Effectiveness of ignition interlock devices in reducing drunk driving recidivism.

OBJECTIVE: To determine if ignition interlock devices reduce driving while intoxicated (DWI) recidivism. SEARCH STRATEGIES: Cochrane Collaboration search strategies were used. SELECTION CRITERIA: Studies for selection examined the effectiveness of interlock programs in a defined population. Studies were required to have a clear description of the program and outcomes evaluated, to have a comparison group and to provide interpretable data. DATA COLLECTION AND ANALYSIS: A total of 31 studies were found. Ten studies met the selection criteria. Three of these studies were eliminated from further analysis because they did not contain original data. A fourth study was eliminated due to methodologic weaknesses, leaving six studies for final review and analysis. Pooled analyses were not done because studies did not follow similar methods over comparable time periods. MAIN
RESULTS: Five of the six studies found interlocks were effective in reducing DWI recidivism while the interlock was installed in the car. In the five studies demonstrating a significant effect, participants in the interlock programs were 15%-69% less likely than controls to be re-arrested for DWI. The only reported randomized, controlled trial demonstrated a 65% reduction in re-arrests for DWI in the interlock group, compared with the control group.
CONCLUSIONS: Alcohol ignition interlock programs appear to be effective in reducing DWI recidivism during the time period when the interlock is installed in the car. Future studies should attempt to control for exposure (i.e., number of miles driven) and determine if certain sub-groups are most benefited by interlock programs.