Impact of a countywide smoke-free workplace law on emergency department visits for respiratory diseases: a retrospective cohort study

Evaluation of Population-Level Tobacco Control Interventions and Health Outcomes: A Systematic Review and Meta-Analysis

Importance

Smoking causes considerable noncommunicable diseases, perinatal morbidity, and mortality.

Objective

To investigate the associations of population-level tobacco-control policies with health outcomes.

Data Sources

PubMed, EMBASE, Web of Science, Cumulated Index to Nursing and Allied Health Literature, and EconLit were searched from inception to March 2021 (updated on 1 March 2022). References were manually searched.

Study Selection

Studies reporting on associations of population-level tobacco control policies with health-related outcomes were included. Data were analyzed from May to July 2022.

Data Extraction and Synthesis

Data were extracted by 1 investigator and cross-checked by a second investigator. Analyses were conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline.

Main Outcomes and Measures

The primary outcomes were respiratory system disease (RSD), cardiovascular disease (CVD), cancer, mortality, hospitalization, and health care utilization. The secondary outcomes were adverse birth outcomes, such as low birth weight and preterm birth. Random-effects meta-analysis was used to estimate pooled odds ratios (ORs) and 95% CIs.

Results

Of 4952 records identified, 144 population-level studies were included in the final analysis; 126 studies (87.5%) were of high or moderate quality. The most frequently reported policies were smoke-free legislation (126 studies), followed by tax or price increases (14 studies), multicomponent tobacco control programs (12 studies), and a minimum cigarette purchase age law (1 study). Smoke-free legislation was associated with decreased risk of all CVD events (OR, 0.90; 95% CI, 0.86-0.94), RSD events (OR, 0.83; 95% CI, 0.72-0.96), hospitalization due to CVD or RSD (OR, 0.91; 95% CI, 0.87-0.95), and adverse birth outcomes (OR, 0.94; 95% CI, 0.92-0.96). These associations persisted in all sensitivity and subgroup analyses, except for the country income category, for which a significant reduction was only observed in high-income countries. In meta-analysis, there was no clear association of tax or price increases with adverse health outcomes. However, for the narrative synthesis, all 8 studies reported statistically significant associations between tax increases and decreases in adverse health events.

Conclusions and Relevance

In this systematic review and meta-analysis, smoke-free legislation was associated with significant reductions in morbidity and mortality related to CVD, RSD, and perinatal outcomes. These findings support the need to accelerate the implementation of smoke-free laws to protect populations against smoking-related harm.

Secondhand Smoke Exposure and the Risk of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background

Many studies have shown that active smoking leads to an increasing incidence of chronic obstructive pulmonary disease (COPD). However, studies interested in the effects of secondhand smoke exposure (SHS exposure) on COPD were less or underappreciated.

Methods

A systematic review and meta-analysis was conducted to investigate the association between SHS exposure and the risk of COPD. Three databases (PubMed, Embase and Web of Science) were searched to obtain data. After assessing the study quality, stratified analyses were performed according to the region, gender, and duration of exposure. Cochran's Q and I² were utilized for heterogeneity assessment. To assess publication bias, we used a funnel plot and Egger's test.

Results

A total of 15 studies (6 cross-sectional studies, 6 case-control studies, and 3 cohort studies) with 25,592 participants were involved in this meta-analysis. This study showed that SHS exposure was associated with an increased risk of COPD (odds ratio (OR): 2.25, 95% CI: 1.40-3.62, I² = 98%, p < 0.01 for heterogeneity based on a random-effects analysis model), especially in those with a longer time exposure of more than 5 years was 4.38 (95% CI: 1.28-15.00, I² = 89%, p < 0.01 for heterogeneity based on a random-effects analysis model). In addition, SHS exposure also increases the risk of COPD in women (odds ratio (OR): 2.02, 95% CI: 1.52-2.67, I² = 0%, p = 0.89 for heterogeneity based on a random-effects analysis model).

Conclusion

The findings suggest that SHS exposure is associated with the risk of COPD, especially for individuals with a long time exposed.

Trial Registry

Prospero CRD42022329421.

Measurement of airborne nicotine, as a marker of secondhand smoke exposure, in homes with residents who smoke in 9 European countries

OBJECTIVE

Smoke-free policies are effective in preventing secondhand smoke (SHS) exposure, but their adoption at home remains largely voluntary. This study aimed to quantify SHS exposure in homes with residents who smoke in Europe according to households' characteristics, tobacco consumption habits, and national contextual factors.

METHODS

Cross-sectional study (March 2017-September 2018) based on measurements of air nicotine inside 162 homes with residents who smoke from nine European countries. We installed passive samplers for seven consecutive days to monitor nicotine concentrations. Through self-administered questionnaires, we collected sociodemographic information and the number of individuals who smoke, smoking rules, frequency, location, and quantity of tobacco use in households. Country-level factors included the overall score in the Tobacco Control Scale 2016, the smoking prevalence, and self-reported SHS exposure prevalence. Nicotine concentrations were analyzed as continuous and dichotomous variables, categorized based on the limit of quantification of 0.02 μg/m³.

RESULTS

Overall, median nicotine concentration was 0.85 μg/m³ (interquartile range (IQR):0.15-4.42), and there was nicotine presence in 93% of homes. Participants reported that smoking was not permitted in approximately 20% of households, 40% had two or more residents who smoked, and in 79% residents had smoked inside during the week of sampling. We found higher nicotine concentrations in homes: with smell of tobacco smoke inside (1.45 μg/m³ IQR: 0.32-6.34), where smoking was allowed (1.60 μg/m³ IQR: 0.68-7.63), with two or more residents who smoked (2.42 μg/m³ IQR: 0.58-11.0), with more than 40 cigarettes smoked (2.92 μg/m³ IQR: 0.97-10.61), and where two or more residents smoked inside (4.02 μg/m³ IQR: 1.58-11.74). Household nicotine concentrations were significantly higher in countries with higher national smoking prevalence and self-reported SHS exposure prevalence (p < 0.05).

CONCLUSIONS

SHS concentrations in homes with individuals who smoke were approximately twenty times higher in homes that allowed smoking compared to those reporting smoke-free household rules. Evidence-based interventions promoting smoke-free homes should be implemented in combination with strengthening other MPOWER measures.

Trends in Hospital Admissions for Chronic Obstructive Pulmonary Diseases After Comprehensive Tobacco Control Policies in Beijing, China

INTRODUCTION

Only a few studies have examined the effectiveness of tobacco control policies on respiratory conditions, and the results were less consistent. The 2015 Beijing tobacco control policy package incorporating all six components of MPOWER has been implemented since Jun 2015. The present study aimed to evaluate the impact of a comprehensive tobacco control policy package on hospital admissions for chronic obstructive pulmonary disease (COPD) in Beijing, China.

AIMS AND METHODS

An interrupted time-series study was conducted based on the hospital admission information for about 18 million residents, who were covered by the Beijing Medical Claim Data for Employees from January 2013 to June 2017. The average percentage change of COPD hospital admission rates and reductions in hospital admission numbers were estimated by segmented Poisson regression models.

RESULTS

There were 54 040 COPD hospital admissions with a crude rate of 67.2 per 100 000 residents during the observational period. After the implementation of the policy package, the hospital admission rates of COPD were reduced by -14.7% (95%CI: -17.8%, -11.5%) immediately. The secular trend was slowed down by -3.0% (95% CI: -5.6%, -0.4%) annually. A total of 5 581 reductions in COPD hospital admissions were estimated during the 25 months post-law period, accounting for 17.5% (95% CI: 12.5%, 22.5%) of overall COPD hospital admissions. More reductions were shown in males and those aged over 65 years old.

CONCLUSIONS

The results indicated significant protections against hospitalization of COPD after the 2015 Beijing comprehensive tobacco control policy package. The results provide support for public health benefits for respiratory conditions from WHO-recommended tobacco control measures.

IMPLICATIONS

Only a few studies have examined the effectiveness of tobacco control policies on respiratory conditions, and the results were less consistent. Based on medical records for about 18 million residents, this study showed an association between comprehensive tobacco control policies and significant reductions of hospital admissions for chronic obstructive pulmonary disease. The results provide support for public health benefits for respiratory conditions from WHO-recommended tobacco control measures.

Community Interventions for Childhood Asthma ED Visits and Hospitalizations: A Systematic Review

A systematic review of interventions in community environments found significant reductions in childhood asthma exacerbations leading to emergency department visits and hospitalizations.

BACKGROUND AND OBJECTIVES

Structural and social determinants of childhood asthma inequities manifest within geographic communities that are often segregated. Childhood asthma disproportionately affects Black, Hispanic, and low-income populations. Community interventions have the potential to improve inequities in emergency healthcare. This systematic review was conducted to assess the effectiveness of childhood asthma community interventions and provide a conceptual model to inform implementation of future community interventions.

METHODS

Publications from PubMed, ScienceDirect, CINAHL, Cochrane Library, Web of Science, and hand searched references were examined from 2010 to 2021. Community intervention studies among children with asthma were included. Main outcomes were emergency department visits and hospitalizations. Community interventions exclusively focusing on schools or hospitals were excluded. Two reviewers independently assessed eligibility for final inclusion. Emergency healthcare findings were extracted in addition to co-benefits (eg, fewer missed school days and caregiver workdays).

RESULTS

Out of 1856 records, 26 publications met the inclusion criteria. Community interventions were categorized by care coordination (n = 8), policy and environmental changes (eg, smoke-free legislature, traffic reduction models, and green housing) (n = 8), home-based (n = 6), and community-based health services (n = 4). Selected studies indicated that community interventions significantly reduced childhood asthma emergency department visits and hospitalizations through increased caregiver self-efficacy, home environmental trigger reduction, and increased access to healthcare. Because of heterogeneity among studies, we were unable to conduct a meta-analysis.

CONCLUSIONS

Findings show significant associations between community interventions and the reduction of emergency healthcare, suggesting a protective effect for severe cases of childhood asthma.

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

INTRODUCTION

Tobacco smoke exposure (TSE) has considerable adverse respiratory health impact among children. Smoke-free policies covering enclosed public places are known to reduce child TSE and benefit child health. An increasing number of jurisdictions are now expanding smoke-free policies to also cover outdoor areas and/or (semi)private spaces (indoor and/or outdoor). We aim to systematically review the evidence on the impact of these 'novel smoke-free policies' on children's TSE and respiratory health.

METHODS AND ANALYSIS

13 electronic databases will be searched by two independent reviewers for eligible studies. We will consult experts from the field and hand-search references and citations to identify additional published and unpublished studies. Study designs recommended by the Cochrane Effective Practice and Organisation of Care (EPOC) group are eligible, without restrictions on the observational period, publication date or language. Our primary outcomes are: self-reported or parental-reported TSE in places covered by the policy; unplanned hospital attendance for wheezing/asthma and unplanned hospital attendance for respiratory infections. We will assess risk of bias of individual studies following the EPOC or Risk Of Bias In Non-randomised Studies of Interventions tool, as appropriate. We will conduct separate random effects meta-analyses for smoke-free policies covering (1) indoor private places, (2) indoor semiprivate places, (3) outdoor (semi)private places and (4) outdoor public places. We will assess whether the policies were associated with changes in TSE in other locations (eg, displacement). Subgroup analyses will be conducted based on country income classification (ie, high, middle or low income) and by socioeconomic status. Sensitivity analyses will be undertaken via broadening our study design eligibility criteria (ie, including non-EPOC designs) or via excluding studies with a high risk of bias. This review will inform policymakers regarding the implementation of extended smoke-free policies to safeguard children's health.

ETHICS AND DISSEMINATION

Ethical approval is not required. Findings will be disseminated to academics and the general public.

PROSPERO REGISTRATION NUMBER

CRD42020190563.

County Smoke-Free Laws and Cigarette Smoking Among U.S. Adults, 1995-2015

INTRODUCTION

Tobacco use remains the leading cause of preventable death worldwide. Though research on smoke-free policies in the U.S. exists at the state or national level, there is limited evidence on such policies at the county level. This study examined the association between changes in county-level comprehensive smoke-free laws and smoking behavior among U.S. adults.

METHODS

Data were used from the 1995/1996 to the 2014/2015 Tobacco Use Supplement to the Current Population Survey, analyzed in 2019. Changes in county smoke-free law population coverage over time were used as a natural experiment. Quasi-experimental analyses were performed to examine the association between changes in county-level comprehensive smoke-free laws and smoking behavior (smoking status and number of cigarettes smoked).

RESULTS

During the study period, current smoking prevalence decreased from 21.6% to 11.9%. Specifically, the prevalence of every day smoking decreased from 17.1% to 9.1% and some days smoking decreased from 4.4% to 2.9%. The number of cigarettes smoked per day for every day smokers decreased from 18.5 to 13.6, and from 5.9 to 4.1 for those who smoked some days. Comprehensive smoke-free legislation was associated with lower odds of cigarette smoking (AOR=0.76, 95% CI=0.74, 0.79). Adults living in counties with comprehensive smoke-free policies smoked fewer cigarettes per day both for every day smokers (β= -1.55, p<0.0001) and some days smokers (β= -0.79, p<0.0001).

CONCLUSIONS

County smoke-free policies in the U.S. may have contributed significantly to the reduction in smoking prevalence as well as the reduction in the number of cigarettes smoked among continuing cigarette smokers.

Nonallergic Triggers and Comorbidities in Asthma Exacerbations and Disease Severity

Asthma triggers are exogenous or endogenous factors that could worsen asthma acutely to cause an exacerbation, or perpetuate chronic symptoms and airflow limitation. Because it is well known that recent asthma exacerbations and poor symptom control are strong predictors of future disease activity, it is not surprising that the number of (allergic or nonallergic) asthma triggers in the environment correlates with the disease-related quality of life. There is a need to identify and avoid specific triggers as the centerpiece of disease management, especially in those with heightened sensitivity to certain factors.

Cardiovascular disease and high blood pressure trend analyses from 2002 to 2016: after the implementation of a salt reduction strategy

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death around the world; however, many CVD events could be prevented if we focused on modification of the main risk factors. Increased salt consumption is estimated to have caused millions of deaths, mostly related to CVD, particularly stroke, which is the leading cause of death in Portugal. In our study, we aim to assess trends in the proportion of high blood pressure (HBP) in Acute Coronary Syndrome (ACS) patients as well as the trends in stroke and ACS in Portugal, especially after a set of public health initiatives were implemented to reduce salt intake.

METHODS

The monthly proportion of ACS patients presenting with previously diagnosed HBP and the monthly rate of CVD admissions into public hospitals in Portugal were calculated. CVD rates were stratified into ACS rate and stroke rates. Data were stratified by demographics variables. An interrupted time-series model was used to assess changes over time.

RESULTS

Breakpoint analysis revealed an estimated breakpoint around the year 2013 for the proportion of HBP patients, the following year there was a decreasing trend, however it was not significant. Analyses showed the trend before 2013 was increasing and started to decrease after this year. This decreased in proportion of HBP patients can be translated into a reduction of 555 people per year presenting with HBP in the ACS population. We analysed trends for ACS and stroke and tested the significance for a breakpoint in the year 2013. Although none of the remaining trends were significant for ACS crude rates and stroke crude rate, a decreasing trend was observed.

CONCLUSIONS

This research provides an indication about the impact a population-wide approach to CVD risk factors has on CVD trends themselves. Our results suggest that population-wide approaches can have an impact on the prevention and improvement of CVD control, reducing the number of CVD events, and eventually reducing premature death by CVD. As more restrictions on salt intake are being planned in Portugal in the next years, it is highly relevant to assess what is the current panorama and what further reductions we can expect.

Taming Asthma in School-Aged Children: A Comprehensive Review

Asthma is the most common chronic disease of childhood and the leading cause of childhood morbidity as measured by school absences, emergency department visits, and hospitalizations. Multiple factors play a role in the development, treatment and prevention of childhood asthma including racial/ethnic and socioeconomic disparities, both the home and school environments, and medication use. The goals of this review are to summarize these aspects of asthma in school-aged children and to present an updated review of medications as it relates to treatment strategies that will help in the care of these children. We conclude that phenotypic heterogeneity and appropriate environmental assessments and interventions are important considerations in the management of childhood asthma.

Effect of tobacco control policies on perinatal and child health: a systematic review and meta-analysis

BACKGROUND

Tobacco smoking and smoke exposure during pregnancy and childhood cause considerable childhood morbidity and mortality. We did a systematic review and meta-analysis to investigate whether implementation of WHO's recommended tobacco control policies (MPOWER) was of benefit to perinatal and child health.

METHODS

We searched 19 electronic databases, hand-searched references and citations, and consulted experts to identify studies assessing the association between implementation of MPOWER policies and child health. We did not apply any language restrictions, and searched the full time period available for each database, up to June 22, 2017. Our primary outcomes of interest were perinatal mortality, preterm birth, hospital attendance for asthma exacerbations, and hospital attendance for respiratory tract infections. Where possible and appropriate, we combined data from different studies in random-effects meta-analyses. This study is registered with PROSPERO, number CRD42015023448.

FINDINGS

We identified 41 eligible studies (24 from North America, 16 from Europe, and one from China) that assessed combinations of the following MPOWER policies: smoke-free legislation (n=35), tobacco taxation (n=11), and smoking cessation services (n=3). Risk of bias was low in 23 studies, moderate in 16, and high in two. Implementation of smoke-free legislation was associated with reductions in rates of preterm birth (-3·77% [95% CI -6·37 to -1·16]; ten studies, 27 530 183 individuals), rates of hospital attendance for asthma exacerbations (-9·83% [-16·62 to -3·04]; five studies, 684 826 events), and rates of hospital attendance for all respiratory tract infections (-3·45% [-4·64 to -2·25]; two studies, 1 681 020 events) and for lower respiratory tract infections (-18·48% [-32·79 to -4·17]; three studies, 887 414 events). Associations appeared to be stronger when comprehensive smoke-free laws were implemented than when partial smoke-free laws were implemented. Among two studies assessing the association between smoke-free legislation and perinatal mortality, one showed significant reductions in stillbirth and neonatal mortality but did not report the overall effect on perinatal mortality, while the other showed no change in perinatal mortality. Meta-analysis of studies on other MPOWER policies was not possible; all four studies on increasing tobacco taxation and one of two on offering disadvantaged pregnant women help to quit smoking that reported on our primary outcomes had positive findings. Assessment of publication bias was only possible for studies assessing the association between smoke-free legislation and preterm birth, showing some degree of bias.

INTERPRETATION

Smoke-free legislation is associated with substantial benefits to child health. The majority of studies on other MPOWER policies also indicated a positive effect. These findings provide strong support for implementation of such policies comprehensively across the world.

FUNDING

Chief Scientist Office Scotland, Farr Institute, Netherlands Lung Foundation, Erasmus MC.

Smokefree legislation effects on respiratory and sensory disorders: A systematic review and meta-analysis

Aims

The aim of this systematic review and meta-analysis is to synthesize the available evidence in scientific papers of smokefree legislation effects on respiratory diseases and sensory and respiratory symptoms (cough, phlegm, red eyes, runny nose) among all populations.

Materials and methods

Systematic review and meta-analysis were carried out. A search between January 1995 and February 2015 was performed in PubMed, EMBASE, Cochrane Library, Scopus, Web of Science, and Google Scholar databases. Inclusion criteria were: 1) original scientific studies about smokefree legislation, 2) Data before and after legislation were collected, and 3) Impact on respiratory and sensory outcomes were assessed. Paired reviewers independently carried out the screening of titles and abstracts, data extraction from full-text articles, and methodological quality assessment.

Results

A total number of 1606 papers were identified. 50 papers were selected, 26 were related to symptoms (23 concerned workers). Most outcomes presented significant decreases in the percentage of people suffering from them, especially in locations with comprehensive measures and during the immediate post-ban period (within the first six months). Four (50%) of the papers concerning pulmonary function reported some significant improvement in expiratory parameters. Significant decreases were described in 13 of the 17 papers evaluating asthma hospital admissions, and there were fewer significant reductions in chronic obstructive pulmonary disease admissions (range 1–36%) than for asthma (5–31%). Six studies regarding different respiratory diseases showed discrepant results, and four papers about mortality reported significant declines in subgroups. Low bias risk was present in 23 (46%) of the studies.

Conclusions

Smokefree legislation appears to improve respiratory and sensory symptoms at short term in workers (the overall effect being greater in comprehensive smokefree legislation in sensory symptoms) and, to a lesser degree, rates of hospitalization for asthma.

Changes in hospitalizations for chronic respiratory diseases after two successive smoking bans in Spain

Background

Existing evidence on the effects of smoke-free policies on respiratory diseases is scarce and inconclusive. Spain enacted two consecutive smoke-free regulations: a partial ban in 2006 and a comprehensive ban in 2011. We estimated their impact on hospital admissions via emergency departments for chronic obstructive pulmonary disease (COPD) and asthma.

Methods

Data for COPD (ICD-9 490–492, 494–496) came from 2003–2012 hospital admission records from the fourteen largest provinces of Spain and from five provinces for asthma (ICD-9 493). We estimated changes in hospital admission rates within provinces using Poisson additive models adjusted for long-term linear trends and seasonality, day of the week, temperature, influenza, acute respiratory infections, and pollen counts (asthma models). We estimated immediate and gradual effects through segmented-linear models. The coefficients within each province were combined through random-effects multivariate meta-analytic models.

Results

The partial ban was associated with a strong significant pooled immediate decline in COPD-related admission rates (14.7%, 95%CI: 5.0, 23.4), sustained over time with a one-year decrease of 13.6% (95%CI: 2.9, 23.1). The association was consistent across age and sex groups but stronger in less economically developed Spanish provinces. Asthma-related admission rates decreased by 7.4% (95%CI: 0.2, 14.2) immediately after the comprehensive ban was implemented, although the one-year decrease was sustained only among men (9.9%, 95%CI: 3.9, 15.6).

Conclusions

The partial ban was associated with an immediate and sustained strong decline in COPD-related admissions, especially in less economically developed provinces. The comprehensive ban was related to an immediate decrease in asthma, sustained for the medium-term only among men.

Environmental triggers and avoidance in the management of asthma

Identifying asthma triggers forms the basis of environmental secondary prevention. These triggers may be allergenic or nonallergenic. Allergenic triggers include indoor allergens, such as house dust mites (HDMs), molds, pets, cockroaches, and rodents, and outdoor allergens, such as pollens and molds. Clinical observations provide support for the role of HDM exposure as a trigger, although avoidance studies provide conflicting results. Molds and their metabolic products are now considered to be triggers of asthma attacks. Pets, dogs, and especially cats can undoubtedly trigger asthmatic symptoms in sensitized subjects. Avoidance is difficult and rarely adhered to by families. Cockroach allergens contribute to asthma morbidity, and avoidance strategies can lead to clinical benefit. Mouse allergens are mostly found in inner-city dwellings, but their implication in asthma morbidity is debated. In the outdoors, pollens can induce seasonal asthma in sensitized individuals. Avoidance relies on preventing pollens from getting into the house and on minimizing seasonal outdoor exposure. Outdoor molds may lead to severe asthma exacerbations. Nonallergenic triggers include viral infections, active and passive smoking, meteorological changes, occupational exposures, and other triggers that are less commonly involved. Viral infection is the main asthma trigger in children. Active smoking is associated with higher asthma morbidity, and smoking cessation interventions should be personalized. Passive smoking is also a risk factor for asthma exacerbation. The implementation of public smoking bans has led to a reduction in the hospitalization of asthmatic children. Air pollution levels have been linked with asthmatic symptoms, a decrease in lung function, and increased emergency room visits and hospitalizations. Since avoidance is not easy to achieve, clean air policies remain the most effective strategy. Indoor air is also affected by air pollutants, such as cigarette smoke and volatile organic compounds generated by building and cleaning materials. Occupational exposures include work-exacerbated asthma and work-related asthma.

Smoke-free legislation and child health

In this paper, we aim to present an overview of the scientific literature on the link between smoke-free legislation and early-life health outcomes. Exposure to second-hand smoke is responsible for an estimated 166 ,000 child deaths each year worldwide. To protect people from tobacco smoke, the World Health Organization recommends the implementation of comprehensive smoke-free legislation that prohibits smoking in all public indoor spaces, including workplaces, bars and restaurants. The implementation of such legislation has been found to reduce tobacco smoke exposure, encourage people to quit smoking and improve adult health outcomes. There is an increasing body of evidence that shows that children also experience health benefits after implementation of smoke-free legislation. In addition to protecting children from tobacco smoke in public, the link between smoke-free legislation and improved child health is likely to be mediated via a decline in smoking during pregnancy and reduced exposure in the home environment. Recent studies have found that the implementation of smoke-free legislation is associated with a substantial decrease in the number of perinatal deaths, preterm births and hospital attendance for respiratory tract infections and asthma in children, although such benefits are not found in each study. With over 80% of the world’s population currently unprotected by comprehensive smoke-free laws, protecting (unborn) children from the adverse impact of tobacco smoking and SHS exposure holds great potential to benefit public health and should therefore be a key priority for policymakers and health workers alike.

Legislative smoking bans for reducing harms from secondhand smoke exposure, smoking prevalence and tobacco consumption

BACKGROUND

Smoking bans have been implemented in a variety of settings, as well as being part of policy in many jurisdictions to protect the public and employees from the harmful effects of secondhand smoke (SHS). They also offer the potential to influence social norms and the smoking behaviour of those populations they affect. Since the first version of this review in 2010, more countries have introduced national smoking legislation banning indoor smoking.

OBJECTIVES

To assess the effects of legislative smoking bans on (1) morbidity and mortality from exposure to secondhand smoke, and (2) smoking prevalence and tobacco consumption.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register, MEDLINE, EMBASE, PsycINFO, CINAHL and reference lists of included studies. We also checked websites of various organisations. Date of most recent search; February 2015.

SELECTION CRITERIA

We considered studies that reported legislative smoking bans affecting populations. The minimum standard was having an indoor smoking ban explicitly in the study and a minimum of six months follow-up for measures of smoking behaviour. Our search included a broad range of research designs including: randomized controlled trials, quasi-experimental studies (i.e. non-randomized controlled studies), controlled before-and-after studies, interrupted time series as defined by the Cochrane Effective Practice and Organisation of Care Group, and uncontrolled pre- and post-ban data.

DATA COLLECTION AND ANALYSIS

One author extracted characteristics and content of the interventions, participants, outcomes and methods of the included studies and a second author checked the details. We extracted health and smoking behaviour outcomes. We did not attempt a meta-analysis due to the heterogeneity in design and content of the studies included. We evaluated the studies using qualitative narrative synthesis.

MAIN RESULTS

There are 77 studies included in this updated review. We retained 12 studies from the original review and identified 65 new studies. Evidence from 21 countries is provided in this update, an increase of eight countries from the original review. The nature of the intervention precludes randomized controlled trials. Thirty-six studies used an interrupted time series study design, 23 studies use a controlled before-and-after design and 18 studies are before-and-after studies with no control group; six of these studies use a cohort design. Seventy-two studies reported health outcomes, including cardiovascular (44), respiratory (21), and perinatal outcomes (7). Eleven studies reported national mortality rates for smoking-related diseases. A number of the studies report multiple health outcomes. There is consistent evidence of a positive impact of national smoking bans on improving cardiovascular health outcomes, and reducing mortality for associated smoking-related illnesses. Effects on respiratory and perinatal health were less consistent. We found 24 studies evaluating the impact of national smoke-free legislation on smoking behaviour. Evidence of an impact of legislative bans on smoking prevalence and tobacco consumption is inconsistent, with some studies not detecting additional long-term change in existing trends in prevalence.

AUTHORS' CONCLUSIONS

Since the first version of this review was published, the current evidence provides more robust support for the previous conclusions that the introduction of a legislative smoking ban does lead to improved health outcomes through reduction in SHS for countries and their populations. The clearest evidence is observed in reduced admissions for acute coronary syndrome. There is evidence of reduced mortality from smoking-related illnesses at a national level. There is inconsistent evidence of an impact on respiratory and perinatal health outcomes, and on smoking prevalence and tobacco consumption.