Effects of Smoke-Free Laws on Alcohol-Related Car Crashes in California and New York: Time Series Analyses From 1982 to 2008

摘要

We examined effects of New York and California’s statewide smoke-free restaurant and bar polices on alcohol-related car crash fatalities. We used an interrupted time-series design from 1982 to 2008, with 312 monthly observations, to examine the effect of each state’s law on single-vehicle-nighttime crashes and crashes involving a driver with a blood alcohol concentration of 0.08 grams per deciliter or greater. Implementation of New York and California’s statewide smoke-free policies was not associated with alcohol-related car crash fatalities. Additionally, analyses showed no effect of New York’s smoke-free policy on alcohol-related car crash fatalities in communities along the Pennsylvania-New York border. Statewide smoke-free restaurant and bar laws do not appear to affect rates of alcohol-related car crashes. Restricting smoking in public places has become an essential component of tobacco control worldwide. Smoke-free policies reduce secondhand smoke exposure, 1–6 and may have other important public health benefits including reducing opportunities to smoke, changing smoking norms, and reducing smoking rates. 7–10 Despite beneficial public health effects of smoke-free policies, a specific study has raised the possibility of serious deleterious side effects of smoke-free laws on alcohol-related car crashes. Using jurisdictions that implemented smoking bans between 2000 and 2005, Adams and Cotti found that smoke-free bars in the United States were associated with a 13% increase in annual traffic fatalities involving drivers with a blood alcohol content (BAC) of 0.08 grams per deciliter or greater. 11 There are several plausible mechanisms by which alcohol-related traffic crashes might increase or decrease as a result of smoke-free restaurant and bar laws. First, studies suggest that policies that reduce smoking may also reduce alcohol consumption and related problems. In economic terms, alcohol and tobacco appear to be complements. 12 Dee, for example, showed that higher cigarette taxes were associated with reductions in adolescent alcohol use. 13 Smoke-free laws may also increase the number of restaurant or bar patrons that are nonsmokers and decrease the number of patrons that are smokers. This change in patronage may lead to an overall reduction in alcohol use because nonsmokers are less likely to drink alcohol than are smokers, and also less likely to be heavy drinkers. 14 Smoke-free laws, however, are not universal, and as such, patrons may travel further distances to patronize bars that do allow smoking (perhaps across a jurisdictional border to another city or state). 11 Because the majority of smoke-free laws occur at the local and state levels, driving to another restaurant or bar that is not bound by a smoke-free law, or that has outdoor seating, is feasible in many situations. Because smokers are more likely to be drinkers, cross-border shopping could result in intoxicated individuals driving greater distances, increasing crash risk exposure, resulting in a greater number of alcohol-related crashes and fatalities. The present study addresses the dearth of studies in the literature by examining the possible unintended consequences of smoke-free laws on alcohol-related car crashes. To date, only 1 study has examined this relationship and showed a 13% increase in alcohol-related fatal crashes associated with smoke-free bar policies. 11 This study, however, has several important limitations. First, states that enacted smoke-free policies prior to 2000, which provide the longest follow-up periods, were omitted from the study. Second, despite aggregating alcohol-related car crash data for each county annually, counties remained with no alcohol-related fatal traffic crashes and were omitted from the analysis. Finally, both local and statewide smoke-free policies were included and it is possible that the effects of these policies on alcohol-related car crashes differ. The present study addresses these limitations by examining the effects of smoke-free laws in the first 2 large states that passed 100% statewide smoke-free restaurant and bar laws in the United States—California and New York. Given the widespread prevalence of statewide smoke-free policies, it is important to assess potential unintended consequences of smoke-free policies on alcohol-related traffic fatalities.