Psychometric evaluation of the German version of the Recovering Quality of Life (ReQoL) measures in patients with affective disorders

BACKGROUND

The generic self-reported Recovering Quality of Life (ReQoL) measures were developed for measuring recovery-focused health-related quality of life (HrQoL) in persons with mental health conditions. The aim of this study was to assess the psychometric properties of the German version of the ReQoL measures in patients with affective disorders in Germany.

METHODS

Data from a patient sub-sample in a randomized controlled trial have been used (N = 393). The internal consistency and the test-retest reliability of the ReQoL measures were assessed using Cronbach's Alpha and the intra-class correlation coefficient (ICC). The concurrent validity and the known-group validity of the ReQoL measures were assessed using Pearson's Correlation coefficient and Cohen's d. The responsiveness was assessed using Glass' Δ and the standardized response mean (SRM).

RESULTS

The reliability among the items of the ReQoL-20 was overall excellent. The ICC of the ReQoL-20 was r = 0.70, indicating moderate test-retest reliability. The concurrent validity of the ReQoL-20 with the clinical measure PHQ-9 was strong with a correlation coefficient of r = - 0.76. The known-group validity of the ReQoL-20 using PHQ-9 cut-off points was large with an effect size of d = 1.63. The ReQoL measures were sensitive to treatment response and remission of symptoms measured by the PHQ-9 with large effect sizes/SRM.

DISCUSSION

The psychometric properties of the ReQoL measures for the assessment of patients with affective disorders were overall good. With the ReQoL, valid and reliable measures for the assessment of recovery-focused HrQoL for persons with affective disorders are available in German language.

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.

The validity of the SF-12 and SF-6D instruments in people living with HIV/AIDS in Kenya

Background

Health-related quality of life (HRQoL) and health state utility value (HSUV) measurements are vital components of healthcare clinical and economic evaluations. Accurate measurement of HSUV and HRQoL require validated instruments. The 12-item Short-Form Health Survey (SF-12) is one of few instruments that can evaluate both HRQoL and HSUV, but its validity has not been assessed in people living with HIV/AIDS (PLWHA) in east Africa, where the burden of HIV is high.

Methods

This cross-sectional study used baseline data from a randomized trial involving PLWHA in Kenya. Data included responses from a translated and adapted SF-12 survey as well as key demographic and clinical data. Construct validity of the survey was examined by testing the SF-12’s ability to distinguish between groups known in advance to have differences in their health based on their disease severity. We classified disease severity based on established definitions from the US Center for Disease Control (CDC) and WHO, as well as a previously studied viral load threshold. T-tests and ANOVA were used to test for differences in HRQoL and HSUV scores. Area under the receive operator curve (AUC) was used to test the discriminative ability of the HRQoL and HSUV instruments.

Results

Differences in physical component scores met the minimum clinically important difference among participants with more advanced HIV when defined by CD4 count (4.3 units) and WHO criteria (compared to stage 1, stages 2, 3 and 4 were 2.0, 7.2 and 9.8 units lower respectively). Mental score differences met the minimum clinically important difference between WHO stage 1 and stage 4 patients (4.4). Differences in the HSUV were statistically lower in more advanced HIV by all three definitions of severity. The AUC showed poor to weak discriminatory ability in most analyses, but had fair discriminatory ability between WHO clinical stage 1 and clinical stage 4 individuals (AUC = 0.71).

Conclusion

Our findings suggest that the Kiswahili translated and adapted version of the SF-12 could be used as an assessment tool for physical health, mental health and HSUV for Kiswahili-speaking PLHWA.

Trial registration

Clinical trials.gov identifier: NCT00830622. Registered 26 January 2009.

Catalog and comparison of societal preferences (utilities) for lung cancer health states: results from the Cancer Care Outcomes Research and Surveillance (CanCORS) study

BACKGROUND

The EQ-5D and SF-6D are 2 health-related quality-of-life indexes that provide preference-weighted measures for use in cost-effectiveness analyses.

METHODS

The National Cancer Institute's Cancer Care Outcomes Research and Surveillance (CanCORS) Consortium included the EQ-5D and SF-12v2 in their survey of newly diagnosed lung cancer patients. Utilities were calculated from patient-provided scores for each domain of the EQ-5D or the SF-6D. Utilities were calculated for categories of cancer type, stage, and treatment.

RESULTS

There were 5015 enrolled lung cancer patients with a baseline survey in CanCORS; 2396 (47.8%) completed the EQ-5D, and 2344 (46.7%) also completed the SF-12v2. The mean (standard deviation) utility from the EQ-5D was 0.78 (0.18), and from the SF-6D (derived from SF-12v2) was 0.68 (0.14). The EQ-5D demonstrated a ceiling effect, with 20% of patients reporting perfect scores, translating to a utility of 1.0. No substantial SF-6D floor effects were noted. Utilities increased with age and decreased with stage and comorbidities. Patient-reported (EQ-5D) visual analog scale scores for health status had a moderate (r = 0.48, p < 0.0001) positive correlation with utilities. A subset (n = 1474) completed follow-up EQ-5D questionnaires 11-13 months after diagnosis. Among these patients, there was a nonsignificant decrease in mean utility for stage IV and an increase in mean utility for stages I, II, and III.

CONCLUSION

This study generated a catalog of community-weighted utilities applicable to societal-perspective cost-effectiveness analyses of lung cancer interventions and compared utilities based on the EQ-5D and SF-6D. Potential users of these scores should be aware of the limitations and think carefully about their use in specific studies.