Change in Quality of Life and Its Predictors in Heroin Users Receiving Methadone Maintenance Treatment in Taiwan: An 18-Month Follow-Up Study

Abstract

Background: A good quality of life (QOL) is associated with successful treatment in patients with opioid dependence. Therefore, it is of clinical benefit to examine what factors can predict a change in QOL among heroin users in the course of a methadone maintenance treatment (MMT) program. Objectives: This longitudinal study aimed to examine the patterns and predictors of change in QOL among heroin users during the period of an 18-month MMT program. Methods: A total of 368 intravenous heroin users receiving MMT in southern Taiwan between 2007 and 2008 were interviewed using the Taiwan version of the Brief Version of the World Health Organization Quality of Life Instrument (WHOQOL-BREF) at baseline and after 3, 6, 9, 12, 15, and 18 months of treatment. Demographic and substance-use characteristics, severity of heroin use, HIV serostatus, criminal record, and family function data were collected during baseline interviews. Data on methadone dosage at each follow-up point and the duration of retention in the MMT program were also collected. Results: Improvement in QOL was rapid during the first 3 months after initiation of MMT and slowed beyond the 3-month point. A higher dosage of methadone predicted a better QOL. In addition, longer retention in the program may be associated with a better QOL. Conclusions: The results supported the hypothesis that, regarding QOL, heroin users can benefit rapidly and continuously from a MMT. A higher dose of methadone and longer treatment may predict improvement in QOL. Scientific significance: Efforts are needed to amend the modifiable factors related to poor QOL for heroin users in MMT programs.