Effect of smoke-free policies in outdoor areas and private places on children's tobacco smoke exposure and respiratory health: a systematic review and meta-analysis

Abstract

Background Smoke-free policies in outdoor areas and semi-private and private places (eg, cars) might reduce the health harms caused by tobacco smoke exposure (TSE). We aimed to investigate the effect of smoke-free policies covering outdoor areas or semi-private and private places on TSE and respiratory health in children, to inform policy. MethodsIn this systematic review and meta-analysis, we searched 13 electronic databases from date of inception to Jan 29, 2021, for published studies that assessed the effects of smoke-free policies in outdoor areas or semi-private or private places on TSE, respiratory health outcomes, or both, in children. Non-randomised and randomised trials, interrupted time series, and controlled before-after studies, without restrictions to the observational period, publication date, or language, were eligible for the main analysis. Two reviewers independently extracted data, including adjusted test statistics from each study using a prespecified form, and assessed risk of bias for effect estimates from each study using the Risk of Bias in Non-Randomised Studies of Interventions tool. Primary outcomes were TSE in places covered by the policy, unplanned hospital attendance for wheezing or asthma, and unplanned hospital attendance for respiratory tract infections, in children younger than 17 years. Random-effects meta-analyses were done when at least two studies evaluated policies that regulated smoking in similar places and reported on the same outcome. This study is registered with PROSPERO, CRD42020190563. FindingsWe identified 5745 records and assessed 204 full-text articles for eligibility, of which 11 studies met the inclusion criteria and were included in the qualitative synthesis. Of these studies, seven fit prespecified robustness criteria as recommended by the Cochrane Effective Practice and Organization of Care group, assessing smoke-free cars (n=5), schools (n=1), and a comprehensive policy covering multiple areas (n=1). Risk of bias was low in three studies, moderate in three, and critical in one. In the meta-analysis of ten effect estimates from four studies, smoke-free car policies were associated with an immediate TSE reduction in cars (risk ratio 0•69, 95% CI 0•55-0•87; 161 466 participants); heterogeneity was substantial (I² 80•7%; p<0•0001). One additional study reported a gradual TSE decrease in cars annually. Individual studies found TSE reductions on school grounds, following a smoke-free school policy, and in hospital attendances for respiratory tract infection, following a comprehensive smoke-free policy. Interpretation Smoke-free car policies are associated with reductions in reported child TSE in cars, which could translate into respiratory health benefits. Few additional studies assessed the effect of policies regulating smoking in outdoor areas and semi-private and private places on children's TSE or health outcomes. On the basis of these findings, governments should consider including private cars in comprehensive smoke-free policies to protect child health.

Association between percentage of smokers and prevalence of smoking attributable morbidity in Indonesia: one decade after implementation of smoke-free area regulation

“…Smoke Free Area regulation is one of the government’s efforts to control diseases caused by smoking and exposure to cigarette smoke in the environment. A meta-analysis research shows that smoke free area regulation as implementation of WHO’s recommended tobacco control policies (MPOWER) was associated with substantial benefits to health especially on perinatal and children health, especially who got in tobacco smoke exposure [ 13 , 14 ]. The WHO MPOWER recommendation were able to reduce the adult daily smoking prevalence significantly the countries with higher initial tobacco control preparedness and higher smoking burden [ 15 ].…”

Protecting children from tobacco-related harm in private vehicles

“…9,10 Protecting children from the harmful effects of tobacco smoke exposure is essential and regulating smoking in cars is important given the extremely high levels of toxins. Alongside existing studies showing that these measures can reduce tobacco smoke exposure inside cars, 8 the Scottish study provides further impetus to accelerate implementation of similar policies across the globe. Such policies should be part of a comprehensive approach to tobacco control, which includes smoke-free policies covering public places and workplaces if not already in place.…”

“…Márta Radó and colleagues' systematic review identified five quasi-experimental studies on the links between smoke-free car policies and children's tobacco smoke exposure, with only one study reporting health outcomes. 8 Meta-analysis of ten estimates from four of these studies found an immediate 31% (95% CI 13-45) reduction in children's tobacco smoke exposure inside vehicles, but the low number of studies precluded examination of subgroup effects, and there was little consideration of links with hard clinical outcomes in individual studies. Mackay and colleagues 6 address these gaps in the evidence base.…”

Healthcare Professionals’ Knowledge, Attitudes and Counselling Practice Regarding Prevention of Secondhand Smoke Exposure Among Pregnant Women/Children in Assiut, Egypt

“…The prevalence of SHS exposure among women in reproductive age (15–49 years) in Egypt is estimated to be 65% [ 11 ], and about 50% of pregnant non-smoking women in Egypt are exposed daily to SHS [ 12 ] compared to 29% of non-smoking adults in European Union [ 13 ]. Pervious evidence reported significant relation between SHS exposure reductions on public places as school and in private places as cars and lower hospital admissions due to respiratory illness among children, following a comprehensive smoke-free policy [ 14 ]. In 2014, 35% of Egyptian school students (aged 13–15) were exposed to SHS at home and 55% in enclosed public places [ 15 ].…”