Contemporary Clinical Trials Communications 2018 (in press). [doi: 10.1016/j.conctc.2018.02.001]
Thomas Carmody, PhD, Tracy L. Greer, PhD, N. Robrina Walker, PhD, Chad Rethorst, PhD, Madhukar H. Trivedi, MD (all from University of Texas Southwestern Medical Center, TX Node).
Exercise is a promising treatment for substance use disorders, yet an intention-to-treat analysis of a large, multi-site study found no reduction in stimulant use for exercise versus health education. Exercise adherence was sub-optimal, therefore secondary post-hoc complier average causal effects (CACE) analysis was conducted to determine the potential effectiveness of adequately dosed exercise.
The STimulant use Reduction Intervention using Dosed Exercise (STRIDE) study was a randomized controlled trial comparing a 12 kcal/kg/week (KKW) exercise dose versus a health education control conducted at 9 residential substance use treatment settings across the U.S. that are affiliated with the National Drug Abuse Treatment Clinical Trials Network. Participants were sedentary but medically approved for exercise, used stimulants within 30 days prior to study entry, and received a DSM-IV stimulant abuse or dependence diagnosis within the past year. A CACE analysis adjusted to include only participants with a minimum threshold of adherence (at least 8.3 KKW) and using a negative-binomial hurdle model focused on 218 participants who were 36.2% female, mean age 39.4 years (SD=11.1), and averaged 13 (SD=9.2) stimulant use days in the 30 days before residential treatment. The outcome was days of stimulant use as assessed by the self-report TimeLine Follow Back and urine drug screen results.
The CACE-adjusted analysis found a significantly lower probability of relapse to stimulant use in the exercise group versus the health education group (41% vs. 55.7%, p<.01) and significantly lower days of stimulant use among those who relapsed (5 days vs. 9.9 days, p<.01).
Conclusions: The CACE efficacy analysis was conducted for the STRIDE study to account for exercise dose in the evaluation of exercise as a potential treatment for stimulant use disorders. This analysis demonstrated statistically significant differences for the probability of stimulant use, such that those who would achieve an adequate exercise dose (defined to be an average of 8.3 KKW or more) have an estimated lower probability of relapsing to any stimulant use. Analyses also demonstrated that, even among those who relapsed, the amount of estimated stimulant use was significantly less among those who would achieve an adequate exercise dose. Together, these results suggest a beneficial effect of exercise in the treatment of stimulant abuse. Further research is warranted to develop strategies for exercise adherence that can ensure achievement of an exercise dose sufficient to produce a significant treatment effect. (Article (Peer-Reviewed), PDF, English, 2018)
Keywords: Exercise | Relapse prevention | Statistical analysis | Stimulant abuse | Contemporary Clinical Trials Communication (journal)
Document No: 1303.
Submitted by Jack Blaine, PhD, CCTN, 2/14/2018.