Published in:
01-08-2016 | Original Research Article
A Head-to-Head Comparison of the EQ-5D-5L and AQoL-8D Multi-Attribute Utility Instruments in Patients Who Have Previously Undergone Bariatric Surgery
Published in: The Patient - Patient-Centered Outcomes Research | Issue 4/2016
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Background
Psychosocial health status is an important and dynamic outcome for bariatric/metabolic surgery patients, as acknowledged in recent international standardised outcomes reporting guidelines. Multi-attribute utility-instruments (MAUIs) capture and assess an individual’s health-related quality-of-life (HRQoL) within a single valuation, their utility. Neither MAUIs nor utilities were discussed in the guidelines. Many MAUIs (e.g. EQ-5D) target physical health. Not so the AQoL-8D.
Objectives
Our objective was to explore agreement between, and suitability of, the EQ-5D-5L and AQoL-8D for assessing health state utility, and to determine whether either MAUI could be preferentially recommended for metabolic/bariatric surgery patients.
Methods
Utilities for post-surgical private-sector patients (n = 33) were assessed using both instruments and summary statistics expressed as mean [standard deviation (SD)] and median [interquartile range (IQR)]. Interchangeability of the MAUIs was assessed with Bland–Altman analysis. Discriminatory attributes were investigated through floor/ceiling effects and dimension-to-dimension comparisons. Spearman’s rank measured associations between the instruments’ utility values and with the body mass index (BMI).
Results
Mean (SD) EQ-5D-5L utility value was 0.84 (0.15) and median 0.84 (IQR 0.75–1.00). Mean (SD) AQoL-8D utility value was 0.76 (0.17) and median 0.81 (IQR 0.63–0.88). Spearman’s rank was r = 0.68; (p < 0.001); however, Bland–Altman analysis revealed fundamental differences. Neither instrument gave rise to floor effects. A ceiling effect was observed with the EQ-5D-5L, with 36 % of participants obtaining a utility value of 1.00 (perfect health). These same participants obtained a mean utility of 0.87 on the AQoL-8D, primarily driven by the mental-super-dimension score (0.52).
Conclusions
The AQoL-8D preferentially captures psychosocial aspects of metabolic/bariatric surgery patients’ HRQoL. We recommend the AQoL-8D as a preferred MAUI for these patients given their complex physical/psychosocial needs.