TY - JOUR
T1 - A complier average causal effect analysis of the Stimulant Reduction Intervention using dosed exercise study
AU - Carmody, Thomas
AU - Greer, Tracy L.
AU - Walker, Robrina
AU - Rethorst, Chad D.
AU - Trivedi, Madhukar H.
N1 - Funding Information:
This work was supported by the National Institute on Drug Abuse of the National Institutes of Health [Award Number U10DA020024 and UG1DA020024 (PI: Trivedi)]. Additional grant support was provided by NIMH [ K01 MH097847 (PI: Rethorst)]. The content is solely the responsibility of the authors and does not represent the official views of the National Institutes of Health. Funders/sponsors had no role in study design; the collection, analysis and interpretation of data; the writing of the report; or the decision to submit the article for publication.
Publisher Copyright:
© 2018
PY - 2018/6
Y1 - 2018/6
N2 - Objective: 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. Method: The STimulant use Reduction Intervention using Dosed Exercise study was a randomized controlled trial comparing a 12 kcal/kg/week (KKW) exercise dose versus a health education control conducted at nine 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 13.0 (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-reported TimeLine Follow Back and urine drug screen results. Results: The CACE-adjusted analysis found a significantly lower probability of relapse to stimulant use in the exercise group versus the health education group (41.0% vs. 55.7%, p <.01) and significantly lower days of stimulant use among those who relapsed (5.0 days vs. 9.9 days, p <.01). Conclusions: The CACE adjustment revealed significant, positive effects for exercise. 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.
AB - Objective: 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. Method: The STimulant use Reduction Intervention using Dosed Exercise study was a randomized controlled trial comparing a 12 kcal/kg/week (KKW) exercise dose versus a health education control conducted at nine 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 13.0 (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-reported TimeLine Follow Back and urine drug screen results. Results: The CACE-adjusted analysis found a significantly lower probability of relapse to stimulant use in the exercise group versus the health education group (41.0% vs. 55.7%, p <.01) and significantly lower days of stimulant use among those who relapsed (5.0 days vs. 9.9 days, p <.01). Conclusions: The CACE adjustment revealed significant, positive effects for exercise. 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.
KW - Clinical trials network
KW - Complier average causal effects
KW - Exercise intervention
KW - Health education
KW - Stimulant abuse or dependence
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U2 - 10.1016/j.conctc.2018.02.001
DO - 10.1016/j.conctc.2018.02.001
M3 - Article
C2 - 29682627
AN - SCOPUS:85042701243
SN - 2451-8654
VL - 10
SP - 1
EP - 8
JO - Contemporary Clinical Trials Communications
JF - Contemporary Clinical Trials Communications
ER -