Methodological biases in estimating the relationship between alcohol consumption and breast cancer: the role of drinker misclassification errors in meta-analytic results

Umbrella review and Delphi study on modifiable factors for dementia risk reduction

A 2013 systematic review and Delphi consensus study identified 12 modifiable risk and protective factors for dementia, which were subsequently merged into the "LIfestyle for BRAin health" (LIBRA) score. We systematically evaluated whether LIBRA requires revision based on new evidence. To identify modifiable risk and protective factors suitable for dementia risk reduction, we combined an umbrella review of systematic reviews and meta-analyses with a two-round Delphi consensus study. The review of 608 unique primary studies and opinions of 18 experts prioritized six modifiable factors: hearing impairment, social contact, sleep, life course inequalities, atrial fibrillation, and psychological stress. Based on expert ranking, hearing impairment, social contact, and sleep were considered the most suitable candidates for inclusion in updated dementia risk scores. As such, the current study shows that dementia risk scores need systematic updates based on emerging evidence. Future studies will validate the updated LIBRA score in different cohorts. HIGHLIGHTS: An umbrella review was combined with opinions of 18 dementia experts. Various candidate targets for dementia risk reduction were identified. Experts prioritized hearing impairment, social contact, and sleep. Re-assessment of dementia risk scores is encouraged. Future work should evaluate the predictive validity of updated risk scores.

[Potential impact of increased alcohol taxes on the alcohol-attributable burden of disease in Germany: a modelling study]

Hintergrund

Deutschland gehörte im Jahr 2019 zu den Ländern mit dem weltweit höchsten Pro-Kopf-Alkoholkonsum, welcher wesentlich zur Krankheitslast beiträgt.

Fragestellung

In dieser Modellierungsstudie schätzen wir, wie viele alkoholbedingte inzidente Krankheits- sowie Todesfälle in Deutschland im Jahr 2019 hätten vermieden werden können, wenn die derzeitigen Verbrauchssteuern auf Alkohol um 20 %, 50 % und 100 % erhöht worden wären.

Methodik

Ausgangspunkt für die Modellierung sind die spezifischen Verbrauchssteuern auf alkoholische Getränke in Deutschland. Drei Szenarien wurden unter der Annahme, dass die resultierende Steuererhöhung vollständig in den Verkaufspreis übertragen wird, und unter Verwendung von getränkespezifischen Preiselastizitäten modelliert. Mittels des sich daraus ergebenden Rückgangs im jährlichen Pro-Kopf-Konsum und der krankheitsspezifischen Risikofunktionen wurde die vermeidbare alkoholbedingte Inzidenz bzw. Mortalität geschätzt. Berücksichtigt wurden alkoholbedingte Erkrankungen des Herz-Kreislauf- und Verdauungssystems, Alkoholabhängigkeit, Epilepsie, Infektionskrankheiten sowie Verletzungen und Unfälle.

Ergebnisse

Insgesamt hätten durch eine Verdoppelung der spezifischen Verbrauchssteuern auf Alkohol im Jahr 2019 bis zu 200.400 alkoholbedingte Erkrankungs- und Verletzungsfälle sowie 2800 Todesfälle vermieden werden können. Dies entspricht knapp 7 % der berücksichtigten alkoholbedingten Krankheits- bzw. Todesfälle in Deutschland.

Diskussion

Alkoholbedingte Erkrankungen und Verletzungen sind vermeidbar und eine Erhöhung der spezifischen Verbrauchssteuern auf alkoholische Getränke in Deutschland könnte die alkoholbedingte Krankheitslast substanziell reduzieren.

Zusatzmaterial online

Zusätzliche Informationen sind in der Online-Version dieses Artikels (10.1007/s00103-022-03528-9) enthalten.

Alcohol Consumption: Discussing Potential Risks for Informed Decisions in Breast Cancer Survivors

BACKGROUND

Alcohol consumption is a known risk factor for breast cancer. Because breast cancer survivors are already at risk for recurrence, it is important to understand whether these survivors could benefit from survivor-specific recommendations for alcohol consumption.

OBJECTIVES

The purpose of this article was to review primary research specific to alcohol and breast cancer survivors to see whether those who consume alcohol experience more adverse effects.

METHODS

This literature review examined nine cohort studies specific to breast cancer survivors, alcohol consumption, and risks for breast cancer recurrence, breast cancer-specific mortality, and second primary breast cancers.

FINDINGS

Current guideline recommendations of a safe limit of one drink per day or less may not protect breast cancer survivors from cancer- related adverse events. The authors recommend that breast cancer survivors be educated about the associated risks of alcohol consumption so that they can make informed decisions about usage.

A systematic comparison of the global comparative risk assessments for alcohol

AIMS

To compare systematically the alcohol-attributable mortality and burden of disease estimates for 2016 from a recent study by Shield and colleagues and the Global Burden of Disease study 2017 (GBD).

METHOD

This study compared estimates of alcohol-attributable mortality and disability adjusted life years (DALYs) lost for 2016 with regards to absolute and relative differences, by region and by cause of disease or injury. Relative differences between the two studies are reported herein as percentage (%) differences. A difference of 10% or more was considered meaningful.

RESULTS

The studies estimated similar global levels of overall alcohol-attributable mortality for 2016 (Shield and colleagues estimated 5.1% more alcohol-attributable mortality than the GBD study) but not alcohol-attributable DALYs lost (18.3% difference). There were marked differences by region and cause of disease or injury. Compared with the results from Shield and colleagues, the GBD study estimated a lower alcohol-attributable burden in Eastern Europe by 252 770 alcohol-attributable deaths (45.2% difference) and 6.1 million alcohol-attributable DALYs lost (32.9% difference) and in Western sub-Saharan Africa by 124 200 alcohol-attributable deaths (55.7% difference) and 7.0 million alcohol-attributable DALYs lost (63.4% difference), and estimated a higher alcohol-attributable burden in East Asia by 227 100 alcohol-attributable deaths (48.0% difference) and 2.2 million DALYs lost (11.0% difference). With regard to the cause of disease or injury, Shield and colleagues attributed an overall detrimental effect to alcohol on ischaemic heart disease mortality, whereas the GBD study attributed a net beneficial effect. The GBD study, as compared with Shield and colleagues' study, estimated a lower alcohol-attributable mortality because of liver cirrhosis and injuries by 262 500 (44.6% difference) and 398 800 (46.2% difference), respectively.

CONCLUSIONS

Differences in estimates of the alcohol-attributable burden of disease in two recent studies indicate the need to improve the accuracy of underlying data and risk relations to obtain more consistent estimates and to formulate, advocate for, and implement alcohol policies more effectively.

Measurement error in meta-analysis (MEMA)-A Bayesian framework for continuous outcome data subject to non-differential measurement error

Ideally, a meta-analysis will summarize data from several unbiased studies. Here we look into the less than ideal situation in which contributing studies may be compromised by non-differential measurement error in the exposure variable. Specifically, we consider a meta-analysis for the association between a continuous outcome variable and one or more continuous exposure variables, where the associations may be quantified as regression coefficients of a linear regression model. A flexible Bayesian framework is developed which allows one to obtain appropriate point and interval estimates with varying degrees of prior knowledge about the magnitude of the measurement error. We also demonstrate how, if individual-participant data (IPD) are available, the Bayesian meta-analysis model can adjust for multiple participant-level covariates, these being measured with or without measurement error.

Alcohol, health and cardiovascular disease

Recent epidemiological studies have shown that alcohol consumption can increase the risk of arterial hypertension, atrial fibrillation and gastrointestinal and breast cancer. Various sectors are therefore promoting abstinence from alcohol. However, light alcohol consumption has once again been shown to reduce the risk of myocardial infarction and diabetes but with an unclear effect on cerebrovascular disease. The decision to consume alcohol should therefore be an individual one based on personal factors. A level of consumption <100g/week for men (less for women) appears not to increase all-cause mortality, while high consumption or binge drinking significantly increases mortality risk. All measures to prevent this type of consumption, especially among the younger population, should therefore be applied. There are data indicating an advantage of wine over other beverages, but they are not conclusive.

A cross-sectional analysis of binge drinking levels in US myocardial infarction survivors

BACKGROUND

Although binge drinking is associated with higher myocardial infarction (MI) incidence, little is known about binge drinking patterns in US MI survivors, at elevated risk for recurrent MIs.

OBJECTIVES

To determine the prevalence of and what factors are associated with binge drinking in US MI survivors.

METHODS

We compared the prevalence of binge drinking between MI survivors and those without a MI history in 2016-2018 Behavioral Risk Factor Surveillance System data. Logistic regression was used to examine which sociodemographic factors are associated with binge drinking in these groups.

RESULTS

8.7% of MI survivors (1.1 million people nationwide) were binge drinkers. Among MI survivors; being young, male, Hispanic, having higher income, and having lower educational attainment were associated with increased binge drinking.

CONCLUSIONS

The sizable number of US MI survivors who binge drink suggests interventions to reduce this behavior are warranted, especially among specific sociodemographic groups of this population.

Differentiating Types of Self-Reported Alcohol Abstinence

We contrast three types of abstinence: quit after alcohol associated problems (Q-AP), quit for other reasons (Q-OR), and lifetime abstainer (LTA). We summarized the characteristics of people living with HIV (PLWH), and matched uninfected individuals, by levels of alcohol use and types of abstinence. We then identified factors that differentiate abstinence and determined whether the association with an alcohol biomarker or a genetic polymorphism is improved by differentiating abstinence. Among abstainers, 34% of PLWH and 38% of uninfected were Q-AP; 53% and 53% were Q-OR; and 12% and 10% were LTA. Logistic regression models found smoking, alcohol, cocaine, and hepatitis C increased odds of Q-AP, whereas smoking and marijuana decreased odds of LTA. Differentiating types of abstinence improved association. Q-APs and LTAs can be readily differentiated by an alcohol biomarker and genetic polymorphism. Differentiating type of abstinence may enhance understanding of alcohol health effects.

Alcohol, health and cardiovascular disease

Recent epidemiological studies have shown that alcohol consumption can increase the risk of arterial hypertension, atrial fibrillation and gastrointestinal and breast cancer. Various sectors are therefore promoting abstinence from alcohol. However, light alcohol consumption has once again been shown to reduce the risk of myocardial infarction and diabetes but with an unclear effect on cerebrovascular disease. The decision to consume alcohol should therefore be an individual one based on personal factors. A level of consumption <100 g/week for men (less for women) appears not to increase all-cause mortality, while high consumption or binge drinking significantly increases mortality risk. All measures to prevent this type of consumption, especially among the younger population, should therefore be applied. There are data indicating an advantage of wine over other beverages, but they are not conclusive.

Alcohol consumption and all-cause mortality in older adults in Spain: an analysis accounting for the main methodological issues

BACKGROUND AND AIMS

Observational evidence that light-to-moderate alcohol consumption lowers mortality is questioned because of potential selection biases and residual confounding. We assess the association between alcohol intake and all-cause death in older adults after accounting for those methodological issues.

METHODS

Data came from 3045 individuals representative of the non-institutionalized population aged ≥ 60 years in Spain. Participants were recruited in 2008-10, when they reported current and life-time alcohol intake; drinkers were classified as occasional (< 1.43 g/day), light (≥ 1.43 but < 20 g/day for men and ≥ 1.43 but < 10 g/day for women), moderate (≥ 20 but < 40 g/day for men and ≥ 10 but < 20 g/day for women) or heavy (≥ 40 g/day for men and ≥ 24 g/day for women)/binge. Participants were followed-up to 2017 to assess vital status. In analyses, ex-drinkers were removed from the abstainer group and were classified according to their life-time intake to address the 'abstainer bias'. Moreover, analyses were replicated in individuals without functional limitations, and excluded deaths in the first year of follow-up, to address reverse causation. Also, occasional drinkers were used as reference in some analyses to reduce the 'healthy drinker/survivor' bias. Results were adjusted for many covariates to minimize residual confounding.

RESULTS

Compared with never-drinkers, the hazard ratio (95% confidence interval) of mortality for light drinkers was 1.05 (0.71-1.56) and 1.20 (0.72-2.02) in those without functional limitations. Corresponding values for moderate drinkers were 1.28 (0.81-2.02) and 1.55 (0.87-2.75) and for heavy/binge drinkers 1.85 (1.07-3.23) and 2.15 (1.09-4.22). Results were consistent when occasional drinkers were used as reference. Among drinkers without functional limitations, the hazard ratio (95% confidence interval) of mortality per 10 g/day of alcohol was 1.12 (1.02-1.23).

CONCLUSION

After accounting for potential biases, light-to-moderate drinking among people 60+ years of age appears to have no statistically significant benefit on mortality compared with abstention from alcohol. By contrast, heavy/binge drinking shows a higher death risk compared with abstention from alcohol. Alcohol intake appears to have a positive dose-response with mortality among drinkers.

A Bayesian approach for correcting exposure misclassification in meta-analysis

In observational studies, misclassification of exposure is ubiquitous and can substantially bias the estimated association between an outcome and an exposure. Although misclassification in a single observational study has been well studied, few papers have considered it in a meta-analysis. Meta-analyses of observational studies provide important evidence for health policy decisions, especially when large randomized controlled trials are unethical or unavailable. It is imperative to account properly for misclassification in a meta-analysis to obtain valid point and interval estimates. In this paper, we propose a novel Bayesian approach to filling this methodological gap. We simultaneously synthesize two (or more) meta-analyses, with one on the association between a misclassified exposure and an outcome (main studies), and the other on the association between the misclassified exposure and the true exposure (validation studies). We extend the current scope for using external validation data by relaxing the "transportability" assumption by means of random effects models. Our model accounts for heterogeneity between studies and can be extended to allow different studies to have different exposure measurements. The proposed model is evaluated through simulations and illustrated using real data from a meta-analysis of the effect of cigarette smoking on diabetic peripheral neuropathy.

Alcohol intake and gastric cancer: Meta-analyses of published data versus individual participant data pooled analyses (StoP Project)

BACKGROUND

Individual participant data pooled analyses allow access to non-published data and statistical reanalyses based on more homogeneous criteria than meta-analyses based on systematic reviews. We quantified the impact of publication-related biases and heterogeneity in data analysis and presentation in summary estimates of the association between alcohol drinking and gastric cancer.

METHODS

We compared estimates obtained from conventional meta-analyses, using only data available in published reports from studies that take part in the Stomach Cancer Pooling (StoP) Project, with individual participant data pooled analyses including the same studies.

RESULTS

A total of 22 studies from the StoP Project assessed the relation between alcohol intake and gastric cancer, 19 had specific data for levels of consumption and 18 according to cancer location; published reports addressing these associations were available from 18, 5 and 5 studies, respectively. The summary odds ratios [OR, (95%CI)] estimate obtained with published data for drinkers vs. non-drinkers was 10% higher than the one obtained with individual StoP data [18 vs. 22 studies: 1.21 (1.07-1.36) vs. 1.10 (0.99-1.23)] and more heterogeneous (I²: 63.6% vs 54.4%). In general, published data yielded less precise summary estimates (standard errors up to 2.6 times higher). Funnel plot analysis suggested publication bias.

CONCLUSION

Meta-analyses of the association between alcohol drinking and gastric cancer tended to overestimate the magnitude of the effects, possibly due to publication bias. Additionally, individual participant data pooled analyses yielded more precise estimates for different levels of exposure or cancer subtypes.

The stability of baseline-defined categories of alcohol consumption during the adult life-course: a 28-year prospective cohort study

BACKGROUND AND AIMS

Studies that report the relationship between alcohol consumption and disease risk have predominantly operationalized drinking according to a single baseline measure. The resulting assumption of longitudinal stability may be simplistic and complicate interpretation of risk estimates. This study aims to describe changes to the volume of consumption during the adult life-course according to baseline categories of drinking.

DESIGN

A prospective observational study.

SETTING

United Kingdom.

PARTICIPANTS

A cohort of British civil servants totalling 6838 men and 3372 women aged 34-55 years at baseline, followed for a mean 19.1 (standard deviation = 9.5) years.

MEASUREMENTS

The volume of weekly alcohol consumption was estimated from data concerning the frequency and number of drinks consumed. Baseline categories were defined: non-current drinkers, infrequent drinkers, 0.1-50.0 g/week, 50.1-100.0 g/week, 100.1-150.0 g/week, 150.1-250.0 g/week and >250.0 g/week. For women, the highest category was defined as > 100.0 g/week. Baseline frequency was derived as 'daily or almost daily' and 'not daily or almost daily'. Trajectories were estimated within baseline categories using growth curve models.

FINDINGS

Trajectories differed between men and women, but were relatively stable within light-to-moderate categories of baseline consumption. Drinking was least stable within the highest categories of baseline consumption (men: > 250.0 g/week; women: > 100.0 g/week), declining by 47.0 [95% confidence interval (CI) = 40.7, 53.2] and 16.8 g/week (95% CI = 12.6, 21.0), respectively, per 10-year increase in age. These declines were not a consequence of sudden transitions to complete abstention. Rates of decline appear greatest in older age, with trajectories converging toward moderate volumes.

CONCLUSION

Among UK civil servants, consumption within baseline drinking categories is generally stable during the life-course, except among heavier baseline drinkers, for whom intakes decline with increasing age. This shift does not appear to be driven by transitions to non-drinking. Cohorts of older people may be at particular risk of misclassifying former heavy drinkers as moderate consumers of alcohol.

Relationship of Alcohol Consumption to All-Cause, Cardiovascular, and Cancer-Related Mortality in U.S. Adults

BACKGROUND

Previous studies have revealed inconsistent findings regarding the association of light to moderate alcohol consumption with cardiovascular disease (CVD) and cancer mortality.

OBJECTIVES

The aim of this study was to examine the association between alcohol consumption and risk of mortality from all causes, cancer, and CVD in U.S. adults.

METHODS

Data were obtained by linking 13 waves of the National Health Interview Surveys (1997 to 2009) to the National Death Index records through December 31, 2011. A total of 333,247 participants ≥18 years of age were included. Self-reported alcohol consumption patterns were categorized into 6 groups: lifetime abstainers; lifetime infrequent drinkers; former drinkers; and current light, moderate, or heavy drinkers. Secondary exposure included participants' binge-drinking status. The main outcome was all-cause, cancer, or CVD mortality.

RESULTS

After a median follow-up of 8.2 years (2.7 million person-years), 34,754 participants died of all causes (including 8,947 CVD deaths and 8,427 cancer deaths). Compared with lifetime abstainers, those who were light or moderate alcohol consumers were at a reduced risk of mortality for all causes (light-hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.76 to 0.82; moderate-HR: 0.78; 95% CI: 0.74 to 0.82) and CVD (light-HR: 0.74; 95% CI: 0.69 to 0.80; moderate-HR: 0.71; 95% CI: 0.64 to 0.78), respectively. In contrast, there was a significantly increased risk of mortality for all causes (HR: 1.11; 95% CI: 1.04 to 1.19) and cancer (HR: 1.27; 95% CI: 1.13 to 1.42) in adults with heavy alcohol consumption. Binge drinking ≥1 d/week was also associated with an increased risk of mortality for all causes (HR: 1.13; 95% CI: 1.04 to 1.23) and cancer (HR: 1.22; 95% CI: 1.05 to 1.41).

CONCLUSIONS

Light and moderate alcohol intake might have a protective effect on all-cause and CVD-specific mortality in U.S. adults. Heavy or binge drinking was associated with increased risk of all-cause and cancer-specific mortality.

Life-time risk of mortality due to different levels of alcohol consumption in seven European countries: implications for low-risk drinking guidelines

BACKGROUND AND AIMS

Low-risk alcohol drinking guidelines require a scientific basis that extends beyond individual or group judgements of risk. Life-time mortality risks, judged against established thresholds for acceptable risk, may provide such a basis for guidelines. Therefore, the aim of this study was to estimate alcohol mortality risks for seven European countries based on different average daily alcohol consumption amounts.

METHODS

The maximum acceptable voluntary premature mortality risk was determined to be one in 1000, with sensitivity analyses of one in 100. Life-time mortality risks for different alcohol consumption levels were estimated by combining disease-specific relative risk and mortality data for seven European countries with different drinking patterns (Estonia, Finland, Germany, Hungary, Ireland, Italy and Poland). Alcohol consumption data were obtained from the Global Information System on Alcohol and Health, relative risk data from meta-analyses and mortality information from the World Health Organization.

RESULTS

The variation in the life-time mortality risk at drinking levels relevant for setting guidelines was less than that observed at high drinking levels. In Europe, the percentage of adults consuming above a risk threshold of one in 1000 ranged from 20.6 to 32.9% for women and from 35.4 to 54.0% for men. Life-time risk of premature mortality under current guideline maximums ranged from 2.5 to 44.8 deaths per 1000 women in Finland and Estonia, respectively, and from 2.9 to 35.8 deaths per 1000 men in Finland and Estonia, respectively. If based upon an acceptable risk of one in 1000, guideline maximums for Europe should be 8-10 g/day for women and 15-20 g/day for men.

CONCLUSIONS

If low-risk alcohol guidelines were based on an acceptable risk of one in 1000 premature deaths, then maximums for Europe should be 8-10 g/day for women and 15-20 g/day for men, and some of the current European guidelines would require downward revision.

The relationship between different dimensions of alcohol use and the burden of disease-an update

BACKGROUND AND AIMS

Alcohol use is a major contributor to injuries, mortality and the burden of disease. This review updates knowledge on risk relations between dimensions of alcohol use and health outcomes to be used in global and national Comparative Risk Assessments (CRAs).

METHODS

Systematic review of reviews and meta-analyses on alcohol consumption and health outcomes attributable to alcohol use. For dimensions of exposure: volume of alcohol use, blood alcohol concentration and patterns of drinking, in particular heavy drinking occasions were studied. For liver cirrhosis, quality of alcohol was additionally considered. For all outcomes (mortality and/or morbidity): cause of death and disease/injury categories based on International Classification of Diseases (ICD) codes used in global CRAs; harm to others.

RESULTS

In total, 255 reviews and meta-analyses were identified. Alcohol use was found to be linked causally to many disease and injury categories, with more than 40 ICD-10 three-digit categories being fully attributable to alcohol. Most partially attributable disease categories showed monotonic relationships with volume of alcohol use: the more alcohol consumed, the higher the risk of disease or death. Exceptions were ischaemic diseases and diabetes, with curvilinear relationships, and with beneficial effects of light to moderate drinking in people without heavy irregular drinking occasions. Biological pathways suggest an impact of heavy drinking occasions on additional diseases; however, the lack of medical epidemiological studies measuring this dimension of alcohol use precluded an in-depth analysis. For injuries, except suicide, blood alcohol concentration was the most important dimension of alcohol use. Alcohol use caused marked harm to others, which has not yet been researched sufficiently.

CONCLUSIONS

Research since 2010 confirms the importance of alcohol use as a risk factor for disease and injuries; for some health outcomes, more than one dimension of use needs to be considered. Epidemiological studies should include measurement of heavy drinking occasions in line with biological knowledge.

The Association Between Health Changes and Cessation of Alcohol Consumption

AIMS

To assess whether health changes affect cessation of alcohol consumption and to compare the health status of former drinkers and abstainers.

METHODS

Cohort data from 9001 Korean participants aged 40-69 years old were analyzed. Alcohol consumption was assessed every 2 years for 10 years. Participant age, sex, marital status, education level, employment status, smoking, chronic disease, perceived health and changes in these variables were analyzed to identify factors associated with quitting alcohol drinking. The number of diseases and perceived health of former drinkers and people who at baseline were lifetime abstainers were compared.

RESULTS

Among 4037 drinkers at baseline, 673 (16.7%) were classed as quitters and 3364 (83.3%) were classed as non-quitters. Sex, age and worsened perception of health were significantly associated with cessation of drinking. Women and individuals >60 years were more likely to cease drinking. There was a significant association between disease onset or treatment and alcohol cessation for cancer cases, but not for cardiovascular disease or chronic disease cases. There was no significant difference in number of diseases or perceived health between former drinkers and people who at baseline were lifetime abstainers.

CONCLUSIONS

The effect of disease onset or treatment on alcohol consumption cessation depended on disease type. Former drinkers did not show significantly worse health than people who at baseline were lifetime abstainers. Further studies of alcohol consumption and its effects on health are needed to consider disease occurrence and changes in alcohol consumption.

SHORT SUMMARY

Disease onset or treatment significantly affected alcohol consumption cessation for cancer cases, but not for cardiovascular disease or other chronic disease cases. There was no significant difference in health status between former drinkers and lifetime abstainers.

The relationship between different dimensions of alcohol use and the burden of disease-an update

BACKGROUND AND AIMS

Alcohol use is a major contributor to injuries, mortality and the burden of disease. This review updates knowledge on risk relations between dimensions of alcohol use and health outcomes to be used in global and national Comparative Risk Assessments (CRAs).

METHODS

Systematic review of reviews and meta-analyses on alcohol consumption and health outcomes attributable to alcohol use. For dimensions of exposure: volume of alcohol use, blood alcohol concentration and patterns of drinking, in particular heavy drinking occasions were studied. For liver cirrhosis, quality of alcohol was additionally considered. For all outcomes (mortality and/or morbidity): cause of death and disease/injury categories based on International Classification of Diseases (ICD) codes used in global CRAs; harm to others.

RESULTS

In total, 255 reviews and meta-analyses were identified. Alcohol use was found to be linked causally to many disease and injury categories, with more than 40 ICD-10 three-digit categories being fully attributable to alcohol. Most partially attributable disease categories showed monotonic relationships with volume of alcohol use: the more alcohol consumed, the higher the risk of disease or death. Exceptions were ischaemic diseases and diabetes, with curvilinear relationships, and with beneficial effects of light to moderate drinking in people without heavy irregular drinking occasions. Biological pathways suggest an impact of heavy drinking occasions on additional diseases; however, the lack of medical epidemiological studies measuring this dimension of alcohol use precluded an in-depth analysis. For injuries, except suicide, blood alcohol concentration was the most important dimension of alcohol use. Alcohol use caused marked harm to others, which has not yet been researched sufficiently.

CONCLUSIONS

Research since 2010 confirms the importance of alcohol use as a risk factor for disease and injuries; for some health outcomes, more than one dimension of use needs to be considered. Epidemiological studies should include measurement of heavy drinking occasions in line with biological knowledge.

Alcohol consumption as a cause of cancer

BACKGROUND AND AIMS

There is increasing research evidence about the causal role of alcohol in cancer, accompanied by unclear and conflicting messages in the media. This paper aimed to clarify the strength of the evidence for alcohol as a cause of cancer, and the meaning of cause in this context.

METHODS

Recent epidemiological and biological research on alcohol and cancer was reviewed and summarized, drawing upon published meta-analyses identified from the Medline database and the archives of the International Agency for Research on Cancer. More recent epidemiological studies not included in these publications were also reviewed. A brief description of the nature of causal inference in epidemiology was used to frame discussion of the strength of the evidence that alcohol causes cancer, and contrast this with the case for a protective association of alcohol with cardiovascular disease.

RESULTS

The usual epidemiological understanding of a cause is a factor that increases the incidence of a condition in the population. In the context of a body of epidemiological evidence of an association of alcohol consumption with a disease, the inference that it is a causal association requires alternative explanations of the observed finding to be judged unlikely. Even without complete knowledge of biological mechanisms, the epidemiological evidence can support the judgement that alcohol causes cancer of the oropharynx, larynx, oesophagus, liver, colon, rectum and breast. The measured associations exhibit gradients of effect that are biologically plausible, and there is some evidence of reversibility of risk in laryngeal, pharyngeal and liver cancers when consumption ceases. The limitations of cohort studies mean that the true effects may be somewhat weaker or stronger than estimated currently, but are unlikely to be qualitatively different. The same, or similar, epidemiological studies also commonly report protection from cardiovascular disease associated with drinking but a high level of scepticism regarding these findings is now warranted.

CONCLUSIONS

There is strong evidence that alcohol causes cancer at seven sites in the body and probably others. Current estimates suggest that alcohol-attributable cancers at these sites make up 5.8% of all cancer deaths world-wide. Confirmation of specific biological mechanisms by which alcohol increases the incidence of each type of cancer is not required to infer that alcohol is a cause.

The Effect of Reference Group Classification and Change in Alcohol Consumption on the Association Between Alcohol Consumption and Cardiovascular Disease

BACKGROUND

Many studies suggest that mild alcohol consumption can help avert cardiovascular disease (CVD). This study investigated the association between alcohol consumption and CVD incidence, and assessed whether this differed by reference group classification. As alcohol consumption amounts may change over time, the results of simple and time-dependent analyses were compared.

METHODS

Data were from a community-based cohort study on 40- to 69-year-old Koreans recruited in 2001 to 2002. A total of 8,330 participants were followed up for 10 years and classed as nondrinkers (0 g/d), drinker group 1 (<15 g/d), and drinker group 2 (≥15 g/d). The risk of CVD, including myocardial infarction and coronary artery disease, was compared among groups using simple and time-dependent Cox analysis. Occasional drinkers (<2.5 g/d), nondrinkers, and lifetime abstainers were used as comparison reference groups.

RESULTS

Simple Cox analysis indicated that drinker group 1 exhibited a significantly lower risk of myocardial infarction (hazard ratio [HR]: 0.44, 95% confidence interval [CI]: 0.21, 0.92) and coronary artery disease (HR: 0.61, 95% CI: 0.4, 0.94) than nondrinkers. Time-dependent analysis based on alcohol consumption change showed that the beneficial effects of drinker group 1 were significant only for myocardial infarction, not for coronary artery disease. The benefits did not change significantly when either nondrinkers or lifetime abstainers were the reference group. However, when occasional drinkers were included in the reference group, the benefits of drinker group 1 were not significant for myocardial infarction (HR: 0.65, 95% CI: 0.29, 1.45) or coronary artery disease (HR: 0.71, 95% CI: 0.42, 1.19). Occasional drinkers and drinkers had more similar sociodemographic characteristics than did nondrinkers and drinkers.

CONCLUSIONS

Further studies on alcohol consumption and its effects on health must use repeated measurement to define drinking status, as simple and time-dependent analyses can show different alcohol consumption risks. These findings do not indicate a beneficial effect of drinking <15 g/d when occasional drinkers and nondrinkers are included in the reference group.

Is alcohol consumption a risk factor for prostate cancer? A systematic review and meta-analysis

BACKGROUND

Research on a possible causal association between alcohol consumption and risk of prostate cancer is inconclusive. Recent studies on associations between alcohol consumption and other health outcomes suggest these are influenced by drinker misclassification errors and other study quality characteristics. The influence of these factors on estimates of the relationship between alcohol consumption and prostate cancer has not been previously investigated.

METHODS

PubMed and Web of Science searches were made for case-control and cohort studies of alcohol consumption and prostate cancer morbidity and mortality (ICD-10: C61) up to December 2014. Studies were coded for drinker misclassification errors, quality of alcohol measures, extent of control for confounding and other study characteristics. Mixed models were used to estimate relative risk (RR) of morbidity or mortality from prostate cancer due to alcohol consumption with study level controls for selection bias and confounding.

RESULTS

A total of 340 studies were identified of which 27 satisfied inclusion criteria providing 126 estimates for different alcohol exposures. Adjusted RR estimates indicated a significantly increased risk of prostate cancer among low (RR = 1.08, P < 0.001), medium (RR = 1.07, P < 0.01), high (RR = 1.14, P < 0.001) and higher (RR = 1.18, P < 0.001) volume drinkers compared to abstainers. There was a significant dose-response relationship for current drinkers (Ptrend < 0.01). Studies free from misclassification errors produced the highest risk estimates for drinkers versus abstainers in adjusted models (RR = 1.22, P < 0.05).

CONCLUSION

Our study finds, for the first time, a significant dose-response relationship between level of alcohol intake and risk of prostate cancer starting with low volume consumption (>1.3, <24 g per day). This relationship is stronger in the relatively few studies free of former drinker misclassification error. Given the high prevalence of prostate cancer in the developed world, the public health implications of these findings are significant. Prostate cancer may need to be incorporated into future estimates of the burden of disease alongside other cancers (e.g. breast, oesophagus, colon, liver) and be integrated into public health strategies for reducing alcohol related disease.

Population Attributable and Preventable Fractions: Cancer Risk Factor Surveillance, and Cancer Policy Projection

The proportions of new cancer cases and deaths that are caused by exposure to risk factors and that could be prevented are key statistics for public health policy and planning. This paper summarizes the methodologies for estimating, challenges in the analysis of, and utility of, population attributable and preventable fractions for cancers caused by major risk factors such as tobacco smoking, dietary factors, high body fat, physical inactivity, alcohol consumption, infectious agents, occupational exposure, air pollution, sun exposure, and insufficient breastfeeding. For population attributable and preventable fractions, evidence of a causal relationship between a risk factor and cancer, outcome (such as incidence and mortality), exposure distribution, relative risk, theoretical-minimum-risk, and counterfactual scenarios need to be clearly defined and congruent. Despite limitations of the methodology and the data used for estimations, the population attributable and preventable fractions are a useful tool for public health policy and planning.

Alcohol Use and Breast Cancer: A Critical Review

The objective of this study was to outline the biological pathways of alcohol-attributable breast cancer, the epidemiological risk relationship between alcohol consumption and breast cancer, and the global burden of breast cancer incidence and mortality attributable to alcohol consumption, with a focus on light drinking. First, the literature regarding the biological mechanisms of how alcohol affects the risk of breast cancer was reviewed and summarized. Second, a search of meta-analyses that evaluated the risk relationship between alcohol consumption and breast cancer was conducted. Last, the burden of alcohol-attributable breast cancer incidence and mortality was estimated by means of a Population-Attributable Fraction methodology. Data on alcohol consumption were obtained from the Global Information System on Alcohol and Health, and data on cancer incidence and mortality were obtained from the GLOBOCAN database. Alcohol consumption affects breast cancer risk through the alteration in hormone levels and the associated biological pathways, the metabolism of ethanol resulting in carcinogens, and the inhibition of the one carbon metabolism pathway. The systematic review found 15 meta-analyses on the risk relationship between alcohol consumption (also light consumption) and the risk of breast cancer. All but 2 of these analyses showed a dose-response relationship between alcohol consumption and the risk of breast cancer. An estimated 144,000 (95% confidence interval [CI]: 88,000 to 200,000) breast cancer cases and 38,000 (95% CI: 2,400 to 53,000) breast cancer deaths globally in 2012 were attributable to alcohol, with 18.8% of these cases and 17.5% of these deaths affecting women who were light alcohol consumers. All levels of evidence showed a risk relationship between alcohol consumption and the risk of breast cancer, even at low levels of consumption. Due to this strong relationship, and to the amount of alcohol consumed globally, the incidence of and mortality from alcohol-attributable breast cancer is large.

The relationship between mild alcohol consumption and mortality in Koreans: a systematic review and meta-analysis

Background

A recent systematic review reported that mild drinking showed beneficial effects on mortality. However, this relationship between alcohol consumption and mortality differs by race, and there are few studies on Koreans. In this study, we reviewed previous studies conducted on Koreans to investigate the association between mild drinking and mortality.

Methods

Four databases (Medline, Web of Science, KoreaMed, and DBpia) were searched. Studies investigating the risk of alcohol consumption on three types of mortality (all-cause mortality, cancer-related mortality, and cardiovascular mortality) for Koreans were included.

Results

A total of 16 studies assessed alcohol consumption as a risk factor for mortality. Nine studies reported on the risk of alcohol consumption in relation to all-cause mortality, eight to cancer-related mortality, and three to cardiovascular mortality. Among these, only studies assessing alcohol amount not drink status or drink frequency were included in meta-analysis. The results of the meta-analysis did not show a significant effect of mild alcohol consumption on all-cause mortality (5 studies, OR: 0.85, 95 % CI: 0.72, 1.01). While meta-analysis of studies using all-cancer mortality showed significant effect of alcohol consumption (4 studies, OR: 0.89, 95 % CI: 0.85, 0.94), results of studies including all-caner and specific type of cancer was not significant (7 studies, OR: 1.02, 95 % CI: 0.9, 1.15). Although a meta-analysis of cardiovascular mortality could not be conducted owing to a lack of studies, all studies reported a non-significant effect of occasional or mild alcohol consumption.

Discussion

In this study, mild alcohol consumption in Korean did not show beneficial effect on mortality and it might be caused by three factors: criterion of mild drinking, the subjects, and sample size. The criterion of mild alcohol consumption was diverse in included studies. The effect of alcohol consumption could differ based on subjects’ sex, age as well as race. In addition, the effect of alcohol consumption might be different from previous one due to the small number of studies.

Conclusions

Mild alcohol consumption did not show any beneficial effects in relation to all-cause, cancer-related, and cardiovascular mortality. Additional studies are necessary to verify any association between mild drinking and mortality in Koreans.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2263-7) contains supplementary material, which is available to authorized users.

Inconsistency in reporting abstention and heavy drinking frequency: associations with sex and socioeconomic status, and potential impacts

AIMS

To describe inconsistencies in reporting past-year drinking status and heavy drinking occasions (HDOs) on single questions from two different instruments, and to identify associated characteristics and impacts.

METHODS

We compared computer-presented Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) with categorical response options, and mental health interview (MHI) with open-ended consumption questions, completed on the same day. Participants were 464 men and 459 women aged 38 (91.7% of surviving birth cohort members). Differences in dichotomous single-item measures of abstention and HDO frequency, associations of inconsistent reporting with sex, socioeconomic status (SES) and survey order, and impacts of instrument choice on associations of alcohol with sex and SES were examined.

RESULTS

The AUDIT-C drinking frequency question estimated higher past-year abstention prevalence (AUDIT = 7.6%, MHI = 5.4%), with one-third of AUDIT-C abstainers being MHI drinkers. Only AUDIT-C produced significant sex differences in abstainer prevalence. Inconsistencies in HDO classifications were bidirectional, but with fewer HDOs reported on the MHI than AUDIT-C question. Lower SES was associated with inconsistency in abstention and weekly+ HDOs. Abstention and higher HDO frequency were associated with lower SES overall, but sex-specific associations differed by instrument.

CONCLUSIONS

In this context, data collection method affected findings, with inconsistencies in abstention reports having most impact. Future studies should: (a) confirm self-reported abstention; (b) consider piloting data collection methods in target populations; (c) expect impacts of sex and SES on measurements and analyses.