Longitudinal Associations of Smoke-Free Policies and Incident Cardiovascular Disease : CARDIA Study

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d6915268e173">Background</h5> <p id="P1">Smoke-free legislation has been associated with lower rates of cardiovascular disease hospital admissions in ecologic studies. However, prior studies lacked detailed information on individual-level factors (e.g. socio-demographic and clinical characteristics) that could potentially confound associations. Our objective was to estimate associations of smoke-free policies with incident cardiovascular disease in a longitudinal cohort after controlling for socio-demographics, cardiovascular disease risk factors, and policy covariates. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d6915268e178">Methods</h5> <p id="P2">Longitudinal data from 3,783 black and white adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study (1995-2015) were linked to state, county and local 100% smoke-free policies in bars, restaurants, and non-hospitality workplaces by census tract. Extended Cox regression estimated hazard ratios (HRs) of incident cardiovascular disease associated with time-dependent smoke-free policy exposures. Models were adjusted for socio-demographic characteristics, cardiovascular disease risk factors, state cigarette tax, participant-reported presence of a smoking ban at their workplace, field center, and metropolitan statistical area poverty. </p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d6915268e183">Results</h5> <p id="P3">During a median follow-up of 20 years (68,332 total person-years), 172 participants had an incident cardiovascular disease event (2.5 per 1,000 person-years). Over the follow-up period, 80% of participants lived in areas with smoke-free policies in restaurants, 67% in bars, and 65% in non-hospitality workplaces. In fully adjusted models, participants living in an area with a restaurant, bar, or workplace smoke-free policy had lower risk of incident cardiovascular disease compared to those in areas without smoke-free policies (HR: 0.75, 95% CI: 0.49, 1.15; HR: 0.76, 95% CI: 0.47, 1.24; HR: 0.54, 95% CI: 0.34, 0.86, respectively; HR 0.58, 95% CI: 0.33, 1.00 for living in an area with all 3 types of policies compared to none). The estimated preventive fraction was 25% for restaurant policies, 24% for bar policies, and 46% for workplace policies. </p> </div><div class="section"> <a class="named-anchor" id="S4"> <!-- named anchor --> </a> <h5 class="section-title" id="d6915268e188">Conclusions</h5> <p id="P4">Consistent with prior ecologic studies, these individual-based data add to the evidence that 100% smoke-free policies are associated with lower risk of cardiovascular disease among middle-aged adults. </p> </div>