Who benefits from Two Way Prayer Meditation? Treatment effect moderators in a pilot randomized controlled trial of a spiritual intervention for people with substance use disorders

Background: Two Way Prayer Meditation (TWPM) is a spiritual intervention that holds promise for improving the psychospiritual well-being of individuals in recovery from substance use disorders (SUD). This study aimed to identify moderators of TWPM's treatment effects. Moderators tested included gender, race/ethnicity, age, education, religious/spiritual affiliation, and most often used substance. Methods: This study employed a randomized controlled trial design with pretest and posttest. In total, 134 adults in four residential recovery programs participated in the study and were randomly assigned to the TWPM group or the treatment as usual control group. Linear mixed modeling was used to assess the moderating effect of each hypothesized moderator in the form of interaction tests. Sensitivity analyses were conducted by excluding cases with more than a minimum number of missing items. Results: There were no significant moderators for psychological distress, self-esteem, and most of the spiritual well-being outcomes. Both the primary and sensitivity analyses showed education significantly moderated TWPM's effect on overall spirituality self-ranking. Specifically, TWPM's positive effect on overall spirituality self-ranking was greater in the master's degree subgroup than in the less than high school subgroup. Conclusion: TWPM's treatment effects on most outcomes were not found to vary by the tested participant characteristics. The only statistically significant finding suggests clinicians may need to adjust TWPM workshop/teaching content, delivery style, or language used to reach clients with lower levels of education. Future better-powered studies are recommended to continue exploring the potential moderating effects of race/ethnicity, education, spiritual/religious affiliation, and most often used substance.