Health utility among people who regularly use opioids in Australia

Studies of health utilities among people who use opioids have mostly been based on in-treatment populations. We aim to report utility-based quality of life by participants' socio-demographic, drug and treatment characteristics, and to examine the determinants of health utility among people who use opioids regularly.

Cross-sectional study of participants who used opioids regularly, recruited across New South Wales, Victoria and Tasmania in 2018-2019. Differences in European Quality of Life (EQ-5D-5L) heath utility scores between socio-demographic and clinical subgroups were assessed using non-parametric Kruskal-Wallis test by rank. To address the unique distribution of EQ-5D-5L health utility scores in the current sample, a two-part model was applied to assess factors associated with health utility.

Among 402 participants enrolled in the study, 385 (96%) completed the EQ-5D-5L questionnaire. The mean health utility of the total sample was 0.63 (SD 0.29). Participants who previously received opioid agonist treatment [OAT] (adj marginal effect (ME) -0.11; 95% confidence interval [CI] -0.20 to -0.02) and those currently in OAT (adj ME -0.13; 95% CI -0.22 to -0.06) reported lower health utility than those who had never received OAT. Participants who used both pharmaceutical opioids and benzodiazepines had lower health utility compared to no pharmaceutical opioids and no benzodiazepines use (adj ME -0.17; 95% CI -0.28 to -0.07).

Findings provide important health utility data for economic evaluations, useful for guiding allocation of resources for treatment strategies among people who use opioids. Lower health utilities among those using benzodiazepines and pharmaceutical opioids suggests interventions targeting these subgroups may be beneficial.