Evaluation of traffic injury prevention programs using counting process approaches

Abstract

Traumatic brain injury (TBI) is among the most devastating of injuries leading to death and disability among young people today. The major cause of TBI is motor vehicle crashes. One way to reduce the rates of such crashes and thus TBI is through prevention programs. This article analyzes a study conducted for assessing a 1-day educational traffic injury prevention program for young traffic offenders with speeding violations. The obtained data include information about traffic convictions for speeding violations on a group of 16- to 23-year-old drivers. A common method for analyzing such studies is to use simple two-sample rank tests on summary statistics. But this approach ignores the detailed conviction process information and can assess only the long-term overall effect of the program. In this article, we treat the data as recurrent event data and apply a novel approach based on counting processes to evaluate the program. Our approach makes use of the information ignored by the rank tests and allows the assessment of both short- and long-term effects of the program. The analysis results indicate that the prevention program has an effect for a short period and suggest that a long-term effect could be gained if the program is repeated.