Retention in Georgia opioid substitution therapy program and associated factors.

Background: Substance abuse has been considered as a growing challenge in Georgia that is closely linked with human immune deficiency virus (HIV) and hepatitis C transmission due to unsafe injection and other uncontrolled behaviors. Methadone maintenance therapy is one of the major treatment options for opioid-dependent individuals. It has proven efficacy in decreasing illegal opioid consumption and criminal behavior as well as reducing the level of HIV infection, mortality, HCV infection, and increasing social functioning.

Methods: The data was initially extracted from the electronic database, as of October 30, 2015, for the patients undergoing methadone maintenance therapy in 2014 and 2015. We used two types of statistical analysis: binary regression and time-to-event analysis (Kaplan-Meier). For binary regression analysis, patients who initiated the treatment 12, 9, 6, and 3 months prior to October 30, 2015, respectively, were eligible for >12-, >9-, >6-, and >3-month retention analysis. We identified two types of the retention periods: (I) "the program specific retention period" (the time spent (uninterruptedly) in the Global Fund to Fight HIV/AIDS, Tuberculosis, and Malaria (GFATM) opioid substitution treatment (OST) program after the clients' last entry) and (II) "being on OST retention period" (the time spent (uninterruptedly) on OST since the clients' last entry). For time-to-event analysis, the two different endpoints were investigated: (i) dropouts and (ii) being detained.

Results: The analysis showed that at each time point, "being on OST retention" rates are slightly higher than "program specific retention" rates. The percentages of patients retained in OST treatment after 3, 6, 9, and 12 months from the initiation of the treatment, respectively, were 89, 86, 85, and 83% and the percentages of patients retained in the GFATM program at the same time points were 88, 83, 82, and 80%. Patients older than 40 years are twice as likely to stay in the program compared to younger individuals. Gender is only associated with >9 and >12 months retention with approximately three times the odds for men compared to women. The strength of the association between hepatitis C status and "program specific" retention increases with time spent in the program as p values decrease from 0.07 for >3- and >6-month retention to 0.01 for >9- and >12-month retention. The younger age group was more likely to get dropouts and be detained. HIV status and social status did not show statistically significant association with retention.

Conclusions: These findings identify the need for more support for younger patients as they are more vulnerable to dropouts and detention compared to the older age group, especially during the early stage of treatment.