OBJECTIVES: Quality of life of people who use opioids regularly is associated with substantial morbidity. The current study assessed the association between utility-based quality of life and drug use, and opioid substitution therapy (OST).

METHODS: Participants were asked to answer questions about their drug history, including: frequency, type of drug use, length of drug use, OST and length of OST. The EQ-5D survey questionnaire was used to capture utility-based quality of life. Our study was registered through EUROQOL (ID: 33015). EQ-5D utility was obtained from a crosswalk index value calculator using the UK value set. The beta distribution was used to model the utilities among different groups of people who used opioids.

RESULTS: Our study included 402 participants (median age: 41 years; 63% males; 93% had history of drug injection; median length of opioid use was 22 years). At the time of the survey, 67% of participants were using OST, of which 78% used Methadone, 16% used Buprenorphine-naloxone, 6% used Buprenorphine. Nearly two thirds of the sample (64%) used OST, of which median length of OST was 4.8 years. People who never injected drugs had utility of 0.78 while people who had injected drugs had utility of 0.63; p =0.35. For people who use opioids for less than or equal to 5 years, the EQ-5D utility was 0.71, for those who use opioids more than 5 years, the EQ-5D utility was 0.62; p=0.07. People who used OST had utility of 0.78 while people who had never used OST had utility of 0.72 (the difference is statistically significant; p=0.02).

CONCLUSIONS: The analysis showed a significant improvement in utilities among people who used OST compared to those who did not use OST. However, there was no significant difference in utilities among people who have and have never injected drugs, and their length of drug use.