COPD and Strength of Smoke-free Laws

The aim is to determine the impact of strength and extent of coverage of smoke-free laws on hospitalization and mortality for chronic obstructive pulmonary disease (COPD) in Kentucky, a rural tobacco-growing state with high rates of smoking and COPD. The long-term objective is to reduce exposure to secondhand smoke (SHS) by enacting comprehensive smoke-free legislation in areas that are disproportionately affected by high smoking rates and relatively weak tobacco control laws. Southern, rural states and locales lag behind in protecting all workers from SHS. Since April 2004, 14 Kentucky communities have enacted smoke-free workplace laws with few or no exemptions (comprehensive), covering 30% of the state's total population. An additional 10 communities have implemented moderate to weak ordinances; three have smoke-free public places laws including restaurants and bars (only buildings open to the public and not all workplaces; moderate); and seven have laws covering some workplaces with significant exemptions (weak). Nine of the 24 smoke-free laws cover the entire county (complete). There are no known studies of COPD hospitalizations or mortality after enactment of smoke-free laws. A time series design will be used to analyze hospital discharges and mortality from COPD. Two methods will be developed to investigate the differential effects of smoke-free policy on COPD hospitalizations and mortality: a) the first model will determine differences in rates by the strength of the community laws (strength ranging from none [no policy] to weak [some public places and/or workplaces, with significant exemptions] to moderate [all enclosed public places with few to no exemptions] to comprehensive [all workplaces and all enclosed public places including restaurants and bars, with few to no exemptions]); and b) the second model will determine differences in COPD rates by the extent of coverage of the community laws (ranging from none [ no policy] to partial [part of the county is covered, but not all] to complete [the smoke-free policy applies to the entire county]). The Kentucky Hospital Association (KHA) hospitalization data base will be accessed for all Kentucky hospitals for a 9.5 year period, from July 2003 through December 2012. The data base will be queried for hospital discharge diagnosis by ICD-9 codes (491,492, 496), dates of service, disposition, gender, age, and county of residence. Poisson regression will be used to determine the impact of strength and extent of coverage of the law on the monthly adjusted COPD rates for each county.