This study shows that people with OUD can achieve a high treatment retention rate, cut down their use of illicit drugs, and build their recovery capital. More than half (62.2%) of the study participants were abstinent from substance use during this study, but some (37.8%) participants used opioids or other substances during the study. Continued use was not a criterion for terminating treatment. Despite relapses, over 90% of participants in this study remained in treatment for OUD at 3 months. During their treatment, participants reported significant improvements in recovery capital, fewer cravings to use opioids, and reduced use of other illicit drugs.
Treatment retention with MAT is important because it has been linked to substantial reductions in both all-cause and overdose-related mortality in people with OUD(29). Understanding what optimizes treatment retention is critical to implementing programs that are successful in keeping people in treatment. In a systematic review looking at OUD treatment retention, MAT with methadone, buprenorphine, or naltrexone was highly associated with increased treatment retention(18). In this review, retention rates across different treatment settings were extremely variable. Between 19% and 94% of people who initiated MAT for OUD remained in treatment at 3 months, with an average of 62% retained at 3 months across studies. At 92.5%, our study’s 3-month retention rate is comparable to the highest performing studies in the systematic review.
The role of psychosocial or behavioral treatment in promoting treatment retention in office-based settings is unclear, as there are few studies examining this issue and some studies have reported conflicted findings. A systematic review of 8 randomized clinical trials evaluating MAT with buprenorphine, with or without various behavioral interventions, found 4 studies showed benefit and 4 studies did not(30). Three of the four studies that found benefit used a contingency management-based intervention(31–34). While there may be some value added by offering psychosocial and behavioural treatments with MAT for OUD, and some patients may wish to incorporate these treatments into their overall care plan, current data do not support requiring its use. Our study used a patient-centered approach, whereby participants were offered psychosocial or behavioural treatments such as cognitive behaviour therapy-based group psychotherapy and peer support groups, and motivational enhancement therapy was utilized during medication management to assist with overcoming barriers to recovery, but these interventions were not a required component of treatment.
Mental illness (MI) frequently co-occurs with SUDs and is a risk factor for treatment non-completion and early departure from treatment(35). Integrating psychiatric treatment with SUD treatment leads to improved outcomes in general, and may lead to higher rates of treatment completion, compared to treating SUD and MI separately(36). For patients with OUD who are receiving MAT, MI does not appear to have a measurable impact on OUD treatment retention(37), but integrated treatment for MI and OUD improves MI treatment initiation and mental health outcomes(38). In our study, most of the MAT providers were also psychiatrists, and study participants could receive integrated treatment for co-occurring MI if needed.
Among people with a SUD, ongoing substance use is a risk factor for adverse health outcomes(39), so it stands to reason that reducing or stopping substance use would improve health. People who cut back or stop using substances have less adverse consequences of drug use such as mental health symptoms or impairment(40), have improved social and family functioning(41), and are less likely to engage in criminal behaviour(42). In a study of outcomes for people with OUD, reductions in regular heroin use were strongly associated with reductions in crime(42). Other studies have shown that reductions in cocaine use are associated with reductions in crime(43, 44). Reducing substance use has been shown to improve adolescents’ school attendance(45). Because of its positive effects on health, reducing or abstaining from substance use is a treatment target for people with OUD. In our study, 40.5% of participants reported no substance use for the past 30 days at intake, and that increased to 62.2% at 3 months. Importantly, while 30-day abstinence from substance use increased over the 3-month period, persistent substance use did not prompt treatment termination. Applying a chronic disease model approach, when symptoms persist, the appropriate response is to continue or adjust treatment, not discharge from care. Furthermore, this approach also supports treatment retention. We followed this approach, which could be part of why the retention rate is in the high end for OUD treatment.
Cravings preoccupy the mind and distract from other thoughts and activities that can strengthen recovery. Cravings are hypothesized to play a central role in relapse to opioid use(46). Reduced cravings is a primary treatment target when treating OUD, as cravings predict relapse of opioid use(47). Buprenorphine, the medication prescribed to most patients at the UI MAT clinic, has been shown to significantly reduce cravings for opioids(47). We titrated buprenorphine doses to control cravings. At intake, nearly a third of participants in our study reported no cravings to use opioids. By 3 months, the number of people reporting no cravings doubled.
Psychosocial treatments also aim to help people manage cravings by identifying and avoiding triggers that cause cravings and building skills to redirect thoughts and behaviors away from using an opioid to satisfy a craving. It is unclear to what extent reducing cravings leads to increased retention versus retention in treatment drives reductions in cravings, although both effects are likely to play a role. Our study demonstrated a reduction in cravings and a high rate of treatment retention, but it was not designed to further characterize the relationship between these two outcomes.
Another component of treatment retention is the building of recovery capital. Recovery capital includes skills and attitudes related to confidence, self-efficacy, and support system. Recovery capital predicts sustained recovery, enhances life satisfaction, and enhances ability to cope with stress [ref]. Early successes in recovery help to increase a sense of confidence in one’s ability to build their recovery. In our study, recovery capital, as measured by the ARC score, increased for most participants between intake and 3 months. Despite a decrease in the ARC score for 10 participants and a small sample size in our study, there was still a statistically significant increase in the mean ARC score overall. Over a 3-month period, our study found improvements in recovery capital, reduced cravings, and reduced substance use, all of which likely contribute to a high rate of treatment retention.
Our results should be interpreted considering this study’s limitations. All study participants received treatment for opioid use disorder, but forty percent of participants in this study reported no illicit drug use in the 30 days prior to enrollment. Some patients transferred care from another provider and were already in recovery at the time of enrollment, and some patients chose to get started in treatment and then consented to study participation later.
We measured treatment retention and other outcomes for 3 months, but as treatment retention is associated with reduced mortality(17), treatment retention should be measured in years, not months. Longer duration of treatment, however, is built on a foundation of early treatment retention.
Our study showed high rates of treatment retention at 3 months. Treatment retention in the initial months of MAT is critical to achieving higher rates of treatment retention later. Several studies have demonstrated that treatment discontinuation is highest during the first month of treatment(48, 49). Focusing on early treatment retention may help people with OUD to overcome causes of early treatment discontinuation and lead to higher rates of long-term treatment retention.
As a single-site study, reproducibility was not proven and effects sizes could be larger than those expected in a multi-site trial, but many of the components of the treatment program are widely available(50, 51) and can be replicated in other sites. Our sample does not reflect the US population, primarily because Iowa’s population is less diverse than the country’s overall. While the study population has less racial and ethnic diversity than the general population, people living in rural areas are well-represented in this study. Access to SUD treatment and MAT is a challenge in many rural communities across the country so understanding the experience of care for people living in rural communities is relevant.
This study will continue to follow patients up to 3 years. The rather small sample size of 40 reflects recruitment during the first year for this study, follow-up publications will incorporate data from the whole sample. Since our early treatment retention rate was higher than usually reported, we consider these preliminary results can contribute significantly to the OUD treatment field. Our study supports previous findings showing that evidence-based treatment (in particular MAT), offering but not requiring less proven treatment approaches (e.g., psychosocial treatment), and continuing treatment even when all treatment goals (e.g., 30-day substance use abstinence) are not met continuously can achieve high rates of success with treatment retention and other associated outcomes.
Our study demonstrates that high rates of treatment retention during the first three months of recovery are achievable. Further study is needed to determine which variables improve early treatment retention, whether these increased rates of treatment retention can be sustained during the later stages of recovery, and whether these results can be replicated in other sites and patients with different characteristics. Further disentangling the mechanisms behind optimizing recovery and treatment retention is warranted.