Abstract
BACKGROUND: Intervention adherence and trial retention are challenging for clinical trials testing intensive behavioral interventions. Operational constraints or trial designs may preclude using effective retention strategies such as financial incentives. We examined whether implementing pre-enrollment orientation sessions was associated with higher intervention adherence and retention in a pragmatic clinical trial. METHODS: The trial tested an intensive behavioral intervention for patients with chronic pain on long-term opioids. Orientation sessions were implemented two years into trial recruitment at one site. Held before informed consent and randomization, these mandatory, group-based orientation sessions provided trial specifics, explained research methods principles, and leveraged motivational interviewing techniques. Using a pre-post design and multivariate models, we assessed adherence (number of intervention meetings attended) and retention (completed quarterly pain assessments over 12 months) before (04/2014-12/2015; n = 209) and after (01/2016-02/2017; n = 258) implementation. Also, we evaluated whether session implementation affected the proportion and characteristics of enrolled patients. RESULTS: After implementing orientation sessions, patients had higher intervention adherence than before (M = 7.6, SD = 3.8 vs. M = 5.6, SD = 4.5, respectively; mean difference = 2.0, 95% CI [0.9, 3.2], p = .001), and 2.8 times greater odds of completing quarterly assessments (95% CI [1.3, 5.8], p = .007). Fewer patients enrolled after implementing sessions than before (38.1% vs. 70.8%, 95% CI [26.4, 39.1], p < .001), with no differences in patient characteristics. CONCLUSIONS: Implementing orientation sessions during recruitment may be useful for promoting trial adherence and retention. To ensure enrollment goals are met, target population size and barriers affecting patients' ability to attend orientation sessions should be considered, especially for patients with complex medical conditions. CLINICAL TRIALS REGISTRATION NUMBER: NCT02113592.