Are indirect utility measures reliable and responsive in rheumatoid arthritis patients?

Background: Preference-based, generic measures are increasingly being used to measure quality of life and as sources for quality weights in the estimation of Quality Adjusted Life Years (QALYs) in rheumatoid arthritis (RA). However, among the most commonly used instruments (the Health Utilities Index 2 and 3 [HUI2 and HUI3], the EuroQoL-5D [EQ-5D], and the Short Form-6D [SF-6D], there has been little comparative research. Therefore, we examined the reliability and responsiveness of these measures and the Rheumatoid Arthritis Quality of Life (RAQoL) and the Health Assessment Questionnaire (HAQ) in a sample of RA patients. Major findings: Test–retest reliability was acceptable for all of the instruments with the exception of the EQ-5D. Using two external criteria to define change (a patient transition question and categories of the patient global assessment of disease activity VAS), the RAQoL was the most responsive of the instruments. For the indirect utility instruments, the HUI3 and the SF-6D were the most responsive for measuring positive change. On average, for patients whose RA improved, the absolute change was highest for the HUI3. Conclusions: The HUI3 and the SF-6D appear to be the most responsive of the preference-based instruments in RA. However, differences in the magnitude of the absolute change scores have important implications for cost-effectiveness analyses.     

Comparing utility scores before and after hearing-aid provision

Utility scores were estimated for 609 hearing-impaired adults who completed EQ-5D, Health Utilities Index Mark III (HUI3) and SF-6D survey instruments both before and after being provided with a hearing aid. Pre-intervention, the mean utility scores for EQ-5D (0.80) and SF-6D (0.78) were significantly higher than the mean HUI3 utility score (0.58). Post-intervention, the mean improvement in the HUI3 (0.06 change) was significantly higher than the mean improvement according to the EQ-5D (0.01 change) or SF-6D (0.01 change). The estimated cost effectiveness of hearing-aid provision is therefore likely to be dependent on which instrument is used to measure utility.     

The validity of generic and condition-specific preference-based instruments: the ability to discriminate asthma control status

Objective A goal of asthma management is to improve the patient’s health-related quality of life (HRQL). However, it is unclear whether HRQL instruments can discriminate across asthma control measures. The objective of this study was to evaluate the validity of generic and condition-specific preference-based instruments, in terms of their ability to distinguish asthma control. Methods Asthma patients (n = 157) completed three generic preference-based instruments: the Health Utility Index Mark 3 (HUI-3), the EuroQol (EQ-5D), and the Short Form 6D (SF-6D) and two condition-specific questionnaires: the standardized Asthma Quality of Life Questionnaire (AQLQ(S)) and the Asthma Control Questionnaire (ACQ). The AQLQ(S) scores were converted into the condition-specific preference-based scores: the Asthma Quality of Life Utility Index (AQL-5D). Results The preference-based instruments were generally able to discriminate across control measures, such as ACQ scores and magnitude of asthma medication, but were not able to discriminate for self-reported control and severity levels. These instruments also correlated with most control measures (r = 0.32–0.37). Significant relationships between AQL-5D scores and all control variables were observed. Conclusions Overall, the AQL-5D discriminated across all levels of asthma control. The HUI-3, the EQ-5D, and the SF-6D differentiated between the highest and lowest levels of control but could not discriminate between the moderate levels.     

Assessing Differences in Utility Scores: A Comparison of Four Widely Used Preference-Based Instruments

OBJECTIVES: To characterize the differences in utility scores (dUTY) among four commonly used preference-based Health-Related Quality of Life instruments, to evaluate the potential impact of these differences on cost-utility analyses (CUA), and to determine if sociodemographic/clinical factors influenced the magnitude of these differences. METHODS: Consenting adult Chinese, Malay and Indian subjects in Singapore were interviewed using Singapore English, Chinese, Malay or Tamil versions of the EQ-5D, Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3), and SF-6D. Agreement between instruments was assessed using Bland-Altman (BA) plots. Changes in incremental cost-utility ratio (ICUR) from dUTY were investigated using eight hypothetical decision trees. The influence of sociodemographic/clinical factors on dUTY between instrument pairs was studied using multiple linear regression (MLR) models for English-speaking subjects (circumventing structural zero issues). RESULTS: In 667 subjects (median age 48 years, 59% female), median utility scores ranged from 0.80 (95% confidence interval [CI] 0.80, 0.85) for the EQ-5D to 0.89 (95% CI 0.88, 0.89) for the SF-6D. BA plots: Mean differences (95% CI) exceeded the clinically important difference (CID) of 0.04 for four of six pairwise comparisons, with the exception of the HUI2/EQ-5D (0.03, CI: 0.02, 0.04) and SF-6D/HUI2 (0.02, CI: 0.006, 0.02). Decision trees: The ICER ranged from $94,661/QALY (quality-adjusted life-year; 6.3% difference from base case) to 100,693 dollars/QALY (0.3% difference from base case). MLR: Chronic medical conditions, marital status, and Family Functioning Measures scores significantly (P-value < 0.05) influenced dUTY for several instrument pairs. CONCLUSION: Although CIDs in utility measurements were present for different preference-based instruments, the impact of these differences on CUA appeared relatively minor. Chronic medical conditions, marital status, and family functioning influenced the magnitude of these differences.     

Choosing between measures: comparison of EQ-5D,HUI2 and HUI3 in persons with hearing complaints

Objectives To generate insight into the differences between utility measures EuroQol 5D (EQ-5D), Health Utilities Index Mark II (HUI2) and Mark III (HUI3) and their impact on the incremental cost-effectiveness ratio (ICER) for hearing aid fitting Methods Persons with hearing complaints completed EQ-5D, HUI2 and HUI3 at baseline and, when applicable, after hearing aid fitting. Practicality, construct validity, agreement, responsiveness and impact on the ICER were examined. Results All measures had high completion rates. HUI3 was capable of discriminating between clinically distinctive groups. Utility scores (n = 315) for EQ-5D UK and Dutch tariff (0.83; 0.86), HUI2 (0.77) and HUI3 (0.61) were significantly different, agreement was low to moderate. Change after hearing aid fitting (n = 70) for HUI2 (0.07) and HUI3 (0.12) was statistically significant, unlike the EQ-5D UK (0.01) and Dutch (0.00) tariff. ICERs varied from €647,209/QALY for the EQ-5D Dutch tariff to €15,811/QALY for HUI3. Conclusion Utility scores, utility gain and ICERs heavily depend on the measure that is used to elicit them. This study indicates HUI3 as the instrument of first choice when measuring utility in a population with hearing complaints, but emphasizes the importance of a clear notion of what constitutes utility with regard to economic analyses.     

An assessment of validity and responsiveness of generic measures of health-related quality of life in hearing impairment

Purpose

This review examines psychometric performance of three widely used generic preference-based measures, that is, EuroQol 5 dimensions (EQ-5D), Health Utility Index 3 (HUI3) and Short-form 6 dimensions (SF-6D) in patients with hearing impairments.

Methods

A systematic search was undertaken to identify studies of patients with hearing impairments where health state utility values were measured and reported. Data were extracted and analysed to assess the reliability, validity (known group differences and convergent validity) and responsiveness of the measures across hearing impairments.

Results

Fourteen studies (18 papers) were included in the review. HUI3 was the most commonly used utility measures in hearing impairment. In all six studies, the HUI3 detected difference between groups defined by the severity of impairment, and four out of five studies detected statistically significant changes as a result of intervention. The only study available suggested that EQ-5D only had weak ability to discriminate difference between severity groups, and in four out of five studies, EQ-5D failed to detected changes. Only one study involved the SF-6D; thus, the information is too limited to conclude on its performance. Also evidence for the reliability of these measures was not found.

Conclusion

Overall, the validity and responsiveness of the HUI3 in hearing impairment was good. The responsiveness of EQ-5D was relatively poor and weak validity was suggested by limited evidence. The evidence on SF-6D was too limited to make any judgment. More head-to-head comparisons of these and other preference measures of health are required.     

A comparison of generic, indirect utility measures (the HUI2, HUI3, SF-6D, and the EQ-5D) and disease-specific instruments (the RAQoL and the HAQ) in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common, chronic disease where health-related quality of life (HRQL) is one of the main goals of therapy. As such, instruments used to measure HRQL in RA must be able to discriminate across RA severity. The two basic categories of instruments used to measure HRQL are generic instruments and disease-specific instruments. Generic instruments can be further subdivided into preference-based measures which yield both single and multi-attribute utility values anchored at zero (death) and 1.00 (perfect health) as a measure of HRQL. The scores from these types of instruments can be integrated into cost-utility analyses as the weightings for quality adjusted life years. We assessed the construct validity of utility scores from four generic preference-based measures (the Health Utilities Index 2 and 3 (HUI2, HUI3), the EuroQol 5D (EQ-5D), and the Short Form 6-D (SF-6D) and disease specific measures (the Rheumatoid Arthritis Quality of Life Questionnaire (RAQoL) and the Health Assessment Questionnaire (HAQ)) in a sample of 313 RA patients in British Columbia, Canada. We also estimated the minimally important differences (MID) for each of the measures. Generally, as anticipated, the disease-specific measures were better able to discriminate across groups with higher RA severity; however, utility scores from each of the scales also appeared to discriminate well across RA severity categories. The MID values agreed with those previously reported in the literature for the HUI2, SF-6D and the HAQ and provided new information for the HUI3, EQ-5D and the RAQoL. We conclude that the all of the preference-based utility measures that were evaluated appear to adequately discriminate across levels of RA severity.     

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.     

Comparing the Health Utilities Index Mark 3 (HUI3) with the Short Form-36 Preference-Based SF-6D in Chronic Kidney Disease

Objective:  Assess within-subject agreement and compare discriminative abilities between the SF-6D and the Health Utilities Index Mark 3 (HUI3) in patients with chronic kidney disease (CKD).
Methods:  The HUI3 and Short Form-36 were self-completed by 185 CKD patients enrolled in a prospective study of incident patients with stage 4 and 5 CKD.
Results:  The mean preference-based score for the SF-6D was 0.67 ± 0.13 compared to 0.58 ± 0.26 for the HUI3 ( P  < 0.01). There was a strong association between SF-6D and HUI3 scores (Pearson correlation coefficient 0.55, 95% CI 0.43–0.65) and moderate agreement with an intraclass correlation coefficient of 0.44. The HUI3 was better able to capture more severe burden of illness with fewer floor effects. The SF-6D was better at capturing differences among patients at the top range of the scale with fewer ceiling effects. Both the HUI3 and SF-6D were able to discriminate between patient groups differing in disease severity defined as predialysis versus dialysis dependent and depressive symptoms using a Beck Depression Inventory II score of ≥14 as the cutoff. The HUI3 was better able to discriminate greater depressive symptoms.
Conclusion:  The SF-6D and the HUI3 generate different preference-based scores for patients with CKD and any comparison between their scores should be made with caution. The HUI3 appears more suitable for measuring the health of populations with greater disability such as patients with CKD. It remains to be determined whether these differences will remain when one compares within-instrument differences in preference scores over time.     

Comparing Short Form 6D,Standard Gamble,and Health Utilities Index Mark 2 and Mark 3 utility scores: Results from total hip arthroplasty patients

Objective: The objectives are to compare SF-6D, standard gamble (SG), and Health Utilities Index (HUI) utility scores, compare change scores, and compare responsiveness. Methods: A cohort of osteoarthritis patients referred for total hip arthroplasty (THA) were evaluated at the time of referral and followed until 3months after THA. Patients were assessed using the SF-36, HUI2, HUI3, and the SG. Agreement is assessed using the intra-class correlation (ICC). Responsiveness is assessed using effect size, standardized response mean, and paired t-test. Results: Data was available for 86 patients at baseline and for 63 at both pre- and post-surgery. At baseline mean SF-6D (0.61), SG (0.62), and HUI2 (0.62) scores were similar; the mean HUI3 score (0.52) was lower. Standard deviations were 0.10, 0.32, 0.19, and 0.22. At baseline, agreement between SF-6D and SG scores was 0.13, agreement between SF-6D and HUI2 was 0.47, and agreement between SF-6D and HUI3 was 0.28. Agreement at pre- and post-surgery was similar. The change in scores between post- and pre-surgery was 0.10 for SF-6D, 0.16 for SG, 0.22 for HUI2, and 0.23 for HUI3. Effect sizes were 1.10 for HUI2, 1.08 for HUI3, 1.06 for SF-6D, and 0.48 for the SG. Conclusions: Agreement between SG scores and SF-6D and HUI scores was low. The estimate of change in utility associated with THA was lowest for SF-6D. Additional longitudinal studies to compare utility measures appear to be warranted.     

Is the Health Utilities Index responsive in total hip arthroplasty patients?

OBJECTIVE: The purpose is to examine the responsiveness of the Health Utilities Index Mark 2 (HUI2), Mark 3 (HUI3), and other generic and disease-specific measures in osteoarthritis patients undergoing total hip arthroplasty (THA). METHODS: Ninety patients (mean age=68.13; SD=8.15) on a waiting list for THA completed measures that included the standard gamble, HUI2, HUI3, SF-36, Harris Hip Scale, WOMAC, and MACTAR. before and after THA. Responsiveness statistics (effect size, standardized response mean, Guyatt's responsiveness statistic, paired-sample t-tests, and relative efficiency statistic) were calculated. RESULTS: The disease-specific measures were more responsive than the generic measures. Rankings of the degree of responsiveness varied depending on the responsiveness statistic used. CONCLUSIONS: Disease-specific measures are the most responsive in THA patients. However, the SF-36, HUI2, and HUI3 had summary scores and domain/attributes scores that were also responsive and provided additional information. Among the generic measures, HUI3 was the most responsive.     

The effect of weight loss on changes in health-related quality of life among overweight and obese women with urinary incontinence

Objective

To estimate the effect of change in weight and change in urinary incontinence (UI) frequency on changes in preference-based measures of health-related quality of life (HRQL) among overweight and obese women with UI participating in a weight loss trial.

Methods

We conducted a longitudinal cohort analysis of 338 overweight and obese women with UI enrolled in a randomized clinical trial comparing a behavioral weight loss intervention to an educational control condition. At baseline, 6, and 18?months, health utilities were estimated using the Health Utilities Index Mark 3 (HUI3), a transformation of the SF-36 to the preference-based SF-6D, and the estimated Quality of Well-Being (eQWB) score (a summary calculated from the SF-36 physical functioning, mental health, bodily pain, general health perceptions, and role limitations?Cphysical subscale scores). Potential predictors of changes in these outcomes were examined using generalized estimating equations.

Results

In adjusted multivariable models, weight loss was associated with improvement in HUI3, SF-6D, and eQWB at 6 and 18?months (P?<?0.05). Increases in physical activity also were independently associated with improvement in HUI3 (P?=?0.01) and SF-6D (P?=?0.006) scores at 18?months. In contrast, reduction in UI frequency did not predict improvements in HRQL at 6 or 18?months.

Conclusion

Weight loss and increased physical activity, but not reduction in UI frequency, were strongly associated with improvements in health utilities measured by the HUI3, SF-6D, and eQWB. These findings provide important information that can be used to inform cost?Cutility analyses of weight loss interventions.     

Effects of Mode and Order of Administration on Generic Health-Related Quality of Life Scores

ObjectiveWe evaluate the effects of mode and order of administration on health-related quality of life (HRQOL) scores.MethodWe analyzed HRQOL data from the Clinical Outcomes and Measurement of Health Study (COMHS). In COMHS, we enrolled patients with heart failure or cataracts at three sites (University of California, San Diego, University of California, Los Angeles, and University of Wisconsin). Patients completed self-administered HRQOL instruments at baseline and months 1 and 6 post-baseline, including the EuroQol (EQ-5D), Health Utilities Index (HUI), Quality of Well-Being Scale—self-administered (QWB-SA), and the Short Form (SF)-36v2. At the 6 months follow-up, individuals were randomized to mail or telephone administration first, followed by the other mode of administration. We used repeated measures mixed effects models, adjusting for site, patient age, education, gender, and race.ResultsIncluded were 121 individuals entering a heart failure program and 326 individuals scheduled for cataract surgery who completed the survey by mail or phone at the 6-month follow-up. The majority of the sample was female (53%) and white (86%). About a quarter of the sample had high school education or less (26%). The average age was 66 (36–91 range). HRQOL scores were higher (more positive) for phone administration following mail administration. The largest differences in scores between phone and mail responses occurred for comparisons of telephone responses for those who were randomized to a mail survey first compared with mail responses for those randomized to a telephone survey first (i.e., mode effects for responses that were given on the second administration of the HRQOL measures). The QWB-SA was the only measure that did not display the pattern of mode effects. The biggest differences between modes were 4 points on the SF-36v2 physical health and mental health component summary scores, 0.06 on the SF-6D, 0.03 on the QWB-SA, 0.08 on the EQ-5D, 0.04 on the HUI2, and 0.10 on the HUI3.ConclusionsTelephone administration yields significantly more positive HRQOL scores for all of the generic HRQOL measures except for the QWB-SA. The magnitude of effects was clearly important, with some differences as large as a half-standard deviation. These findings confirm the importance of considering mode of administration when interpreting HRQOL scores.     

Comparison of the Health Utilities Index Mark 3 (HUI3) and the EuroQol EQ-5D in patients treated for intermittent claudication

The Health Utilities Index Mark 3 (HUI3) and the EuroQol EQ-5D (EQ-5D) were compared to each other and to other quality-of-life (QoL) measures in patients treated for intermittent claudication. A total of 88 patients with intermittent claudication completed the HUI3, EQ-5D, RAND 36-Item Health Survey 1.0, time tradeoff, standard gamble, and rating scale before revascularization and at follow-up at 1 month, 3 months, and 1 year. The effect of treatment on the HUI3 and EQ-5D dimensions and the overall scores, calculated using published formulas based on societal preferences, were compared. After 1 month of treatment, the majority of patients showed improvement on the HUI3 dimensions ambulation and pain and on the EQ-5D dimensions mobility, usual activities, and pain/discomfort. The mean HUI3 score was significantly higher than the mean EQ-5D score (0.66 and 0.57, respectively, p < 0.01) before treatment. After treatment, however, they were not significantly different from each other (e.g., 12 months after treatment: 0.77 and 0.75, respectively (p > 0.05). After 1 month, the scores did not change significantly over time (p > 0.05). The intraclass correlation coefficient between changes over time in the HUI3 and EQ-5D scores was 0.30, with other health-related quality-of-life (HRQoL) measures the correlations for HUI3 and EQ-5D were very similar. In conclusion, both the HUI3 and EQ-5D demonstrated an effect of treatment in patients with intermittent claudication; in addition, they showed similar relationships with other (HRQoL) measures. To demonstrate the effect of revascularization in patients with intermittent claudication, however, clinicians and researchers should be aware of the differences in the mean HUI3 and EQ-5D scores. This revised version was published online in June 2006 with corrections to the Cover Date.     

A Review of the Psychometric Performance of Selected Child and Adolescent Preference-Based Measures Used to Produce Utilities for Child and Adolescent Health

ObjectiveThis review examined the psychometric performance of 4 generic child- and adolescent-specific preference-based measures that can be used to produce utilities for child and adolescent health.MethodsA systematic search was undertaken to identify studies reporting the psychometric performance of the Child Health Utility (CHU9D), EQ-5D-Y (3L or 5L), and Health Utilities Index Mark 2 (HUI2) or Mark 3 (HUI3) in children and/or adolescents. Data were extracted to assess known-group validity, convergent validity, responsiveness, reliability, acceptability, and feasibility. Data were extracted separately for the dimensions and utility index where this was reported.ResultsThe review included 76 studies (CHU9D n = 12, EQ-5D-Y-3L n = 20, HUI2 n = 26,HUI3 n = 43), which varied considerably across conditions and sample size. EQ-5D-Y-3L had the largest amount of evidence of good psychometric performance in proportion to the number of studies examining performance. The majority of the evidence related to EQ-5D-Y-3L was based on dimensions. CHU9D was assessed in fewer studies, but the majority of studies found evidence of good psychometric performance. Evidence for HUI2 and HUI3 was more mixed, but the studies were more limited in sample size and statistical power, which was likely to have affected performance.ConclusionsThe heterogeneity of published studies means that the evidence is based on studies across a range of countries, populations and conditions, using different study designs, different languages, different value sets and different statistical techniques. Evidence for CHU9D in particular is based on a limited number of studies. The findings raise concerns about the comparability of self-report and proxy-report responses to generate utility values for children and adolescents.     

What is the evidence for the performance of generic preference-based measures? A systematic overview of reviews

Objective

To assess the evidence on the validity and responsiveness of five commonly used preference-based instruments, the EQ-5D, SF-6D, HUI3, 15D and AQoL, by undertaking a review of reviews.

Methods

Four databases were investigated using a strategy refined through a highly sensitive filter for systematic reviews. References were screened and a search for grey literature was performed. Identified citations were scrutinized against pre-defined eligibility criteria and data were extracted using a customized extraction template. Evidence on known group validity, convergent validity and responsiveness was extracted and reviewed by narrative synthesis. Quality of the included reviews was assessed using a modified version of the AMSTAR checklist.

Results

Thirty reviews were included, sixteen of which were of excellent or good quality. The body of evidence, covering more than 180 studies, was heavily skewed towards EQ-5D, with significantly fewer studies investigating HUI3 and SF-6D, and very few the 15D and AQoL. There was also lack of head-to-head comparisons between GPBMs and the tests reported by the reviews were often weak. Where there was evidence, EQ-5D, SF-6D, HUI3, 15D and AQoL seemed generally valid and responsive instruments, although not for all conditions. Evidence was not consistently reported across reviews.

Conclusions

Although generally valid, EQ-5D, SF-6D and HUI3 suffer from some problems and perform inconsistently in some populations. The lack of head-to-head comparisons and the poor reporting impedes the comparative assessment of the performance of GPBMs. This highlights the need for large comparative studies designed to test instruments’ performance.

     

Health-related quality of life and utilities in primary-care patients with generalized anxiety disorder

Background  Generalized anxiety disorder (GAD) is prevalent and significantly impacts patient health-related quality of life (HRQL) and disability. Purpose  This study evaluated the effect of GAD and anxiety symptom severity on the HRQL of primary-care patients with GAD. Methods  Patients 18 years or older with GAD were recruited from an integrated health care delivery system. Clinical assessments included the Hamilton Anxiety Rating Scale (HAM-A), GAD Questionnaire-IV (GAD-Q-IV), and the Patient Health Questionnaire depression module (PHQ). HRQL was assessed by the Quality of Life Enjoyment and Satisfaction Questionnaire—Short Form (Q-LES-Q-SF), Sheehan Disability Scale (SDS), SF-12 Health Survey (SF-6D), and the Health Utilities Index (HUI2, HUI3). Results  The sample included 297 patients, 72% women with mean ± standard deviation (SD) age of 47.6 ± 13.7 years. At baseline, the mean HAM-A score was 16.8 ± 7.6 (suggesting the presence of moderate anxiety symptoms). Anxiety and depression symptoms were significantly correlated with mental component summary (MCS), Q-LES-Q-SF, SDS, SF-6D, HUI2, and HUI3 scores (all P < 0.001). The mean HRQL and all of the preference-based measures varied significantly by anxiety severity groups (all P < 0.001). Anxiety and depression symptoms significantly predicted HRQL and preference-based scores (R ² values ranged from 0.22 to 0.57). Conclusions  Anxiety symptoms reported by GAD patients resulted in significant impairment to HRQL and functional outcomes.