Factors associated with adherence to methadone treatment among heroin users attending a methadone assisted treatment program at Muhimbili National Hospital.

Abstract

Introduction Injecting drug use has resulted in major international public health problems. Estimates suggest that there are between 11-21 million individuals who inject drugs worldwide. Methadone Assisted Treatment (MAT) is becoming a more common approach to addressing the health, social, and financial ramifications of addiction. Tanzania now has an estimated 25,000 drug injectors, 40 percent of them infected with H.I.V. The main question is what factors influence one to adhere to methadone treatment. A number of previous Western studies have found evidence for a number of possible factors that may be associated with methadone treatment adherence such as age, gender, occupation, education, social relationship and support. The current study explores the extent to which these factors may be associated with adherance in a low income country with an IDU evolution and profile remarkably different from many Western countries Objectives To identify factors associated with adherence to methadone treatment among IDU attending MAT at MNH Study Design This was a retrospective cross sectional study retrieved data from clinical records. Methods This study collected data from both male and female clients who were enrolled to the methadone clinic from February 2011 to February 2013. The study analyzed data from 609 client’s files. The sample size allowed for comparison between participants who have adhered and those who had not adhered. A checklist aimed at retrieving information from clinical records (files) was developed. Questions on the checklist match with information found in the files (MAT program questionnaire) and included sociodemographics, health status (physical and mental) and psychosocial/behavioral characteristics). Data was analyzed using the SPSS version 18 Results Data from total of 632 files of clients enrolled at MNH MAT clinic was collected. Final analysis included data from 609 participant’s files with mean age (SD) of 34.28 years (6.41). The proportion of participants adhering to methadone treatment among IDUs attending MAT clinic at MNH was 75% (460) and 25% (149) did not adhere to the treatment. Bivariate analysis: There was a significant association between adherence and employment as source of income (p=0.031), results show that participants whose source of income is from employment compared to not employment are 1.5 times more likely to adhere to methadone treatment (OR, 1.50, 95% CI: 1.00-2.23). Hospitalization was another factor that showed a significant association with adherence to methadone treatment (p=0.027). Crudes odds ratio suggest that participants with a low number of hospitalization compared to no hospitalization were 49% less likely to adhere (OR, 0.51, 95% CI: 0.29-0.86) and those who had high number of hospitalization compared to no hospitalization were also less likely to adhere to methadone treatment (OR, 0.50, 95% CI: 0.29-0.87). Furthermore, incarceration showed a significant relationship with adherence (p=0.017) with crudes OR of 1.71 (95% CI: 1.08-2.72). There was also a significant relationship between quality of life and adherence (p=0.028).

Multivariate Analysis: Gender was the only factor that was found to show a significant association with adherence. Male participants compare to female were 0.24 less likely to adhere to treatment (OR, 0.24, 95% CI: 0.07-0.85).

Conclusion and Recommendations This is the first MAT in sub sahara Africa and this is the first study exploring factors that may be associated with adherence in this cultural context. It is evident from the relatively low drop out rate (25% at two year follow up) that factors that are associated with non adherence are being addressed to a great extent in the MAT programme.