Smokers who can no longer light up at work or public spaces due to comprehensive smoke-free bans do not appear to be compensating by smoking more at home in the presence of their children, a new study finds.
Comprehensive smoking bans have proliferated in recent years and have been shown to be highly effective in reducing secondhand smoke exposures in work and public spaces.
But the success of the bans made Robert Wood Johnson Foundation economist and researcher Kerry Anne McGeary, PhD, and colleagues wonder if the laws could be causing inadvertent harm to children and infants if smokers are lighting up more at home.
“Economists like to study not only the intended consequences of laws and policies, but also the unintended consequences,” McGeary told MedPage Today. “We have a lot of evidence that these bans reduce secondhand smoking exposures among adults and improve health outcomes, even among nonsmokers. But we don’t have a lot of information to tell us if people are smoking more at home to compensate. That is a difficult thing to measure.”
In an effort to examine the impact of local and statewide comprehensive smoke-free laws on at-home secondhand smoke exposures among children and infants, the team analyzed two restricted, nationally representative datasets — the U.S. Vital Statistics Natality Data network and the National Health Interview Surveys (NHIS).
Their findings were published in the National Bureau of Economic Research Bulletin on Aging and Health.
“Each dataset offers unique advantages, is nationally representative, and has a large sample size, allowing us to maximize statistical power and assess differential effects across socio-demographic factors,” the researchers wrote.
Individual birth records from the U.S Vital Statistics Natality files were used to assess the impact of smoke-free laws on infants.
Detailed information on all individual births occurring in the 50 states and D.C. are submitted by hospitals to state vital registration offices, which is then reported to the National Center for Health Statistics (NCHS). Information on each birth includes the date and place of birth, along with the demographic characteristics of the mother and father such as age, race, education, marital status, parity, and whether born in the U.S.
For the analysis, the researchers included birthweight and gestation data from 1990 through 2012, representing 86.3 million U.S. births: “This period enveloped the first 100% smoke-free laws in three municipalities in California to the proliferation of these bans over the next 2 decades, when almost 900 municipalities enacted a 100% smoke-free law in at least one venue and almost two-thirds of the U.S. population were exposed.”
Data from the NHIS spanning 1998 through 2013 were analyzed to assess the effect of smoking bans on child health. The analysis included data on 167,328 children under the age of 18. NHIS surveys included information on the smoking status of parents and other household members.
Information on smoking bans over time was identified through a 100% smoke-free law dataset compiled by the American Nonsmokers’ Rights Foundation.
When areas with comprehensive smoking bans in workplaces, restaurants, and bars were compared with areas with partial or no bans at all, the analysis revealed that gestational periods were longer and low-birth weight deliveries were reduced in the comprehensive smoke-ban locations.
Markers were seen among children living in the comprehensive smoke-free locations for improvements in respiratory health, such as reductions in asthma, allergies, asthma attacks, emergency department visits, and having three or more ear infections.
These effects were statistically significant, and the greatest improvements were seen among the children who were most at risk, including those living in low-income homes and with parents without college educations.
“We do not find any evidence that adults are shifting their smoking behaviors to inside the home where children may be present,” the researchers wrote. “If anything, we find significant evidence of a decrease in the likelihood that smoking occurs inside the home among households with children, consistent with an overall reduction in the additive stock and an overall reduction in smoking behavior.”
McGeary said it is possible that comprehensive smoke-free bans have helped to educate smokers about the dangers of secondhand smoke, making it less likely that they will light up at home around their children.
“When seat-belt laws were enacted, people began to change their driving behaviors. The laws conveyed the information that driving is a risky thing to do. We may be seeing something similar with regard to behavioral response to smoke-free laws. People are changing their thinking about whether it is OK to smoke around children.”
Grant funding for the research was provided by the National Cancer Institute.
The authors note that National Bureau of Economic Research working papers are circulated for discussion and comment and have not been peer reviewed.
F. Perry Wilson, MD, MSCE Assistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner