Dolly Baliunas

THE RELATION BETWEEN DIFFERENT DIMENSIONS OF ALCOHOL CONSUMPTION AND BURDEN OF DISEASE - AN OVERVIEW

AIMS As part of a larger study to estimate the global burden of disease and injury attributable to alcohol: to evaluate the evidence for a causal impact of average volume of alcohol consumption and pattern of drinking on diseases and injuries; to quantify relationships identified as causal based on published meta-analyses; to separate the impact on mortality versus morbidity where possible; and to assess the impact of the quality of alcohol on burden of disease. METHODS Systematic literature reviews were used to identify alcohol-related diseases, birth complications and injuries using standard epidemiological criteria to determine causality. The extent of the risk relations was taken from meta-analyses. RESULTS Evidence of a causal impact of average volume of alcohol consumption was found for the following major diseases: tuberculosis, mouth, nasopharynx, other pharynx and oropharynx cancer, oesophageal cancer, colon and rectum cancer, liver cancer, female breast cancer, diabetes mellitus, alcohol use disorders, unipolar depressive disorders, epilepsy, hypertensive heart disease, ischaemic heart disease (IHD), ischaemic and haemorrhagic stroke, conduction disorders and other dysrhythmias, lower respiratory infections (pneumonia), cirrhosis of the liver, preterm birth complications and fetal alcohol syndrome. Dose-response relationships could be quantified for all disease categories except for depressive disorders, with the relative risk increasing with increased level of alcohol consumption for most diseases. Both average volume and drinking pattern were linked causally to IHD, fetal alcohol syndrome and unintentional and intentional injuries. For IHD, ischaemic stroke and diabetes mellitus beneficial effects were observed for patterns of light to moderate drinking without heavy drinking occasions (as defined by 60+ g pure alcohol per day). For several disease and injury categories, the effects were stronger on mortality compared to morbidity. There was insufficient evidence to establish whether quality of alcohol had a major impact on disease burden. CONCLUSIONS Overall, these findings indicate that alcohol impacts many disease outcomes causally, both chronic and acute, and injuries. In addition, a pattern of heavy episodic drinking increases risk for some disease and all injury outcomes. Future studies need to address a number of methodological issues, especially the differential role of average volume versus drinking pattern, in order to obtain more accurate risk estimates and to understand more clearly the nature of alcohol-disease relationships.

Alcohol as a Risk Factor for Type 2 Diabetes A systematic review and meta-analysis

OBJECTIVE To clarify the dose-response relationship between alcohol consumption and type 2 diabetes. RESEARCH DESIGN AND METHODS A systematic computer-assisted and hand search was conducted to identify relevant articles with longitudinal design and quantitative measurement of alcohol consumption. Adjustment was made for the sick-quitter effect. We used fractional polynomials in a meta-regression to determine the dose-response relationships by sex and end point using lifetime abstainers as the reference group. RESULTS The search revealed 20 cohort studies that met our inclusion criteria. A U-shaped relationship was found for both sexes. Compared with lifetime abstainers, the relative risk (RR) for type 2 diabetes among men was most protective when consuming 22 g/day alcohol (RR 0.87 [95% CI 0.76–1.00]) and became deleterious at just over 60 g/day alcohol (1.01 [0.71–1.44]). Among women, consumption of 24 g/day alcohol was most protective (0.60 [0.52–0.69]) and became deleterious at about 50 g/day alcohol (1.02 [0.83–1.26]). CONCLUSIONS Our analysis confirms previous research findings that moderate alcohol consumption is protective for type 2 diabetes in men and women.

Alcohol as a risk factor for liver cirrhosis: a systematic review and meta-analysis.

INTRODUCTION AND AIMS Alcohol is an established risk factor for liver cirrhosis. It remains unclear, however, whether this relationship follows a continuous dose-response pattern or has a threshold. Also, the influences of sex and end-point (i.e. mortality vs. morbidity) on the association are not known. To address these questions and to provide a quantitative assessment of the association between alcohol intake and risk of liver cirrhosis, we conducted a systematic review and meta-analysis of cohort and case-control studies. DESIGN AND METHODS Studies were identified by a literature search of Ovid MEDLINE, EMBASE, Web of Science, CINAHL, PsychINFO, ETOH and Google Scholar from January 1980 to January 2008 and by searching the references of retrieved articles. Studies were included if quantifiable information on risk and related confidence intervals with respect to at least three different levels of average alcohol intake were reported. Both categorical and continuous meta-analytic techniques were used to model the dose-response relationship. RESULTS Seventeen studies met the inclusion criteria. We found some indications for threshold effects. Alcohol consumption had a significantly larger impact on mortality of liver cirrhosis compared with morbidity. Also, the same amount of average consumption was related to a higher risk of liver cirrhosis in women than in men. DISCUSSION AND CONCLUSIONS Overall, end-point was an important source of heterogeneity among study results. This result has important implications not only for studies in which the burden of disease attributable to alcohol consumption is estimated, but also for prevention.

Alcohol consumption and the risk of morbidity and mortality for different stroke types - a systematic review and meta-analysis

BackgroundObservational studies have suggested a complex relationship between alcohol consumption and stroke, dependent on sex, type of stroke and outcome (morbidity vs. mortality). We undertook a systematic review and a meta-analysis of studies assessing the association between levels of average alcohol consumption and relative risks of ischemic and hemorrhagic strokes separately by sex and outcome. This meta-analysis is the first to explicitly separate morbidity and mortality of alcohol-attributable stroke and thus has implications for public health and prevention.MethodsUsing Medical Subject Headings (alcohol drinking, ethanol, cerebrovascular accident, cerebrovascular disorders, and intracranial embolism and thrombosis and the key word stroke), a literature search of MEDLINE, EMBASE, CINAHL, CABS, WHOlist, SIGLE, ETOH, and Web of Science databases between 1980 to June 2009 was performed followed by manual searches of bibliographies of key retrieved articles. From twenty-six observational studies (cohort or case-control) with ischemic or hemorrhagic strokes the relative risk or odds ratios or hazard ratios of stroke associated with alcohol consumption were reported; alcohol consumption was quantified; and life time abstention (manually estimated where data for current abstainers were given) was used as the reference group. Two reviewers independently extracted the information on study design, participant characteristics, level of alcohol consumption, stroke outcome, control for potential confounding factors, risk estimates and key criteria of study quality using a standardized protocol.ResultsThe dose-response relationship for hemorrhagic stroke had monotonically increasing risk for increasing consumption, whereas ischemic stroke showed a curvilinear relationship, with a protective effect of alcohol for low to moderate consumption, and increased risk for higher exposure. For more than 3 drinks on average/day, in general women had higher risks than men, and the risks for mortality were higher compared to the risks for morbidity.ConclusionsThese results indicate that heavy alcohol consumption increases the relative risk of any stroke while light or moderate alcohol consumption may be protective against ischemic stroke. Preventive measures that should be initiated are discussed.

Causal considerations on alcohol and HIV/AIDS--a systematic review.

AIM The study aimed to explore the possible causal nature of the association between alcohol consumption and HIV/AIDS. METHODS A review based on meta-analyses and reviews was conducted according to standard epidemiological criteria to distinguish causality from association, examining (i) the potential impact of alcohol on the incidence of HIV and (ii) alcohols impact on worsening the disease course. RESULTS In terms of incidence of HIV, although we found a consistent and strong association with consumption, there was not enough evidence for a causal connection. In particular, it is not clear whether personality traits such as sensation seeking or sexual compulsivity and psychiatric disorders such as antisocial personality disorder impact both alcohol consumption and risky sex, subsequently creating an association between both behaviors. In terms of worsening the disease course of HIV/AIDS, we found enough evidence for a causal impact of alcohol. Alcohol affects the immune system, thus contributing to a worsened course of HIV/AIDS. In addition, alcohol negatively impacts on behaviors that include support seeking and medication adherence. CONCLUSIONS A randomized controlled clinical trial targeted toward at-risk HIV-negative individuals who live in areas with high HIV prevalence is suggested to test the effects of proven effective alcohol interventions on HIV incidence.

Alcohol consumption and risk of incident human immunodeficiency virus infection: a meta-analysis

ObjectiveTo analyze the relationship between alcohol consumption and incident HIV infection.MethodsArticles were identified via electronic and hand searches. Inclusion criteria were: incident HIV infection, preceding alcohol consumption, and association relating the two. The DerSimonian and Laird random effects model was used. For studies with more than one estimate of a given type, estimates were combined using the inverse variance weighted method. Publication bias was assessed using Begg’s and Egger’s tests. Heterogeneity was assessed using Q and I2 statistics.ResultsTen studies were included. Overall alcohol consumption (any of the three types identified) increased the risk of HIV (RR 1.98, 95% CI 1.59–2.47). Alcohol consumers were at 77% higher risk (RR 1.77, 95% CI 1.43–2.19). Those consuming alcohol prior to, or at the time of, sexual relations were at an 87% increased risk (RR 1.87, 95% CI 1.39–2.50). For binge drinkers, the risk was double that of non-binge drinkers (RR 2.20, 95% CI 1.29–3.74).ConclusionsAlcohol consumption is associated with an increased risk of incident HIV infection. Additional research is required to further investigate a possible causal role.

Alcohol and hypertension: gender differences in dose-response relationships determined through systematic review and meta-analysis.

AIMS To analyze the dose-response relationship between average daily alcohol consumption and the risk of hypertension via systematic review and meta-analysis. DESIGN A computer-assisted search was completed for 10 databases, followed by hand searches of relevant articles. Only studies with longitudinal design, quantitative measurement of alcohol consumption and biological measurement of outcome were included. Dose-response relationships were assessed by determining the best-fitting model via first- and second-degree fractional polynomials. Various tests for heterogeneity and publication bias were conducted. FINDINGS A total of 12 cohort studies were identified from the literature from the United States, Japan and Korea. A linear dose-response relationship with a relative risk of 1.57 at 50 g pure alcohol per day and 2.47 at 100 g per day was seen for men. Among women, the meta-analysis indicated a more modest protective effect than reported previously: a significant protective effect was reported for consumption at or below about 5 g per day, after which a linear dose-response relationship was found with a relative risk of 1.81 at 50 g per day and of 2.81 at an average daily consumption of 100 g pure alcohol per day. Among men, Asian populations had higher risks than non-Asian populations. CONCLUSIONS The risk for hypertension increases linearly with alcohol consumption, so limiting alcohol intake should be advised for both men and women.

Illicit opioid use in Canada: Comparing social, health, and drug use characteristics of untreated users in five cities (OPICAN study)

Most of the estimated 125,000 injection drug users (IDUs) in Canada use illicit opioids and are outside treatment (i.e., methadone maintenance treatment). Empirical data suggest that illicit opioid users outside treatment are characterized by various health and social problem characteristics, including polydrug use, physical and mental morbidity, social marginalization, and crime. Although required for evidence-based programming, systematic information on this specific substance-user population is sparse in Canada to date. This article presents and compares key characteristics of population of illicit opioid users outside treatment in five cities across Canada (OPICAN cohort). Overall, the majority of OPICAN participants regularly used both a variety of illicit opioids and cocaine or crack, reported physical and mental health (e.g., mood disorder) problems, lacked permanent housing, were involved in crime, and had their “ideal” treatment not available to them. However, key local sample differences were shown, including patterns of heroin versus prescription opioid use and levels of additional cocaine versus crack use as well as indicators of social marginalization. Illicit opioid user population across Canada differ on key social, health, and drug use indicators that are crucial for interventions and are often demonstrated between larger and smaller city sites. Differentiated interventions are required.

Determinants of overdose incidents among illicit opioid users in 5 Canadian cities

Background: Drug overdose is a major cause of death and illness among illicit drug users. Previous research has indicated that most illicit drug users experience nonfatal overdoses and has suggested a variety of factors that are associated with risk of overdose. In this study, we examined the occurrence of and the factors associated with nonfatal overdoses within a Canadian sample of illicit opioid users not enrolled in treatment at the time of study recruitment. Methods: Interviewers used a standard questionnaire to collect data on sociodemographic characteristics, drug use, health and health care, experience in the criminal justice system and treatment for drug problems; they also performed standard assessments for mental health and infectious disease. The association between overdose and sociodemographic and drug-use factors was examined with χ2 and t test analyses; marginally significant variables were examined with logistic regression to determine independent effects. Results: A total of 679 subjects were interviewed; 651 provided answers sufficient for this analysis. One hundred and twelve (17.2%) of the 651 respondents reported an overdose episode in the previous 6 months. In the logistic regression analysis (after adjustment for sociodemographic factors), homelessness, noninjection use of hydromorphone in the past 30 days and involvement in drug treatment in the past 12 months were predictors of overdose (p < 0.05). Interpretation: Overdose poses a considerable health risk for illicit opioid users. We found that a diverse set of factors was associated with overdose episodes. Prevention efforts will likely be more effective if they can be directed to specific causal factors.

Smoking-attributable morbidity: acute care hospital diagnoses and days of treatment in Canada, 2002

BackgroundSmoking is one of the most important risk factors for burden of disease. Our objective was to estimate the number of hospital diagnoses and days of treatment attributable to smoking for Canada, 2002.MethodsDistribution of exposure was taken from a major national survey of Canada, the Canadian Community Health Survey. For chronic diseases, risk relations were taken from the published literature and combined with exposure to calculate age- and sex-specific smoking-attributable fractions (SAFs). For fire deaths, SAFs were taken directly from available statistics. Information on morbidity, with cause of illness coded according to the International Classification of Diseases version 10, was obtained from the Canadian Institute for Health Information.ResultsFor Canada in 2002, 339,179 of all hospital diagnoses were estimated to be attributable to smoking and 2,210,155 acute care hospital days. Ischaemic heart disease was the largest single category in terms of hospital days accounting for 21 percent, followed by lung cancer at 9 percent. Smoking-attributable acute care hospital days cost over