Municipal smoke-free laws and preterm birth.

BACKGROUND: Smoking during pregnancy and prenatal secondhand smoke exposure increase the risk of preterm birth. As Kentucky has the second highest rate of smoking in the United States and no statewide smoke-free law, an examination of the effect of municipal smoke-free legislation on preterm birth is warranted. OBJECTIVE: This study used state-level live birth data and county-level municipal smoke-free legislation status to assess the association between the presence and strength of smoke-free laws and the likelihood of preterm birth. Moreover, this study hypothesized that pregnant persons living in counties with comprehensive municipal smoke-free laws prohibiting smoking inside all workplaces and enclosed public places would exhibit a lower likelihood of preterm birth than those living in counties with weak or moderate laws (ie, smoke-free laws with exemptions that do not cover all workplaces and enclosed public places) or no smoke-free law. STUDY DESIGN: Using live birth data from the Kentucky Office of Vital Statistics with birth years ranging from 2004 to 2020, a total of 894,372 live births were recorded that indicated that a childbearing person was between the ages of 18 and 49 years and a resident of Kentucky; these live births formed the sample for the study. Municipal ordinances implemented during a given calendar year were coded in the model as present starting with the following calendar year, as the birth records were time deidentified except for the year of birth. This lagged law convention maximized the likelihood that pregnant persons included in the study were exposed to the smoke-free policy for at least a portion of their pregnancy. Multilevel logistic regression was used to assess the effect of smoke-free ordinances on the likelihood of preterm birth, with personal- and county-level variables included as potential covariates and pregnant persons nested within the county of residence. Data analysis was conducted using SAS (version 9.4; SAS Institute, Cary, NC), with an alpha level of .05. RESULTS: Nearly all personal-level variables were associated with preterm birth status. Personal factors associated with an increased likelihood of preterm birth included being older (relative to 18-24 years old; odds ratios [95% confidence intervals]: 1.02 [1.01-1.04] and 1.27 [1.24-1.31] for ages 25-34 and 35-49 years, respectively); having a history of preterm birth (odds ratio, 4.65; 95% confidence interval, 4.53-4.78); and smoking before pregnancy (odds ratio, 1.14; 95% confidence interval, 1.12-1.16). Pregnant persons living in counties with comprehensive laws were 9% less likely to have a preterm birth than those living in counties without a smoke-free ordinance (odds ratio, 0.91; 95% confidence interval, 0.89-0.94; P<.001). There was no difference in the likelihood of preterm birth between those living in counties with moderate or weak laws and those unprotected by any smoke-free ordinance in their county of residence. CONCLUSION: This study demonstrated that comprehensive municipal smoke-free laws are associated with reduced risk of preterm birth and that moderate or weak smoke-free laws are not. The findings have major implications for public health policy and underscore the potential influence of healthcare providers' advocacy for strong smoke-free policies, prohibiting smoking in all workplaces (including restaurants, bars, and casinos), to support healthy pregnancies.

Electronic cigarette liquid and device parameters and aerosol characteristics: A survey of regular users.

INTRODUCTION: Electronic cigarettes are widely variable devices, typically with user definable liquid and device parameters. Yet, little is known about how regular users manipulate these parameters. There is also limited understanding of what factors drive electronic cigarette use and liquid purchasing, and whether two common ingredients, propylene glycol and vegetable glycerin, alter the subjective effects of these devices. METHODS: During the spring of 2016 522 adults, who reported daily use of electronic cigarettes containing nicotine, completed a survey on electronic cigarettes. Survey questions included an electronic cigarette dependence questionnaire, questions on tobacco and electronic cigarette use, and device and liquid preferences. RESULTS: Fifty-nine percent of respondents reported using another tobacco product, which was positively associated with level of nicotine dependence. On average, devices were set to 28.3 (SD = 24.2) watts. Ability to change device voltage, and level of resistance typically used, was significantly associated with level of nicotine dependence. Amount of liquid consumed, nicotine concentration, and milligrams of nicotine used per week, were positively associated with nicotine dependence. Participants rated 'good taste' as the most important consideration when using and purchasing liquids, and propylene glycol is associated with undesirable effects and vegetable glycerin with desirable effects. CONCLUSIONS: These data indicate that electronic cigarette users utilize a wide range device parameter settings and liquid variables, and that individuals with greater nicotine dependence favor voltage control devices, and lower resistance heating elements. Taste is a key factor for electronic cigarette selection, and concentrations of propylene glycol and vegetable glycerin may have a significant impact on the reinforcing effects of liquids.