The evaluation of a workplace program to prevent substance abuse: Challenges and findings (2016)

Workplace consequences of alcohol and drug abuse include poor performance, fighting, insubordination, and occupational injuries. To address the need for workplace substance abuse prevention, the PREVENT program, originally designed for the United States Navy, was adapted to the railroad workforce. This study evaluates the impact of the PREVENT program on alcohol use and smoking among young adults ages 18-29 in the railroad industry. We discuss challenges to study protocol faced by this evaluation in the reality of the workplace. PREVENT is a 2-day health promotion program that includes substance abuse and smoking modules. Using a prospective controlled before-after study design, we compare self-reported alcohol use and smoking pre-versus post-intervention among PREVENT participants versus a comparison group of workers. Comparison and case group non-equivalency at baseline is controlled for using a propensity score. The study sample suffered high losses to follow-up. In the analysis, we included those lost to follow up and applied an intent-to-treat approach that assumed, conservatively, that substance use by non-respondents was identical pre and post. In regression analysis PREVENT participants showed significant declines in drinking levels post-intervention compared to comparison workers, controlling for baseline and demographic factors. Relative to pre-intervention levels PREVENT participants consumed 56 % fewer drinks (relative rate = 0.44, 95 % CI 0.23-0.85) and consumed alcohol on 32 % fewer days (relative rate = 0.68, 95 % CI 0.50-0.93) compared to comparison workers. Changes in smoking behaviors were not significant. We conclude that PREVENT is a promising program for reducing alcohol abuse.