-36 in Patients With Human T-Lymphotropic Virus Type 1-Associated Myelopathy.

Background: Human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM) is a neuroinflammatory disease, causing various neurological symptoms, including motor, sensory, and bladder and bowel dysfunctions. This study was designed to reveal the impact of HAM and related symptoms on health-related quality of life (HRQoL). Methods: We analyzed the Short Form-36 (SF-36) and clinical data of 538 patients with HAM registered in the HAM-net, a nationwide patient registry for HAM in Japan. HRQoL was evaluated using the SF-6D (a health state utility value calculated from the SF-36) and eight SF-36 subscales. A general liner model was used to estimate the impact of major HAM-related symptoms, including gait dysfunction, sensory disturbance in the legs (pain and numbness), urinary dysfunction, and constipation, on the SF-6D and SF-36 subscale scores. Results: The mean age and disease duration were 62.0 and 16.5 years, respectively. Of the patients, 73.2% needed walking aid; 42.7 and 67.1% had leg pain and numbness, respectively; 92.1% had urinary dysfunction; and 77.9% had constipation. The mean SF-6D score was 0.565, which was significantly lower than the national average (0.674 in the 60-69 years age group; p < 0.001), exceeding the minimal important difference (0.05-0.1). All the major symptoms were significantly associated with a decrease in the SF-6D score. The SF-36 subscale scores were significantly lower than the national standard of 50 (p ≤ 0.001), except for mental health (MH). Gait dysfunction was associated with lower scores in physical functioning (PF), limitations on role functioning because of physical health, bodily pain, general health perception (GH), vitality (VT), and social functioning; however, no association was observed between gait dysfunction and limitations on role functioning because of emotional problems and MH. Meanwhile, sensory disturbance in the legs was associated with a decrease in scores in all subscales. Urinary dysfunction was associated with worse PF, GH, VT, and MH. Constipation was associated only with PF. Conclusion: HRQoL of patients with HAM was worse than that of the general population and was associated with all major symptoms. Thus, patients should be comprehensively managed to achieve better HRQoL.

Modeling SF-6D Health Utilities: Is Bayesian Approach Appropriate?

BACKGROUND: Valuation studies of preference-based health measures like SF6D have been conducted in many countries. However, the cost of conducting such studies in countries with small populations or low- and middle-income countries (LMICs) can be prohibitive. There is potential to use results from readily available countries' valuations to produce better valuation estimates. METHODS: Data from Lebanon and UK SF-6D value sets were analyzed, where values for 49 and 249 health states were extracted from samples of Lebanon and UK populations, respectively, using standard gamble techniques. A nonparametric Bayesian model was used to estimate a Lebanon value set using the UK data as informative priors. The resulting estimates were then compared to a Lebanon value set obtained using Lebanon data by itself via various prediction criterions. RESULTS: The findings permit the UK evidence to contribute potential prior information to the Lebanon analysis by producing more precise valuation estimates than analyzing Lebanon data only under all criterions used. CONCLUSIONS: The positive findings suggest that existing valuation studies can be merged with a small valuation set in another country to produce value sets, thereby making own country value sets more attainable for LMICs.

Health-Related Quality of Life and Health Utilities of Mild, Moderate, and Severe Asthma: Evidence from the Medical Expenditure Panel Survey.

BACKGROUND: Little information is known about the health-related quality of life (HRQOL) and the patient's preference values by the severity of asthma. We evaluated the HRQOL and health utility impairment associated with asthma severity using the SF-12 and SF-6D. METHODS: We conducted a cross-sectional analysis of 2010-2016 Medical Expenditure Panel Survey database of asthma patients aged ≥18 years and categorized them into mild, moderate, and severe asthma. Study outcomes included the SF-12 physical component summary (PCS) and mental component summary (MCS) for measuring HRQOL and SF-6D for health utility. Survey regression models were used to estimate HRQOL and utilities for mild, moderate, and severe asthma. RESULTS: Of 10,222 patients with asthma, 75.4%, 23.9%, and 0.8% had mild, moderate and severe asthma. We observed that the greater the severity, the lower the SF-6D scores: 0.731 in mild, 0.723 in moderate, and 0.659 in severe asthma (P < 0.001). Patients with severe asthma had a significantly lower PCS compared to those with mild asthma (-5.3; P < 0.001) but there was no significant difference in MCS (-1.9; P = 0.309) controlling for socioeconomic and clinical variables. Asthma severity, women, older age, and having a lower level education and public insurance were significantly associated with lower PCS (P < 0.01). CONCLUSION: Asthma patients had worse physical HRQOL than mental health, especially patients with severe asthma. These data suggest that the management of physical health of female, older aged, and low education patients with asthma should be focused on improving HRQOL.

Stress-related health depreciation: Using allostatic load to predict self-rated health.

Approximately one quarter of UK adults are currently diagnosed with two or more chronic conditions, often referred to as multimorbidity. Chronic stress has been implicated in the development of many diseases common to multimorbidity. Policymakers and clinicians have acknowledged the need for more preventative approaches to deal with the rise of multimorbidity and "early ageing". However divergence may occur between an individual's self-rated health and objectively measured health that may preclude preventative action. The use of biomarkers which look 'under the skin' provide crucial information on an individual's underlying health to facilitate lifestyle change or healthcare utilisation. The UK's Understanding Society dataset, was used to examine whether baseline variation in biomarkers measuring stress-related "wear and tear" - Allostatic Load (AL) - predict changes in future self-rated health (SRH) while adjusting for baseline SRH, socioeconomic and lifestyle factors, and healthcare inputs. An interaction between baseline AL and baseline SRH was included to test for differential rates of SRH change. We examined SRH using the SF6D instrument, measuring health-related-quality of life (HRQoL), as well as its physical and mental health components separately. We found that HRQoL and physical health decline faster for those with higher baseline AL (indicating greater "wear and tear") however the same pattern was not observed for mental health. These findings provide novel insights for clinicians and policymakers on the usefulness of AL in capturing health trajectories of which individual's may not be aware and its importance in targeting resilience enhancing measures earlier in the lifecourse to delay physical health decline.

Mapping the Memorial Anxiety Scale for Prostate Cancer to the SF-6D.

PURPOSE: To create a crosswalk that predicts Short Form 6D (SF-6D) utilities from Memorial Anxiety Scale for Prostate Cancer (MAX-PC) scores. METHODS: The data come from prostate cancer patients enrolled in the North Carolina Prostate Cancer Comparative Effectiveness & Survivorship Study (NC ProCESS, N = 1016). Cross-sectional data from 12- to 24-month follow-up were used as estimation and validation datasets, respectively. Participants' SF-12 scores were used to generate SF-6D utilities in both datasets. Beta regression mixture models were used to evaluate SF-6D utilities as a function of MAX-PC scores, race, education, marital status, income, employment status, having health insurance, year of cancer diagnosis and clinically significant prostate cancer-related anxiety (PCRA) status in the estimation dataset. Models' predictive accuracies (using mean absolute error [MAE], root mean squared error [RMSE], Akaike information criterion [AIC] and Bayesian information criterion [BIC]) were examined in both datasets. The model with the highest prediction accuracy and the lowest prediction errors was selected as the crosswalk. RESULTS: The crosswalk had modest prediction accuracy (MAE = 0.092, RMSE = 0.114, AIC = - 2708 and BIC = - 2595.6), which are comparable to prediction accuracies of other SF-6D crosswalks in the literature. About 24% and 52% of predictions fell within ± 5% and ± 10% of observed SF-6D, respectively. The observed mean disutility associated with acquiring clinically significant PCRA is 0.168 (standard deviation = 0.179). CONCLUSION: This study provides a crosswalk that converts MAX-PC scores to SF-6D utilities for economic evaluation of clinically significant PCRA treatment options for prostate cancer survivors.

Association between knee symptoms, change in knee symptoms over 6-9 years, and SF-6D health state utility among middle-aged Australians.

OBJECTIVES: Health state utilities (HSUs) are an input metric for estimating quality-adjusted life-years (QALY) in cost-utility analyses. Currently, there is a paucity of data on association of knee symptoms with HSUs for middle-aged populations. We aimed to describe the association of knee symptoms and change in knee symptoms with SF-6D HSUs and described the distribution of HSUs against knee symptoms' severity. METHODS: Participants (36-49-years) were selected from the third follow-up (completed 2019) of Australian Childhood Determinants of Adult Health study. SF-6D HSUs were generated from the participant-reported SF-12. Association between participant-reported WOMAC knee symptoms' severity, change in knee symptoms over 6-9 years, and HSUs were evaluated using linear regression models. RESULTS: For the cross-sectional analysis, 1,567 participants were included; mean age 43.5 years, female 54%, BMI ± SD 27.18 ± 5.31 kg/m2. Mean ± SD HSUs for normal, moderate, and severe WOMAC scores were 0.820 ± 0.120, 0.800 ± 0.120, and 0.740 ± 0.130, respectively. A significant association was observed between worsening knee symptoms and HSUs in univariable and multivariable analyses after adjustment (age and sex). HSU decrement for normal-to-severe total-WOMAC and WOMAC-pain was - 0.080 (95% CI - 0.100 to - 0.060, p < 0.01) and - 0.067 (- 0.085 to - 0.048, p < 0.01), exceeding the mean minimal clinically important difference (0.04). Increase in knee pain over 6-9 years was associated with a significant reduction in HSU. CONCLUSION: In a middle-aged population-based sample, there was an independent negative association between worse knee symptoms and SF-6D HSUs. Our findings may be used by decision-makers to define more realistic and conservative baseline and ongoing HSU values when assessing QALY changes associated with osteoarthritis interventions.

Validity and responsiveness of EQ-5D-5L and SF-6D in patients with health complaints attributed to their amalgam fillings: a prospective cohort study of patients undergoing amalgam removal.

BACKGROUND: Evidence of health utility changes in patients who suffer from longstanding health complaints attributed to dental amalgam fillings are limited. The change in health utility outcomes enables calculating quality-adjusted life-year (QALY) and facilitates the comparison with other health conditions. The purpose of this study was to estimate the validity and responsiveness of the EQ-5D-5L and SF-6D utilities following removal of dental amalgam fillings in patients with health complaints attributed to their amalgam fillings, and examine the ability of these instruments to detect minimally important changes over time. METHODS: Patients with medically unexplained physical symptoms, which they attributed to dental amalgam restorations, were recruited to a prospective cohort study in Norway. Two health state utility instruments, EQ-5D-5L and SF-6D, as well as self-reported general health complaints (GHC-index) and visual analogue scale (EQ-VAS) were administered to all patients (n = 32) at baseline and at follow-up. The last two were used as criteria measures. Concurrent and predictive validities were examined using correlation coefficients. Responsiveness was assessed by the effect size (ES), standardized response mean (SRM), and relative efficiency. Minimally important change (MIC) was examined by distribution and anchor-based approaches. RESULTS: Concurrent validity of the EQ-5D-5L was similar to that of SF-6D utility. EQ-5D-5L was more responsive than SF-6D: the ES were 0.73 and 0.58 for EQ-5D-5L and SF-6D, respectively; SRM were 0.76 and 0.67, respectively. EQ-5D-5L was more efficient than SF-6D in detecting changes, but both were less efficient compared to criteria-based measures. The estimated MIC of EQ-5D-5L value set was 0.108 and 0.118 based on distribution and anchor-based approaches, respectively. The corresponding values for SF-6D were 0.048 and 0.064, respectively. CONCLUSIONS: In patients with health complaints attributed to dental amalgam undergoing amalgam removal, both EQ-5D-5L and SF-6D showed reasonable concurrent and predictive validity and acceptable responsiveness. The EQ-5D-5L utility appears to be more responsive compared to SF-6D. Trial registration The research was registered at ClinicalTrials.gov., NCT01682278. Registered 10 September 2012, https://clinicaltrials.gov/ct2/show/NCT01682278 .

Bayesian modeling of health state preferences: could borrowing strength from existing countries' valuations produce better estimates.

BACKGROUND: Valuations of preference-based measure such as EQ-5D and/or SF6D have been conducted in different countries. There is potential to borrow strength from existing countries' valuations to generate better representative utility estimates. This is explored using two case studies modelling UK data alongside Japan samples to generate Japan estimates. METHODS: Data from two SF-6D valuation studies were analyzed, where using similar standard gamble protocols, values for 241 and 249 states were devised from representative samples of Japan and UK general adult populations, respectively. Two nonparametric Bayesian models were applied to estimate a Japan value set, where the UK results were used as informative priors in the first model and subsets of the Japan data set for 25 and 50 health states were modelled alongside the full UK data set in the second. Generated estimates were compared to a Japan value set estimated using Japan values alone using different prediction criterion. RESULTS: The results allowed the UK data to provide significant prior information to the Japan analysis by generating better estimates than using Japan data alone. Also, using Japan data elicited for 50 health states alongside the existing UK data produces roughly similar predicted valuations as the Japan data by itself. CONCLUSION: The promising results suggest that the existing preference data could be combined with data from a valuation study in a new country to generate preference weights, thus making own country value sets more achievable for low-middle income countries. Further research and application to other countries and preference-based measures are encouraged.

Measuring health-related quality of life in patients treated for substance dependence: differences among instruments and methods of eliciting preferences.

BACKGROUND: Measuring the health-related quality of life is an essential estimation in cost-utility studies. In this research, we provide new evidence about comparing utility scores - in the field of substance dependence. Although the main objective is to compare the EQ-5D-5L and SF-6D with paired gamble, evidence about the SF-6D with standard gamble is also provided. METHODS: Ninety-four patients with substance dependence were recruited; the SF-6D and the EQ-5D-5L were administered at the beginning of treatment and 6 months thereafter. Differences in treatment effect were estimated by comparing utility gains. All analyses were reproduced for two subgroups of severity. RESULTS: Both the baseline scores and the treatment effect are sensitive to the instrument used. For severe states, the SF-6D with paired gamble (SF-6D with standard gamble) estimates the lowest (highest) utility. With regard to the impact of treatment, the EQ-5D-5L and SF-6D with paired gamble estimate strongly similar effects for severe states (and both estimate greater effects than does the SF-6D with standard gamble). CONCLUSIONS: These findings have implications for cost-utility analyses. The incremental cost-utility ratio of treatments intended for severe states is barely sensitive to the choice of EQ-5D-5L or SF-6D with paired gamble.

Health related quality of life utility weights for economic evaluation through different stages of chronic kidney disease: a systematic literature review.

BACKGROUND: A Task Force from the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) provides recommendations on how to systematically identify and appraise health state utility (HSU) weights for cost-effectiveness analyses. We applied these recommendations to conduct a systematic review (SR) to identify HSU weights for different stages of chronic kidney disease (CKD), renal replacement therapy (RRT) and complications. METHODS: MEDLINE® and Embase were searched for interventional and non-interventional studies reporting HSU weights for patients with CKD stages 1-5 or RRT. As per ISPOR Task Force Guidance, study quality criteria, applicability for Health Technology Assessment (HTA) and generalisability to a broad CKD population were used to grade studies as either 1 (recommended), 2 (to be considered if there are no data from grade 1 studies) or 3 (not recommended). RESULTS: A total of 17 grade 1 studies were included in this SR with 51 to 1767 participants, conducted in the UK, USA, Canada, China, Spain, and multiple-countries. Health related quality of life (HRQL) instruments used in the studies included were EQ-5D-3L (10 studies), SF-6D (4 studies), HUI2/HUI3 (1 study), and combinations (2 studies). Although absolute values for HSU weights varied among instruments, HSU weights decreased with CKD severity in a consistent manner across all instruments. CONCLUSIONS: This SR identified HSU weights for a range of CKD states and showed that HRQL decreases with CKD progression. Data were available to inform cost-effectiveness analysis in CKD in a number of geographies using instruments acceptable by HTA agencies.

The Importance of Accounting for Parameter Uncertainty in SF-6D Value Sets and Its Impact on Studies that Use the SF-6D to Measure Health Utility.

BACKGROUND: The parameter uncertainty in the six-dimensional health state short form (SF-6D) value sets is commonly ignored. There are two sources of parameter uncertainty: uncertainty around the estimated regression coefficients and uncertainty around the model's specification. This study explores these two sources of parameter uncertainty in the value sets using probabilistic sensitivity analysis (PSA) and a Bayesian approach. METHODS: We used data from the original UK/SF-6D valuation study to evaluate the extent of parameter uncertainty in the value set. First, we re-estimated the Brazier model to replicate the published estimated coefficients. Second, we estimated standard errors around the predicted utility of each SF-6D state to assess the impact of parameter uncertainty on these estimated utilities. Third, we used Monte Carlo simulation technique to account for the uncertainty on these estimates. Finally, we used a Bayesian approach to quantifying parameter uncertainty in the value sets. The extent of parameter uncertainty in SF-6D value sets was assessed using data from the Hong Kong valuation study. RESULTS: Including parameter uncertainty results in wider confidence/credible intervals and improved coverage probability using both approaches. Using PSA, the mean 95% confidence intervals widths for the mean utilities were 0.1394 (range: 0.0565-0.2239) and 0.0989 (0.0048-0.1252) with and without parameter uncertainty whilst, using the Bayesian approach, this was 0.1478 (0.053-0.1665). Upon evaluating the impact of parameter uncertainty on estimates of a population's mean utility, the true standard error was underestimated by 79.1% (PSA) and 86.15% (Bayesian) when parameter uncertainty was ignored. CONCLUSIONS: Parameter uncertainty around the SF-6D value set has a large impact on the predicted utilities and estimated confidence intervals. This uncertainty should be accounted for when using SF-6D utilities in economic evaluations. Ignoring this additional information could impact misleadingly on policy decisions.

Measuring intangible cost-of-morbidity due to substance dependence: implications of using alternative preference-based instruments.

OBJECTIVE: Drug and/or alcohol dependence (DAD) generates substantial costs to society. One of the main consequences of DAD is its negative impact on health-related quality of life (HRQoL). The main objective of this study is to analyse the impact of using EQ-5D-5L, SF-6DSG (SF-6D using standard-gamble as the preference-eliciting method) and SF-6DPG (SF-6D using a paired-gamble method), to estimate the HRQoL burden, attributable to DAD, within the cost-of-illness framework. METHODS: A convenience sample of 109 patients with a diagnosis of substance use disorder was recruited. SF-6D and EQ-5D-5L were administered and then the utility scores were computed. The impact of employing different instruments to estimate the HRQoL burden was assessed by comparing the utility scores of patients and general population after controlling for sex and age through regression analysis. The analysis was reproduced for two subgroups of severity. RESULTS: All instruments detect that DAD significantly affects the HRQoL. However, the estimated impact changes, according to the instrument used, whose pattern varies by severity group. Nonetheless, regardless of severity, SF-6DPG always estimates a higher or equal DAD burden than the other instruments considered. These results are compatible with the presence of the floor effect in SF-6DSG, the ceiling effect in EQ-ED-5L, and a smaller presence of both biases in SF-6DPG. CONCLUSIONS: The SF-6DPG instrument emerges as a good candidate to avoid under-estimating intangible costs within the cost-of-illness framework. However, further research is needed to assess the validity of our results in the context of other health problems.