Health-related quality of life of patients on opiate replacement therapy

Background. Substance misuse poses a huge health burden worldwide. Individuals who misuse drugs have higher rates of morbidity and mortality. It has been widely documented that health-related quality of life (HRQOL) is lower in people who misuse drugs, particularly intravenous drug users (IDU), than in the general population. Aim. To evaluate HRQOL and contributing factors in individuals receiving opiate replacement therapy. Methods. This was a cross-sectional study of patients attending for methadone therapy in an inner city drug treatment centre. EQ-5D, SF-36, SF-6D, Hospital Anxiety Depression Scale (HADs) were assessed, along with substance abuse via the Treatment Outcomes Profile (TOPs). Mean values, ranges and standard deviations were calculated and utility scores were derived. Statistical relationships between HRQOL and other variables were explored using univariate and multivariate analysis. Results: 115 patients were included, 72% were male and the mean age was 35 years. 63% were HCV-PCR positive and 49% admitted to using drugs in the past month. 57% of patients had high levels of anxiety with the mean score being 11.14 (anxious). 35% were depressed with the mean score being 8.40 (borderline depressed). The mean EQ-5D utility score was 0.56 with 7% having a utility score that was 'worse than death'. The mean SF-36 utility score was 0.55. The mean SF-36 physical component score was 44.25 and the mean mental component score was 33.18. Anxiety and depression were significantly correlated with EQ-5D and SF-6D utility values on both univariate and multivariate analysis. Conclusion: HRQOL was reduced in this opiate replacement therapy cohort with only anxiety and depression having a significant impact.