We evaluated the impact of the 24/7 program in the US state of Montana.
The US state of South Dakota's 24/7 Sobriety Program (24/7) requires individuals charged or convicted of alcohol-involved offenses to avoid alcohol and submit to twice-daily or continuous alcohol testing. Using data from everyone in Montana who was convicted of their second driving under the influence (DUI) offense from 2009 to August 2013, we described program violations among 24/7 participants and then estimated the effect of 24/7 participation on the probability of DUI re-arrest. To address potential selection issues related to individual-level 24/7 participation, we used an instrumental variables approach that exploits county-level variation in program adoption. Among 2768 people convicted of a second DUI in our analytical sample, 356 participated in 24/7 and were monitored for an average of 173 days (median = 112 days). Among the 332 participants monitored by breath test, 95.5% of scheduled alcohol breath tests were completed and did not lead to a program violation. After controlling for individual- and community-level covariates as well as year and county fixed effects, our instrumental variable models suggested that participation in 24/7 reduced the 1-year DUI re-arrest probability by at least 80% (preferred model: 86% decrease; 8.9 percentage points) compared with a counterfactual group of people convicted of a second DUI over the same period but not assigned to the program. South Dakota USA's 24/7 Sobriety Program appears to work in Montana as well. Certain delivery of immediate but modest sanctions for repeat driving under the influence (DUI) arrestees who violate alcohol abstinence orders appears to be able to reduce future DUI arrests. (Publisher Abstract)