A review of the evidence on smoking bans and incidence of heart disease

Evaluation and Mechanistic Investigation of Human Milk Oligosaccharide against SARS-CoV-2

Four human milk oligosaccharides (HMOs), 3'-sialyllactose (3'-SL), 6'-sialyllactose (6'-SL), 2'-fucosyllactose (2'-FL), and 3-fucosyllactose (3-FL), were assessed for their possible antiviral activity against the SARS-CoV-2 spike receptor binding domain (RBD) in vitro. Among them, only 2'-FL/3-FL exhibited obvious antibinding activity against direct binding and trans-binding in competitive immunocytochemistry and enzyme-linked immunosorbent assays. The antiviral effects of 2'-FL/3-FL were further confirmed by pseudoviral assays with three SARS-Cov-2 mutants, with a stronger inhibition effect of 2'-FL than 3-FL. Then, 2'-FL/3-FL were studied with molecular docking and microscale thermophoresis analysis, showing that the binding sites of 2'-FL on RBD were involved in receptor binding, in addition to a tighter bond between them, thus enabling 2'-FL to be more effective than 3-FL. Moreover, the immunomodulation effect of 2'-FL was preliminary evaluated and confirmed in a human alveolus chip. These results would open up possible applications of 2'-FL for the prevention of SARS-CoV-2 infections by competitive binding inhibition.

A Scoping Review of Foci, Trends, and Gaps in Reviews of Tobacco Control Research

INTRODUCTION

The burden of disease associated with tobacco use has prompted a substantial increase in tobacco-related research, but the breadth of this literature has not been comprehensively examined. This review examines the nature of the research addressing the action areas in World Health Organization's Framework Convention on Tobacco Control (FCTC), the populations targeted and how equity-related concepts are integrated.

METHOD

A scoping review of published reviews addressing tobacco control within the primary prevention domain. We searched PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, Educational Resources Information Centre, and PsycInfo from 2004 to 2018.

RESULTS

The scoping review of reviews offered a "birds-eye-view" of the tobacco control literature. Within the 681 reviews meeting inclusion criteria, there was a strong focus on smoking cessation targeting individuals; less attention has been given to product regulation, packaging, and labeling or sales to minors. Equity-related concepts were addressed in 167/681 (24.5%); few were focused on addressing inequity through structural and systemic root causes.

CONCLUSION

This analysis of foci, trends, and gaps in the research pursuant to the FCTC illustrated the particular action areas and populations most frequently addressed in tobacco control research. Further research is needed to address: (1) underlying social influences, (2) particular action areas and with specific populations, and (3) sustained tobacco use through the influence of novel marketing and product innovations by tobacco industry.

IMPLICATIONS

This scoping review of the breadth of tobacco control research reviews enables a better understanding of which action areas and target populations have been addressed in the research. Our findings alongside recommendations from other reviews suggest prioritizing further research to support policymaking and considering the role of the tobacco industry in circumventing tobacco control efforts. The large amount of research targeting individual cessation would suggest there is a need to move beyond a focus on individual choice and decontextualized behaviors. Also, given the majority of reviews that simply recognize or describe disparity, further research that integrates equity and targets various forms of social exclusion and discrimination is needed and may benefit from working in collaboration with communities where programs can be tailored to need and context.

The limits of single-group interrupted time series analysis in assessing the impact of smoke-free laws on short-term mortality

BACKGROUND

Decreases in circulatory/respiratory morbimortality after the January-2006 Spanish partial smoke-free law have been found using designs without control groups, such as single-group interrupted time series (ITS), which are prone to biases. The aim was to reassess the law's impact on mortality using ITS designs with robustness checks.

METHODS

A comprehensive cohort of people aged ≥25 in each calendar-year of 2002-2007, living in 13 of 18 Spanish regions, was followed up between 01/2002 and 12/2007. The law included a smoking ban in indoor public and workplaces, allowing exceptions in catering, hospitality and leisure venues, and other interventions. Post-law changes in monthly coronary/respiratory mortality were estimated using segmented regression, adjusting for relevant covariates, including seasonality, extreme temperatures, influenza incidence and air pollution. The validity of results was assessed using control outcomes, hypothetical law dates, and non-equivalent control groups, analysing their results as difference-in-differences (DID) designs.

RESULTS

Significant immediate post-law decreases in coronary, respiratory and non-tobacco-related mortality were observed among people aged ≥70. A significant immediate post-law decrease in respiratory mortality (-12.7%) was also observed among people age 25-69, although this was neutralized by a subsequent upward trend before 1.5 years. More favourable post-law changes in coronary/respiratory mortality among the target (people aged 25-69) than control groups (people aged ≥70 or women aged ≥80) were not identified in DID designs. Establishing hypothetical law dates, immediate decreases began in February/March 2005 with maxima between April and July 2005.

CONCLUSIONS

After robustness checks, the results do not support a clear positive impact of the 2006 Spanish smoke-free law on short-term coronary/respiratory mortality. The favourable immediate changes observed pre- and post-law could derive mainly from the harvesting effect of the January-2005 cold wave. This highlights the risks of assessing the impact of health interventions using both morbimortality outcomes and designs without a control group and adequate robustness checks.

Updating the evidence relating smoking bans to incidence of heart disease

In our latest update of the evidence on smoking bans and heart disease we summarize 59 studies. We take account of the underlying trends in incidence rates as far as possible by using control data in eight studies, and by adjustment based on observed trends in cases pre- and post-ban in 40 studies, being unable to make an adjustment in the remaining 11 studies. Overall, based on 62 independent estimates from the 59 studies, we estimate that bans reduce incidence by 5.0% (95% CI 3.2-6.8%), though this estimate reduces to 2.9% (0.01-5.6%) when we exclude regional estimates where national estimates are available, and studies where trend adjustment is not possible. For 25 of the studies, quadratic rather than linear adjustment is possible, but this hardly affects the overall estimates. Ban effects are somewhat greater when the pre-ban period studied is relatively short, and in smaller studies. We compare our findings with those in other recent reviews, one of which totally ignored underlying trends and results from control populations. We discuss reasons why we believe there is likely to be a true small effect of smoking bans, and weaknesses in the data which preclude reaching any very confident conclusion.

Environmental tobacco smoke exposure and heart disease: A systematic review

AIM

To review evidence relating passive smoking to heart disease risk in never smokers.

METHODS

Epidemiological studies were identified providing estimates of relative risk (RR) of ischaemic heart disease and 95%CI for never smokers for various indices of exposure to environmental tobacco smoke (ETS). “Never smokers” could include those with a minimal smoking experience. The database set up included the RRs and other study details. Unadjusted and confounder-adjusted RRs were entered, derived where necessary using standard methods. The fixed-effect and random-effects meta-analyses conducted for each exposure index included tests for heterogeneity and publication bias. For the main index (ever smoking by the spouse or nearest equivalent, and preferring adjusted to unadjusted data), analyses investigated variation in the RR by sex, continent, period of publication, number of cases, study design, extent of confounder adjustment, availability of dose-response results and biomarker data, use of proxy respondents, definitions of exposure and of never smoker, and aspects of disease definition. Sensitivity analyses were also run, preferring current to ever smoking, or unadjusted to adjusted estimates, or excluding certain studies.

RESULTS

Fifty-eight studies were identified, 20 in North America, 19 in Europe, 11 in Asia, seven in other countries, and one in 52 countries. Twenty-six were prospective, 22 case-control and 10 cross-sectional. Thirteen included 100 cases or fewer, and 11 more than 1000. For the main index, 75 heterogeneous (P < 0.001) RR estimates gave a combined random-effects RR of 1.18 (95%CI: 1.12-1.24), which was little affected by preferring unadjusted to adjusted RRs, or RRs for current ETS exposure to those for ever exposure. Estimates for each level of each factor considered consistently exceeded 1.00. However, univariate analyses revealed significant (P < 0.001) variation for some factors. Thus RRs were lower for males, and in North American, larger and prospective studies, and also where the RR was for spousal smoking, fatal cases, or specifically for IHD. For case-control studies RRs were lower if hospital/diseased controls were used. RRs were higher when diagnosis was based on medical data rather than death certificates or self-report, and where the never smoker definition allowed subjects to smoke products other than cigarettes or have a limited smoking history. The association with spousal smoking specifically (1.06, 1.01-1.12, n = 34) was less clear in analyses restricted to married subjects (1.03, 0.99-1.07, n = 23). In stepwise regression analyses only those associations with source of diagnosis, study size, and whether the spouse was the index, were independently predictive (at P < 0.05) of heart disease risk. A significant association was also evident with household exposure (1.19, 1.13-1.25, n = 37). For those 23 studies providing dose-response results for spouse or household exposure, 11 showed a significant (P < 0.05) positive trend including the unexposed group, and two excluding it. Based on fewer studies, a positive, but non-significant (P > 0.05) association was found for workplace exposure (RR = 1.08, 95%CI: 0.99-1.19), childhood exposure (1.12, 0.95-1.31), and biomarker based exposure indices (1.15, 0.94-1.40). However, there was a significant association with total exposure (1.23, 1.12-1.35). Some significant positive dose-response trends were also seen for these exposure indices, particularly total exposure, with no significant negative trends seen. The evidence suffers from various weaknesses and biases. Publication bias may explain the large RR (1.66, 1.30-2.11) for the main exposure index for smaller studies (1-99 cases), while recall bias may explain the higher RRs seen in case-control and cross-sectional than in prospective studies. Some bias may also derive from including occasional smokers among the “never smokers”, and from misreporting smoking status. Errors in determining ETS exposure, and failing to update exposure data in long term prospective studies, also contribute to the uncertainty. The tendency for RRs to increase as more factors are adjusted for, argues against the association being due to uncontrolled confounding.

CONCLUSION

The increased risk and dose-response for various exposure indices suggests ETS slightly increases heart disease risk. However heterogeneity, study limitations and possible biases preclude definitive conclusions.

Impact of institutional smoking bans on reducing harms and secondhand smoke exposure

BACKGROUND

Smoking bans or restrictions can assist in eliminating nonsmokers' exposure to the dangers of secondhand smoke and can reduce tobacco consumption amongst smokers themselves. Evidence exists identifying the impact of tobacco control regulations and interventions implemented in general workplaces and at an individual level. However, it is important that we also review the evidence for smoking bans at a meso- or organisational level, to identify their impact on reducing the burden of exposure to tobacco smoke. Our review assesses evidence for meso- or organisational-level tobacco control bans or policies in a number of specialist settings, including public healthcare facilities, higher education and correctional facilities.

OBJECTIVES

To assess the extent to which institutional smoking bans may reduce passive smoke exposure and active smoking, and affect other health-related outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE, EMBASE, and the reference lists of identified studies. We contacted authors to identify completed or ongoing studies eligible for inclusion in this review. We also checked websites of state agencies and organisations, such as trial registries. Date of latest searches was 22nd June 2015.

SELECTION CRITERIA

We considered studies that reported the effects of tobacco bans or policies, whether complete or partial, on reducing secondhand smoke exposure, tobacco consumption, smoking prevalence and other health outcomes, in public healthcare, higher educational and correctional facilities, from 2005 onwards.The minimum standard for inclusion was having a settings-level policy or ban implemented in the study, and a minimum of six months follow-up for measures of smoking behaviour. We included quasi-experimental studies (i.e. controlled before-and-after studies), interrupted time series as defined by the Cochrane Effective Practice and Organization of Care Group, and uncontrolled pre- and post-ban data.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently assessed studies for inclusion in the review. Due to variation in the measurement of outcomes we did not conduct a meta-analysis for all of the studies included in this review, but carried out a Mantel-Haenszel fixed-effect meta-analysis, pooling 11 of the included studies. We evaluated all studies using a qualitative narrative synthesis.

MAIN RESULTS

We included 17 observational studies in this review. We found no randomized controlled trials. Twelve studies are based in hospitals, three in prisons and two in universities. Three studies used a controlled before-and-after design, with another site used for comparison. The remaining 14 studies used an uncontrolled before-and-after study design. Five studies reported evidence from two participant groups, including staff and either patients or prisoners (depending on specialist setting), with the 12 remaining studies investigating only one participant group.The four studies (two in prisons, two in hospitals) providing health outcomes data reported an effect of reduced secondhand smoke exposure and reduced mortality associated with smoking-related illnesses. No studies included in the review measured cotinine levels to validate secondhand smoke exposure. Eleven studies reporting active smoking rates with 12,485 participants available for pooling, but with substantial evidence of statistical heterogeneity (I² = 72%). Heterogeneity was lower in subgroups defined by setting, and provided evidence for an effect of tobacco bans on reducing active smoking rates. An analysis exploring heterogeneity within hospital settings showed evidence of an effect on reducing active smoking rates in both staff (risk ratio (RR) 0.71, 95% confidence interval ( CI) 0.64 to 0.78) and patients (RR 0.86, 95% CI 0.76 to 0.98), but heterogeneity remained in the staff subgroup (I² = 76%). In prisons, despite evidence of reduced mortality associated with smoking-related illnesses in two studies, there was no evidence of effect on active smoking rates (1 study, RR 0.99, 95% CI 0.84 to 1.16).We judged the quality of the evidence to be low, using the GRADE approach, as the included studies are all observational.

AUTHORS' CONCLUSIONS

We found evidence of an effect of settings-based smoking policies on reducing smoking rates in hospitals and universities. In prisons, reduced mortality rates and reduced exposure to secondhand smoke were reported. However, we rated the evidence base as low quality. We therefore need more robust studies assessing the evidence for smoking bans and policies in these important specialist settings.

Benefits of smoking bans on preterm and early-term births: a natural experimental design in Switzerland

BACKGROUND

Birth outcomes are relevant for future children's heath. Capitalising on a natural experimental design in Switzerland, we evaluated how regional smoking bans introduced at different time points affected birth outcomes, including preterm and early-term births.

METHODOLOGY

We used birth registry data of all singleton neonates born in Switzerland (2007-2012). We developed canton-specific interrupted time-series followed by random meta-analysis to evaluate the benefits of smoking bans on preterm (<37 gestational weeks) and early-term (37-38 gestational weeks) births. Heterogeneity across type of ban and contextual characteristics was explored through metaregression. A time-to-event approach was used for evaluating duration of pregnancy under the smoking bans and effects, taking into account individual maternal factors.

RESULTS

We observed a decrease in the risk of preterm birth of 3.6% (95% CI, -9.3% to 2.5%), and early-term birth of 5.0% (95% CI -7.5% to -2.5%). Results showed a clear dose-response relationship. Greater risk reductions were obtained for preterm births in areas with more comprehensive bans (-6.8%; 95% CI -12.1% to 0.1%), and for pregnancies with the longest gestational time under smoking bans (HR, 0.991; 95% CI 0.984 to 0.997 per 10% increase in duration). Benefits were unequal across outcomes and characteristics of cantons and mothers.

CONCLUSION

Smoking bans resulted in improved birth outcomes in Switzerland with cantons that adopted more comprehensive smoking bans achieving greater benefits. Early-term births constitute a previously ignored though important group.

Propensity score matching for selection of local areas as controls for evaluation of effects of alcohol policies in case series and quasi case-control designs

OBJECTIVES

Area-level public health interventions can be difficult to evaluate using natural experiments. We describe the use of propensity score matching (PSM) to select control local authority areas (LAU) to evaluate the public health impact of alcohol policies for (1) prospective evaluation of alcohol policies using area-level data, and (2) a novel two-stage quasi case-control design.

STUDY DESIGN

Ecological.

METHODS

Alcohol-related indicator data (Local Alcohol Profiles for England, PHE Health Profiles and ONS data) were linked at LAU level. Six LAUs (Blackpool, Bradford, Bristol, Ipswich, Islington, and Newcastle-upon-Tyne) as sample intervention or case areas were matched to two control LAUs each using PSM. For the quasi case-control study a second stage was added aimed at obtaining maximum contrast in outcomes based on propensity scores. Matching was evaluated based on average standardized absolute mean differences (ASAM) and variable-specific P-values after matching.

RESULTS

The six LAUs were matched to suitable control areas (with ASAM < 0.20, P-values >0.05 indicating good matching) for a prospective evaluation study that sought areas that were similar at baseline in order to assess whether a change in intervention exposure led to a change in the outcome (alcohol related harm). PSM also generated appropriate matches for a quasi case-control study--whereby the contrast in health outcomes between cases and control areas needed to be optimized in order to assess retrospectively whether differences in intervention exposure were associated with the outcome.

CONCLUSIONS

The use of PSM for area-level alcohol policy evaluation, but also for other public health interventions, will improve the value of these evaluations by objective and quantitative selection of the most appropriate control areas.