Impact of expanding smoke-free policies beyond enclosed public places and workplaces on children's tobacco smoke exposure and respiratory health: protocol for a systematic review and meta-analysis

What can be done to protect toddlers from air pollution: Current evidence

PROBLEM

Toddlers are more prone to exposure to widely distributed air pollution and to health damage from it. However, systematic summaries of evidence on protective behaviors against air pollution for toddlers are lacking.

OBJECTIVE

To identify currently available evidence on protective behaviors against air pollution for toddlers.

METHODS

The literature retrieval was performed in selected databases, limited from 2002 to 2022. Studies meeting the following criteria were included and praised: 1) clinical practice guideline, systematic review, expert consensus, recommended practice, randomized control test (RCT) or cohort study published in Chinese or English; 2) studies reporting effects of protective behaviors against air pollution on toddlers' health outcomes or providing recommendation on these behaviors. The evidence in the included studies was extracted, synthesized and graded for evidence summary.

RESULTS

Studies (N = 19) were used for evidence summary development and 35 pieces of best evidence were synthesized, which were divided into three categories, including "avoiding or reducing air pollution generation", "removing existing air pollution", and "avoiding or reducing exposure to existing air pollution".

CONCLUSIONS

More evidence is needed to identify protective measures against outdoor air pollution and tobacco smoke. Research in the future should focus on the safety, effectiveness and feasibility of universal measures implemented in toddlers, and try to develop protective measures specific to toddlers which highlight their special nature.

IMPLICATIONS

The results of this study can help pediatric nurses provide individualized advice and assistance for toddlers and their families, and conduct research on the effectiveness of toddler-targeting protective behaviors more efficiently.

Socio-economic inequalities in smoking and drinking in adolescence: Assessment of social network dynamics

AIMS

We investigated whether (1) adolescents selected friends with a similar socio-economic status (SES), (2) smoking and alcohol consumption spread in networks and (3) the exclusion of non-smokers or non-drinkers differed between SES groups.

DESIGN

This was a longitudinal study using stochastic actor-oriented models to analyze complete social network data over three waves.

SETTING

Eight Hungarian secondary schools with socio-economically diverse classes took part.

PARTICIPANTS

This study comprised 232 adolescents aged between 14 and 15 years in the first wave.

MEASUREMENTS

Self-reported smoking behavior, alcohol consumption behavior and friendship ties were measured. SES was measured based upon entitlement to an income-tested regular child protection benefit.

FINDINGS

Non-low-SES adolescents were most likely to form friendships with peers from their own SES group [odds ratio (OR) = 1.07, 95% confidence interval (CI) = 1.02-1.11]. Adolescents adjusted their smoking behavior (OR = 24.05, 95% CI = 1.27-454.86) but not their alcohol consumption (OR = 1.65, 95% CI = 0.62-4.39) to follow the behavior of their friends. Smokers did not differ from non-smokers in the likelihood of receiving a friendship nomination (OR = 0.98, 95% CI = 0.87-1.10), regardless of their SES. Alcohol consumers received significantly more friendship nominations than non-consumers (OR = 1.16, 95% CI = 1.01-1.33), but this association was not significantly different according to SES.

CONCLUSIONS

Hungarian adolescents appear to prefer friendships within their own socio-economic status group, and smoking and alcohol consumption spread within those friendship networks. Socio-economic groups do not differ in the extent to which they encourage smoking or alcohol consumption.

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

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.

METHODS

In 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.

FINDINGS

We 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.

FUNDING

Dutch Heart Foundation, Lung Foundation Netherlands, Dutch Cancer Society, Dutch Diabetes Research Foundation, Netherlands Thrombosis Foundation, and Health Data Research UK.