Quality of Life in Opioid Replacement Therapy: A Naturalistic Cross-Sectional Comparison of Methadone/Levomethadone, Buprenorphine, and Diamorphine Patients

Background: Research on quality of life (QoL) of chronically ill patients provides an opportunity to evaluate the efficacy of long-term treatments. Although it is established that opioid replacement therapy is an effective treatment for opioid-dependent patients, there is little knowledge about physical and psychological functioning of QoL for different treatment options. Objectives: Altogether, 248 opioid-dependent patients receiving substitution treatment with either methadone/levomethadone ( n = 126), diamorphine ( n = 85), or buprenorphine ( n = 37) were recruited in 6 German therapy centers. Methods: Sociodemographic data were collected. QoL – physical and psychological functioning – for different substitutes was assessed using the Profile of the Quality of Life in the Chronically Ill (PLC) questionnaire. Results: Patient groups were similar regarding age and duration of opioid dependence. Employment rate was significantly higher ( p < 0.005, φ = 0.22) in the buprenorphine group (46%) compared to methadone (18%). Dosage adjustments were more frequent ( p < 0.001, φ = 0.29) in diamorphine (55%) than in methadone (30%) or buprenorphine (19%) patients. Buprenorphine and diamorphine patients rated their physical functioning substantially higher than methadone patients ( p < 0.001, η 2 = 0.141). Diamorphine patients reported a higher psychological functioning ( p < 0.001, η 2 = 0.078) and overall life improvement ( p < 0.001, η 2 = 0.060) compared to methadone, but not compared to buprenorphine patients (both p > 0.25). Conclusion: Measurement of important QoL aspects indicates significant differences for physical and psychological functioning in patients receiving the substitutes methadone/levomethadone, diamorphine, and buprenorphine. This could be relevant for the differential therapy of opioid addiction.