An Exploratory Study: A Head-to-Head Comparison of the EQ-5D-5L and AQoL-8D for Long-Term Publicly Waitlisted Bariatric Surgery Patients Before and 3 Months After Bariatric Surgery

Background: Choice of a multi-attribute utility instrument (MAUI) that appropriately assesses an intervention’s health-related quality-of-life (HRQoL) impacts is a vital part of healthcare resource allocation and clinical assessment. Objective: Our exploratory study compared the EuroQol (EQ)-5D-5L and Assessment of Quality of Life (AQoL)-8D MAUIs, which were used to assess the effect of bariatric surgery for a cohort of long-term publicly waitlisted, severely obese patients. Methods: The study was conducted at the Hobart Private Hospital (Tasmania, Australia). To compare the sensitivity and instrument content of the two MAUIs, we used dimensional comparisons by investigating the distribution of patient-reported responses (number/percentage) across the MAUIs’ levels and dimensions; summary health-state utility valuations (utilities); and individual/super-dimension scores (AQoL-8D) to investigate discriminatory power and HRQoL improvements preoperatively and 3 months postoperatively. Results: Participants’ (n = 23) overall MAUI completion rate was 74%. Postoperative total weight loss was 9.9%. EQ-5D-5L utilities were relatively higher pre- and postoperatively than AQoL-8D utilities [mean standard deviation (SD) EQ-5D-5L 0.70 (0.25) to 0.80 (0.25); AQoL-8D 0.51 (0.24) to 0.61 (0.24)]. AQoL-8D Psychosocial super dimension was relatively low postoperatively [0.37 (0.25)], driving the instrument’s lower utility. These results were supported by the dimensional comparisons that revealed an overall greater dispersion for the AQoL-8D. Nevertheless, there were clinical improvements in utilities for both instruments. AQoL-8D utilities were lower than population norms; not so the EQ-5D-5L utilities. The AQoL-8D dimensions of Happiness, Coping, and Self-worth improved the most. Conclusions: AQoL-8D more fully captured the impact of obesity and bariatric surgery on HRQoL (particularly psychosocial impacts) for long-term waitlisted bariatric surgery patients, even 3 months postoperatively. AQoL-8D preoperative utility revealed our population’s HRQoL was lower than people with cancer or heart disease.