Miller, TR (2007) Effectiveness and benefit‐cost of peer‐based workplace substance abuse prevention coupled with random testing.
Country	US
Aim	Estimate the effectiveness and benefit‐cost ratio of a peer‐based substance abuse prevention program at a U.S. transportation company, implemented in phases from 1988 to 1990.
Target population	Occupation: Transportation and storage/mixed
	Industry: H—Transporting and storage
	Setting: 060 Public area
	Firm size: 250+(large)
Study design	ITS with comparison conditions: 3. Serial measures with external control
	Unit of analysis: Group/organizational level
	Sample size: 26,000 employees in company ‐‐ not provided overtime
Type of intervention	3.3 Multifaceted across individual and organizational levels
Evaluation design	Duration of intervention: implemented in phases from 1988 to 1990 and then drug testing federal mandate in 1994
	Duration of follow‐up: 4 = Long‐term (>36 months)
	Type of outcome measure: Injury
Study quality	Moderate quality