The role of age and opioid agonist treatment on substance use treatment completion in the United States.

Background: There is a large body of research indicating that substance use disorder treatment completion leads to higher rates of sustained recovery. However, not much is known about how age and opioid treatment programs (OTPs) OTPinteract to affect treatment completion. The purpose of this article is to better understand the pathway between age, OTP, and treatment completion.

Methods: Data from the US 2017 Treatment Episodes Data Set was analyzed. Seemingly unrelated bivariate probit regression was used to determine whether OTP access mediates the relationship between age and treatment completion. We used propensity score matching to simulate the effects of a randomized control trial and to attenuate the likelihood of a Type 1 error.

Results: Older adults have a higher likelihood than their younger counterparts of completing treatment regardless of OTP status in inpatient and outpatient settings. Those who received OTP in inpatient treatment had a 45% increased probability of completing treatment in detox settings and a 41% increased probability of completing treatment in inpatient settings. Older adults (age 50+) were more likely to receive OTP than their younger counterparts. There is a small but significant indirect effect of age on treatment completion in inpatient settings.

Conclusions: Older adults are more likely to receive OTP in both inpatient and outpatient settings. However, age does not appear to affect the probability of treatment completion when individuals receive OTP, except in inpatient settings. Implications are discussed.