Evaluation of confounding in epidemiologic studies assessing alcohol consumption on the risk of ischemic heart disease

Covariates in studies examining longitudinal relationships between substance use and mental health problems among youth: A meta-epidemiologic review

INTRODUCTION

This meta-epidemiological review examines covariate selection and reporting practices in observational studies analyzing longitudinal relationships between youth substance use and mental health problems (internalizing and externalizing).

METHODS

Sixty-nine studies published in high-impact journals from 2018 to 2023 were included. Studies were included if they explored prospective relationships between substance use and mental health among youth (12-25 years) and used repeated measures designs. Data extraction focused on study characteristics, covariates and their selection methods, and reporting practices.

RESULTS

There were 574 covariates included across studies; 33 were included as moderators and 18 were included as mediators. At the study level, the most common covariate domains included demographics (90 % of included studies had at least one demographic, mostly sex), substance-related variables (67 %; mostly alcohol or smoking), internalizing symptoms (39 %; mostly depression), family-related variables (29 %; mostly parental substance use or mental illness), and externalizing symptoms (19 %; mostly conduct). 93 % of studies had unique sets of lower-order covariates. Across all studies (n = 69), only 35 % provided details for how, and why, all covariates were selected with only 12 % reporting selecting covariates a priori, and none being pre-registered. Only 60 % mentioned confounding and only 13 % mentioned risk of confounding in their conclusions.

CONCLUSIONS

The findings highlight the need for improved covariate selection and reporting practices. Establishing a core set of covariates and adhering to standardized reporting guidelines would enhance the comparability and reliability of research findings in this field. Researchers can use this review to identify and justify the inclusion and exclusion of commonly reported covariates when analyzing relationships between youth substance use and mental health problems.

Effect of long-term moderate red wine consumption in CD1 female mice

In the early 80s, the so-called "French paradox" was proposed, that is, a correlation between wine consumption, a diet rich in fats, and low mortality from coronary disease. Conversely, it is well established that excessive alcohol consumption increases the risk of cirrhosis and cancer, but few studies have investigated the effects of moderate alcohol consumption. However, all these conclusions were derived from epidemiological population studies that may be subject to distortions due to multiple factors. Here, the effect of moderate consumption of red wine on health throughout life was examined in a murine model. Different variables were evaluated in groups of female animals that were fed a standard or a fat diet throughout their adult life and given water, or wine or alcohol diluted in water in proportions similar to what is considered moderate consumption in humans. Our results showed few differences in most of the analyzed variables (body weight, liver profile and survival rate) between the different female mouse groups. The most remarkable findings were observed in the fat-diet groups that showed more frequent and severe liver lesions and a lower average ovarian weight. Moreover, moderate and prolonged ethanol consumption significantly affected telomere length only when the diet was high in fat, whereas wine consumption showed no difference compared to water, pointing to a possible predominant role of the compounds, particularly polyphenols present in wine. On the other hand, wine-drinking mice fed a fat diet had more oocytes than those in the ethanol-drinking group. Overall, our data suggest that long-term moderate red wine consumption does not substantially influence the health of female mice.

Evaluating agreement between individual nutrition randomised controlled trials and cohort studies - a meta-epidemiological study

BACKGROUND

In nutrition research, randomised controlled trials (RCTs) and cohort studies provide complementary evidence. This meta-epidemiological study aims to evaluate the agreement of effect estimates from individual nutrition RCTs and cohort studies investigating a highly similar research question and to investigate determinants of disagreement.

METHODS

MEDLINE, Epistemonikos, and the Cochrane Database of Systematic Reviews were searched from January 2010 to September 2021. We matched individual RCTs to cohort studies based on population, intervention/exposure, comparator, and outcome (PI/ECO) characteristics. Two reviewers independently extracted study characteristics and effect estimates and rated the risk of bias using RoB2 and ROBINS-E. Agreement of matched RCTs/cohort studies was analysed by pooling ratio of risk ratios (RRR) and difference of (standardised) mean differences (DSMD).

RESULTS

We included 64 RCT/cohort study pairs with 4,136,837 participants. Regarding PI/ECO similarity, 20.3% pairs were "more or less identical", 71.9% "similar but not identical" and 7.8% "broadly similar". Most RCTs were classified as "low risk of bias" (26.6%) or with "some concerns" (65.6%); cohort studies were mostly rated with "some concerns" (46.6%) or "high risk of bias" (47.9%), driven by inadequate control of important confounding factors. Effect estimates across RCTs and cohort studies were in high agreement (RRR 1.00 (95% CI 0.91-1.10, n = 54); and DSMD - 0.26 (95% CI - 0.87-0.35, n = 7)). In meta-regression analyses exploring determinants of disagreements, risk-of-bias judgements tend to have had more influence on the effect estimate than "PI/ECO similarity" degree.

CONCLUSIONS

Effect estimates of nutrition RCTs and cohort studies were generally similar. Careful consideration and evaluation of PI/ECO characteristics and risk of bias is crucial for a trustworthy utilisation of evidence from RCTs and cohort studies.

Tea intake and non-alcoholic fatty liver disease risk: A two-sample Mendelian randomization study

Background

Non-alcoholic fatty liver disease (NAFLD) is a major global health problem due to its great disease and economic burdens. Tea is a popular beverage consumed by billions of people.globally owing to its health benefits. However, the evidence regarding the association between tea intake and NAFLD risk is inconsistent.

Objective

To examine the genetically predicted causal association between tea intake and NAFLD risk using the two-sample Mendelian randomization (MR) method.

Methods

Single-nucleotide polymorphisms (SNPs) strongly associated with tea intake were obtained from a large dataset (N = 447,485) in the UK biobank, and summary-level genetic data for NAFLD (2,275 cases and 375,002 controls) were collected from the FinnGen consortium. The two-sample MR method was used to investigate the causal association between tea intake and NAFLD risk. The random-effects inverse-variance weighted (IVW) was used as the primary approach for estimating the causal effect, and MR Egger, weighted median, simple mode, and weighted mode were used to verify the robustness of the primary results.

Results

Twenty-four valid SNPs were selected as the instrumental variables for tea intake. The IVW results indicated that tea intake was not causally associated with NAFLD risk (Odds ratio: 1.48; 95 % confidence interval: 0.64, 3.43; p = 0.364); moreover, the results from other methods were consistent with this finding. A leave-one-out analysis further demonstrated the robustness of our results. No evidence of heterogeneity, outliers, or horizontal pleiotropy was found.

Conclusion

Our results do not support tea intake being causally associated with a decreased risk of NAFLD.

Alcohol consumption and its association with cancer, cardiovascular, liver and brain diseases: a systematic review of Mendelian randomization studies

Background

The health effects of alcohol consumption, particularly regarding potential protective benefits of light to moderate intake compared to abstinence, remain a subject of ongoing debate. However, epidemiological studies face limitations due to imprecise exposure measurements and the potential for bias through residual confounding and reverse causation. To address these limitations, we conducted a systematic review of Mendelian Randomization (MR) studies examining the causal relationship between alcohol consumption and cancers, cardiovascular, liver, and neurological diseases.

Methodology

We searched PubMed, ScienceDirect and Embase and Europe PMC up to 05/2024 for MR studies investigating the association of genetically predicted alcohol consumption with cancers, cardiovascular, liver and neurological diseases. We assessed methodological quality based on key elements of the MR design a genetic association studies tool.

Results

We included 70 MR studies that matched our inclusion criteria. Our review showed a significant association of alcohol consumption with multiple cancers such as oral and oropharyngeal, esophageal, colorectal cancers, hepatocellular carcinoma and cutaneous melanoma. While the available studies did not consistently confirm the adverse or protective effects of alcohol on other cancers, such as lung cancer, as suggested by observational studies. Additionally, MR studies confirmed a likely causal effect of alcohol on the risk of hypertension, atrial fibrillation, myocardial infraction and vessels disease. However, there was no evidence to support the protective effects of light to moderate alcohol consumption on cognitive function, Alzheimer's disease, and amyotrophic lateral sclerosis, as reported in observational studies while our review revealed an increased risk of epilepsy and multiple sclerosis. The available studies provided limited results on the link between alcohol consumption and liver disease.

Conclusions

Despite the valuable insights into the causal relationship between alcohol consumption and various health outcomes that MR studies provided, it is worth noting that the inconsistent ability of genetic instrumental variables to distinguish between abstainers, light and moderate drinkers makes it difficult to differentiate between U or J-shaped vs. linear relationships between exposure and outcome. Additional research is necessary to establish formal quality assessment tools for MR studies and to conduct more studies in diverse populations, including non-European ancestries.

Systematic Review Registration

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021246154, Identifier: PROSPERO (CRD42021246154).

Is there any association between the presence of biomarkers and apical periodontitis? A systematic review

This systematic review aimed to verify whether there is evidence of an association between apical periodontitis and the presence of systemic biomarkers. This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA. For this, the acronym PECO was used; population (P) of adult humans exposed (E) to the presence of apical periodontitis, compared (C) to adult humans without apical periodontitis, and the outcome (O) of the presence of biomarkers was observed. The articles were searched in PubMed, Scopus, Web of Science, LILACS, Cochrane Library, OpenGray, and Google Scholar grey databases. Subsequently, studies were excluded based on title, abstract, and full article reading, following the eligibility criteria. The methodological quality of the selected studies was evaluated using the Newcastle-Ottawa qualifier. After exclusion, 656 studies were identified, resulting in 17 final articles that were divided into case-control, cross-sectional, and cohort studies. Eight studies were considered to have a low risk of bias, one had a medium risk of bias, and eight had a high risk of bias. In addition, 12 articles evaluated biomarkers in blood plasma, four evaluated them in saliva, and only one evaluated them in gingival crevicular fluid. The results of these studies indicated an association between apical periodontitis and the systemic presence of biomarkers. These markers are mainly related to inflammation, such as interleukins IL-1, IL-2, and IL-6, oxidative markers, such as nitric oxide and superoxide anions, and immunoglobulins IgG and IgM.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier (CRD42023493959).

Is low-level alcohol consumption really health-protective? A critical review of approaches to promote causal inference and recent applications

Heavy and disordered alcohol consumption is a known risk factor for several health conditions and is associated with considerable disease burden. However, at low-to-moderate levels, evidence suggests that drinking is associated with reduced risk for certain health outcomes. Whether these findings represent genuine protective effects or mere methodological artifacts remains unclear, but has substantial consequences for policy and practice. This critical review introduces methodological advances capable of enhancing causal inference from observational research, focusing on the 'G-methods' and Mendelian Randomization. We also present and evaluate recent research applying these methods and compare findings to the existing evidence base. Future directions are proposed for improving our causal understanding of the relationships between alcohol and long-term health outcomes.

Grilling the data: application of specification curve analysis to red meat and all-cause mortality

OBJECTIVES

To present an application of specification curve analysis-a novel analytic method that involves defining and implementing all plausible and valid analytic approaches for addressing a research question-to nutritional epidemiology.

STUDY DESIGN AND SETTING

We reviewed all observational studies addressing the effect of red meat on all-cause mortality, sourced from a published systematic review, and documented variations in analytic methods (eg, choice of model, covariates, etc.). We enumerated all defensible combinations of analytic choices to produce a comprehensive list of all the ways in which the data may reasonably be analyzed. We applied specification curve analysis to data from National Health and Nutrition Examination Survey 2007 to 2014 to investigate the effect of unprocessed red meat on all-cause mortality. The specification curve analysis used a random sample of all reasonable analytic specifications we sourced from primary studies.

RESULTS

Among 15 publications reporting on 24 cohorts included in the systematic review on red meat and all-cause mortality, we identified 70 unique analytic methods, each including different analytic models, covariates, and operationalizations of red meat (eg, continuous vs quantiles). We applied specification curve analysis to National Health and Nutrition Examination Survey, including 10,661 participants. Our specification curve analysis included 1208 unique analytic specifications, of which 435 (36.0%) yielded a hazard ratio equal to or more than 1 for the effect of red meat on all-cause mortality and 773 (64.0%) less than 1. The specification curve analysis yielded a median hazard ratio of 0.94 (interquartile range: 0.83-1.05). Forty-eight specifications (3.97%) were statistically significant, 40 of which indicated unprocessed red meat to reduce all-cause mortality and eight of which indicated red meat to increase mortality.

CONCLUSION

We show that the application of specification curve analysis to nutritional epidemiology is feasible and presents an innovative solution to analytic flexibility.

Association between public health policies on alcohol and worldwide cancer, liver disease and cardiovascular disease outcomes

BACKGROUND & AIMS

The long-term impact of alcohol-related public health policies (PHPs) on disease burden is unclear. We aimed to assess the association between alcohol-related PHPs and alcohol-related health consequences.

METHODS

We conducted an ecological multi-national study including 169 countries. We collected data on alcohol-related PHPs from the WHO Global Information System of Alcohol and Health 2010. Data on alcohol-related health consequences between 2010-2019 were obtained from the Global Burden of Disease database. We classified PHPs into five items, including criteria for low, moderate, and strong PHP establishment. We estimated an alcohol preparedness index (API) using multiple correspondence analysis (0 lowest and 100 highest establishment). We estimated an incidence rate ratio (IRR) for outcomes according to API using adjusted multilevel generalized linear models with a Poisson family distribution.

RESULTS

The median API in the 169 countries was 54 [IQR 34.9-76.8]. The API was inversely associated with alcohol use disorder (AUD) prevalence (IRR 0.13; 95% CI 0.03-0.60; p = 0.010), alcohol-associated liver disease (ALD) mortality (IRR 0.14; 95% CI 0.03-0.79; p = 0.025), mortality due to neoplasms (IRR 0.09; 95% CI 0.02-0.40; p = 0.002), alcohol-attributable hepatocellular carcinoma (HCC) (IRR 0.13; 95% CI 0.02-0.65; p = 0.014), and cardiovascular diseases (IRR 0.09; 95% CI 0.02-0.41; p = 0.002). The highest associations were observed in the Americas, Africa, and Europe. These associations became stronger over time, and AUD prevalence was significantly lower after 2 years, while ALD mortality and alcohol-attributable HCC incidence decreased after 4 and 8 years from baseline API assessment, respectively (p <0.05).

CONCLUSIONS

The API is a valuable instrument to quantify the robustness of alcohol-related PHP establishment. Lower AUD prevalence and lower mortality related to ALD, neoplasms, alcohol-attributable HCC, and cardiovascular diseases were observed in countries with a higher API. Our results encourage the development and strengthening of alcohol-related policies worldwide.

IMPACT AND IMPLICATIONS

We first developed an alcohol preparedness index, an instrument to assess the existence of alcohol-related public policies for each country. We then evaluated the long-term association of the country's alcohol preparedness index in 2010 with the burden of chronic liver disease, hepatocellular carcinoma, other neoplasms, and cardiovascular disease. The strengthening of alcohol-related public health policies could impact long-term mortality rates from cardiovascular disease, neoplasms, and liver disease. These conditions are the main contributors to the global burden of disease related to alcohol use. Over time, this association has not only persisted but also grown stronger. Our results expand the preliminary evidence regarding the importance of public health policies in controlling alcohol-related health consequences.

Characterization and critical appraisal of physiotherapy intervention research in Nigeria: a systematic review

OBJECTIVES

Clinical research is the bedrock of clinical innovation, education and practice. We characterized and critically appraised physiotherapy clinical research to avoid implementing misleading research findings into practice and to task the Nigerian physiotherapy societies on responsible conduct of clinical research.

METHODS

This is a systematic review of articles published in English between 2009 and 2023. We started with 2009 because at least few Nigerian Physiotherapy school had commenced postgraduate (research) training by then. We searched Pubmed, Medline, Cumulative Index to Nursing and Allied Health Literature, Academic Search Complete, PsycINFO and African Journal Online, and reference lists of relevant articles. We Data were selected and extracted according to predesigned eligibility criteria and using a standardized data extraction table. Where appropriate, the Pedro and Cochrane ROBINS1 were used to examine the risk of bias.

RESULTS

A total of 76 Nigerian studies were included in this study. The mean age of the study participants was 46.7 ± 8.6 years. Approximately, 45% of the participants were males. Of the clinical experiments, the randomized controlled trial (RCT) was the most common design (87.5%). Musculoskeletal conditions (39.3%) were the most studied disorder. Approximately 86% of the RCT had studies possessed fair to good quality. Interventions constituted exercise therapy (76.3%), manual therapy (8.5%) and electrotherapy (8.5%). More than half (67.8%) of the studies recorded medium to large effect sizes. A fair proportion (48.2%) of the studies had a confounding-by-indication bias. Approximately 43% of the clinical experiments were underpowered, and a few studies conducted normality tests (10.9%) and intention-to-treat analysis (37.5%).

CONCLUSIONS

RCT is the most frequent clinical experiment, with majority of them possessing fair to good quality. The most important flaws include improper computation of sample size, statistical analysis, absent intention-to-treat approach, among others. The magnitude of effects of Physiotherapy interventions varies from nil effect to large effect. Musculoskeletal condition is the most prevalent disorder and exercise is the most important intervention in Nigerian physiotherapy practice.

TRIAL REGISTRATION

We registered the protocol with PROSPERO. The registration number: CRD42021228514.

Association of health benefits and harms of Christmas dessert ingredients in recipes from The Great British Bake Off: umbrella review of umbrella reviews of meta-analyses of observational studies

OBJECTIVE

To determine the health benefits and harms of various ingredients in Christmas desserts from The Great British Bake Off.

DESIGN

Umbrella review of umbrella reviews of meta-analyses of observational studies.

DATA SOURCES

The Great British Bake Off website, Embase, Medline, and Scopus.

INCLUSION CRITERIA

Umbrella reviews of meta-analyses of observational studies evaluating the associations between Christmas dessert ingredients and the risk of death or disease.

MAIN OUTCOME MEASURES

Proportion of protective and harmful summary associations between ingredient groups from The Great British Bake Off Christmas dessert recipes and the risk of death or disease.

RESULTS

48 recipes for Christmas desserts (ie, cakes, biscuits, pastries, and puddings and desserts) were provided on The Great British Bake Off website with 178 unique ingredients that were collapsed into 17 overarching ingredient groups. A literature search identified 7008 titles and abstracts, of which 46 eligible umbrella reviews reported 363 unique summary associations between the ingredient groups and risk of death or disease. Of these summary associations, 149 (41%) were significant, including 110 (74%) that estimated that the ingredient groups reduced the risk of death or disease and 39 (26%) that increased the risk. The most common ingredient groups associated with a reduced risk of death or disease were fruit (44/110, 40%), coffee (17/110, 16%), and nuts (14/110, 13%), whereas alcohol (20/39, 51%) and sugar (5/39, 13%) were the most common ingredient groups associated with increased risk of death or disease.

CONCLUSIONS

Recipes for Christmas desserts from The Great British Bake Off often use ingredient groups that are associated with reductions, rather than increases, in the risk of death or disease. This Christmas, if concerns about the limitations of observational nutrition research are set aside, you can have your cake and eat it too.

Is there an association between periodontal disease and root caries? A systematic review and meta-analysis

Some periodontal diseases can be associated with cariogenic bacterial growth due to various oral health imbalances. This fact may be linked to a greater development of root caries. Thus, this systematic review analyzed the evidence on the association between periodontal disease and root caries. An electronic search was performed in five databases (Cochrane Library, LILACS, MedLine via PubMed, Scopus, and Web of Science) and two additional sources (Google Scholar and Open Grey) to partially capture the grey literature. The PECO strategy was used to identify prospective or retrospective observational studies assessing root caries in patients with periodontal disease without language or year publication restrictions. Two reviewers extracted data and evaluated the individual risk of bias in the eligible studies. Random effects meta-analyses were performed to calculate the Odds Ratio (OR). The risk of bias was assessed by the NIH tool, and the certainty of evidence was classified according to the GRADE tool. There were 1,725 studies retrieved, of which four met the eligibility criteria. All of them were evaluated for the control statements for possible confounders, bias consideration, and confounding factors because they had multivariate analysis. Adults with periodontal disease had a greater chance of presenting root caries than adults without, with OR 1.38 [CI 1.25, 1.53]. The certainty of evidence was classified as very low. Within the limits presented in this review, there was an association between periodontal disease and root caries, highlighted in the qualitative synthesis and the meta-analysis results.

Confounding in observational studies evaluating the association between Alzheimer's disease and periodontal disease: A systematic review

Background

Studies investigating the association between periodontitis and Alzheimer's disease (AD) suggested indirect (periodontitis would increase the circulation of inflammation-inducible molecules) and direct (periodontopathogens might colonize brains affected by Alzheimer's disease) pathways. While there seems to be a positive relationship between periodontitis and AD, concerns have been raised about the role of confounding.

Aim

To systematically review the literature to assess confounding and their level of heterogeneity in the association between periodontitis and AD. Also, to examine data reporting and interpretation regarding confounding bias.

Methods

This review followed the PRISMA guidelines and was registered within PROSPERO. Electronic searches were performed in seven main databases and three others to capture the "grey literature". The PECO strategy was used to identify observational studies (cross-sectional, case-control, or cohort studies) assessing the association between periodontal disease and AD without restricting publication language and year. Critical appraisal was performed according to the Joanna Briggs Institute guidelines. Confounders were evaluated following a two-step approach.

Results

A total of 3255 studies were found, of which 18 (13 case-control, four cross-sectional, and one cohort) met the eligibility criteria. Participants with AD were 1399 (mean age 64 ± 9 to 84.8 ± 5.6 years), whereas those without AD were 1730 (mean age 62.6 ± 7.1 to 81.4 ± 4.6). Female patients composed most of the sample for both groups. The confounding variables "age" and "sex" were present in all studies. Four studies used the 2017 AAP/EFP periodontal classification. Most studies had a low risk of bias. Fifty percent of the articles did not consider confounding; variation in the adjustment approaches was observed. Additionally, 62% of the studies did not mention bias, and 40% did not discuss any limitations about confounders.

Conclusions

Given the study's limitations, caution must be taken to properly interpret the association between periodontitis and AD.Registration: CRD42022293884.

Critical appraisal of confounding factors of observational studies on the association between dentofacial features and dental trauma in a Brazilian population

AIMS/OBJECTIVES

Dental trauma is a highly prevalent dental emergency. Children and adolescents without inadequate lip coverage, increased overjet, and anterior open bite are associated with the occurrence of traumatic dental injuries. Observational studies do not allow the inference of causality, one of the reasons being: the potential confounding factors. Therefore, this review aimed to critically appraise the confounding factors considered in epidemiological studies that associate dentofacial features with the occurrence of dental trauma in Brazilian children and adolescents.

METHODS

Studies included in the qualitative synthesis of a recently published comprehensive systematic review and meta-analysis on the topic were screened. Studies that only mentioned the performance of bivariate analyzes or that did not mention the performance of multivariate analyzes were excluded. Evaluation of control statements for possible confounders and bias consideration was performed for each selected study. Confounding factors in these studies were also identified and categorized according to their domains.

RESULTS

Fifty-five observational studies were screened, of which 11 were excluded due to the mention of only bivariate analyzes or the lack of multivariate analyses. The remaining 44 studies were critically appraised. Of these, 9 studies specifically mentioned the term confounding, and 12 studies mentioned the term bias. However, only 14 studies mentioned limitations on confounding factors in their findings. Among the 99 different variables identified, the most used were type of trauma, followed by sex and age.

CONCLUSION

Most studies did not acknowledge the control for possible confounding factors and rarely stressed the need for caution in interpreting their results. Cross-sectional studies do not allow inferring a cause-and-effect relationship between dentofacial features and dental trauma.

Perception of malocclusion and school performance in adolescents: a systematic review

This study aimed to assess the potential association between perception malocclusion and school performance in children and adolescents. An electronic search was performed in ten databases. Based on the PECO acronym (Population, Exposition, Comparator, and Outcome), the eligibility criteria included observational studies that compared the school performance of children and adolescents with and without the perception of malocclusion. There were no restrictions on the language or year of publication. Two reviewers selected the studies, extracted the data, and assessed the risk of bias by using the Joanna Briggs Institute tool for cross-sectional studies. School performance was measured by analyzing student grades; levels of absenteeism; and child or adolescent self-perception and/or the perception of parents, guardians, close friends, and teachers regarding the impact of malocclusion on school performance. The data were described narratively/descriptively. The search resulted in 3,581 registers, of which eight were included in the qualitative synthesis. These studies were published between 2007 and 2021. Two studies concluded that there was no significant association between school performance and perception of malocclusion, five studies found that only some of the children with malocclusion had their school performance affected, and one study concluded that there was a significant association between perception of malocclusion and low school performance. Considering all variables and the very low certainty of evidence, the perception of malocclusion seems to negatively impact school performance when associated with external and subjective factors. Further studies using additional measurement standards are required.

Population-level risks of alcohol consumption by amount, geography, age, sex, and year: a systematic analysis for the Global Burden of Disease Study 2020

BACKGROUND

The health risks associated with moderate alcohol consumption continue to be debated. Small amounts of alcohol might lower the risk of some health outcomes but increase the risk of others, suggesting that the overall risk depends, in part, on background disease rates, which vary by region, age, sex, and year.

METHODS

For this analysis, we constructed burden-weighted dose-response relative risk curves across 22 health outcomes to estimate the theoretical minimum risk exposure level (TMREL) and non-drinker equivalence (NDE), the consumption level at which the health risk is equivalent to that of a non-drinker, using disease rates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2020 for 21 regions, including 204 countries and territories, by 5-year age group, sex, and year for individuals aged 15-95 years and older from 1990 to 2020. Based on the NDE, we quantified the population consuming harmful amounts of alcohol.

FINDINGS

The burden-weighted relative risk curves for alcohol use varied by region and age. Among individuals aged 15-39 years in 2020, the TMREL varied between 0 (95% uncertainty interval 0-0) and 0·603 (0·400-1·00) standard drinks per day, and the NDE varied between 0·002 (0-0) and 1·75 (0·698-4·30) standard drinks per day. Among individuals aged 40 years and older, the burden-weighted relative risk curve was J-shaped for all regions, with a 2020 TMREL that ranged from 0·114 (0-0·403) to 1·87 (0·500-3·30) standard drinks per day and an NDE that ranged between 0·193 (0-0·900) and 6·94 (3·40-8·30) standard drinks per day. Among individuals consuming harmful amounts of alcohol in 2020, 59·1% (54·3-65·4) were aged 15-39 years and 76·9% (73·0-81·3) were male.

INTERPRETATION

There is strong evidence to support recommendations on alcohol consumption varying by age and location. Stronger interventions, particularly those tailored towards younger individuals, are needed to reduce the substantial global health loss attributable to alcohol.

FUNDING

Bill & Melinda Gates Foundation.

Causal inference for observational longitudinal studies using deep survival models

OBJECTIVE

Causal inference for observational longitudinal studies often requires the accurate estimation of treatment effects on time-to-event outcomes in the presence of time-dependent patient history and time-dependent covariates.

MATERIALS AND METHODS

To tackle this longitudinal treatment effect estimation problem, we have developed a time-variant causal survival (TCS) model that uses the potential outcomes framework with an ensemble of recurrent subnetworks to estimate the difference in survival probabilities and its confidence interval over time as a function of time-dependent covariates and treatments.

RESULTS

Using simulated survival datasets, the TCS model showed good causal effect estimation performance across scenarios of varying sample dimensions, event rates, confounding and overlapping. However, increasing the sample size was not effective in alleviating the adverse impact of a high level of confounding. In a large clinical cohort study, TCS identified the expected conditional average treatment effect and detected individual treatment effect heterogeneity over time. TCS provides an efficient way to estimate and update individualized treatment effects over time, in order to improve clinical decisions.

DISCUSSION

The use of a propensity score layer and potential outcome subnetworks helps correcting for selection bias. However, the proposed model is limited in its ability to correct the bias from unmeasured confounding, and more extensive testing of TCS under extreme scenarios such as low overlapping and the presence of unmeasured confounders is desired and left for future work.

CONCLUSION

TCS fills the gap in causal inference using deep learning techniques in survival analysis. It considers time-varying confounders and treatment options. Its treatment effect estimation can be easily compared with the conventional literature, which uses relative measures of treatment effect. We expect TCS will be particularly useful for identifying and quantifying treatment effect heterogeneity over time under the ever complex observational health care environment.

Are there non-linear relationships between alcohol consumption and long-term health?: a systematic review of observational studies employing approaches to improve causal inference

Background

Research has long found ‘J-shaped’ relationships between alcohol consumption and certain health outcomes, indicating a protective effect of moderate consumption. However, methodological limitations in most studies hinder causal inference. This review aimed to identify all observational studies employing improved approaches to mitigate confounding in characterizing alcohol–long-term health relationships, and to qualitatively synthesize their findings.

Methods

Eligible studies met the above description, were longitudinal (with pre-defined exceptions), discretized alcohol consumption, and were conducted with human populations. MEDLINE, PsycINFO, Embase and SCOPUS were searched in May 2020, yielding 16 published manuscripts reporting on cancer, diabetes, dementia, mental health, cardiovascular health, mortality, HIV seroconversion, and musculoskeletal health. Risk of bias of cohort studies was evaluated using the Newcastle-Ottawa Scale, and a recently developed tool was used for Mendelian Randomization studies.

Results

A variety of functional forms were found, including reverse J/J-shaped relationships for prostate cancer and related mortality, dementia risk, mental health, and certain lipids. However, most outcomes were only evaluated by a single study, and few studies provided information on the role of alcohol consumption pattern.

Conclusions

More research employing enhanced causal inference methods is urgently required to accurately characterize alcohol–long-term health relationships. Those studies that have been conducted find a variety of linear and non-linear functional forms, with results tending to be discrepant even within specific health outcomes.

Trial registration

PROSPERO registration number CRD42020185861.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01486-5.

A Systematic Review of MicroRNA Signatures Associated with the Progression of Leukoplakia with and without Epithelial Dysplasia

Oral cancer is a significant public health issue, being the eighth most common cancer worldwide with over 300,000 cases diagnosed annually. Early diagnosis and adequate management of oral potentially malignant disorders (OPMDs) before transformation into oral squamous cell carcinoma (OSCC) is critical to reduce deaths, morbidity, and to improve overall prognosis. MicroRNAs (miRNAs) are small noncoding RNAs involved in the post-transcriptional regulation of protein expression and implicated in the control of numerous cellular pathways and impacting physiological, developmental, and pathological processes. Dysregulation of miRNAs has been reported in many cancers and has been demonstrated to play a critical role in cancer initiation, progression, apoptosis, invasion and metastasis. This systematic review provides a comprehensive summary of the prevailing literature on miRNA signatures in OPMDs, specifically leukoplakia with or without oral epithelial dysplasia, and their utility in predicting malignant transformation into OSCC. Eighteen articles describing 73 unique and differentially expressed microRNAs met the criteria for inclusion in this review. We reviewed the characteristics and methodology for each of these studies and assessed the sensitivity and specificity of the studied miRNAs in predicting malignant transformation. This systematic review highlights the significant interest in miRNAs and their tremendous potential as prognostic markers for predicting the malignant transformation of OPMDs into OSCC.

Alcohol, cardiovascular disease and industry funding: A co-authorship network analysis of systematic reviews

BACKGROUND

Alcohol's effects on heart health is the site of a major scientific controversy. We conducted a co-authorship network analysis of systematic reviews on the impacts on alcohol on cardiovascular disease (CVD) in order to investigate patterns of co-authorship in the literature, with particular attention given to industry funding.

METHODS

We used Epistemonikos to identify systematic reviews. Review characteristics, influential authors, co-authorship subnetworks, prior histories of alcohol industry funding, study outcomes and citations were investigated.

RESULTS

60 systematic reviews with 231 unique authors met our inclusion criteria. 14 systematic reviews were undertaken by authors with histories of alcohol industry funding, including 5 that were funded directly by the alcohol industry itself. All 14 such reviews identified a cardioprotective effect of alcohol. These formed distinct co-authorship subnetworks within the literature. Of reviews by authors with no prior histories of alcohol industry funding, the findings were mixed, with 54% (25/46) concluding there was evidence of health protective effects. These two groups of reviews differed in other respects. Those with industry funding were more likely to study broader outcomes such as 'cardiovascular disease' or 'coronary heart disease' as opposed to specific CVD issues such as hypertension or stroke (93% [13/14] versus 41% [19/46]) (chi-squared 12.4, p < 0.001) and have more included studies (mean of 29 versus 20). They were also more widely cited by others. Over time the proportions of systematic reviews on CVD and alcohol undertaken by authors with no prior histories of alcohol industry funding has increased.

CONCLUSIONS

Systematic reviews undertaken by authors with histories of alcohol industry funding were more likely to study broader outcomes, and be cited more widely, and exclusively reported favorable conclusions.

Alcohol's Impact on the Cardiovascular System

Alcohol consumption has been shown to have complex, and sometimes paradoxical, associations with cardiovascular diseases (CVDs). Several hundred epidemiological studies on this topic have been published in recent decades. In this narrative review, the epidemiological evidence will be examined for the associations between alcohol consumption, including average alcohol consumption, drinking patterns, and alcohol use disorders, and CVDs, including ischaemic heart disease, stroke, hypertension, atrial fibrillation, cardiomyopathy, and heart failure. Methodological shortcomings, such as exposure classification and measurement, reference groups, and confounding variables (measured or unmeasured) are discussed. Based on systematic reviews and meta-analyses, the evidence seems to indicate non-linear relationships with many CVDs. Large-scale longitudinal epidemiological studies with multiple detailed exposure and outcome measurements, and the extensive assessment of genetic and confounding variables, are necessary to elucidate these associations further. Conflicting associations depending on the exposure measurement and CVD outcome are hard to reconcile, and make clinical and public health recommendations difficult. Furthermore, the impact of alcohol on other health outcomes needs to be taken into account. For people who drink alcohol, the less alcohol consumed the better.

[Benefit assessment of digital health applications-challenges and opportunities]

Digital health applications promise to improve patient health and medical care. This analysis provides a brief overview of evidence-based benefit assessment and the challenges to the underlying evidence as prerequisites for optimal patient-oriented decision making. Classical concepts in study design, recent developments, and innovative approaches are described with the aim of highlighting future areas of development in innovative study designs and strategic evaluation concepts for digital health applications. A special focus is on pragmatic study designs.Evidence-based benefit assessment has fundamental requirements and criteria regardless of the type of treatments evaluated. Reliable evidence is essential. Fast, efficient, reliable, and practice-relevant evaluation of digital health applications is not achieved by turning to nonrandomized trials, but rather by better pragmatic randomized trials. They are feasible and combine the characteristics of digital health applications, classical methodological concepts, and new approaches to study conduct. Routinely collected data, low-contact study conduct (remote trials, virtual trials), and digital biomarkers promote useful randomized real-world evidence as solid evidence base for digital health applications. Continuous learning evaluation with randomized designs embedded in routine care is key to sustainable and efficient benefit assessment of digital health applications and may be crucial for strategic improvement of healthcare.

Reaction Time and Visual Memory in Connection to Alcohol Use in Persons with Bipolar Disorder

The purpose of this study was to explore the association of cognition with hazardous drinking and alcohol-related disorder in persons with bipolar disorder (BD). The study population included 1268 persons from Finland with bipolar disorder. Alcohol use was assessed through hazardous drinking and alcohol-related disorder including alcohol use disorder (AUD). Hazardous drinking was screened with the Alcohol Use Disorders Identification Test for Consumption (AUDIT-C) screening tool. Alcohol-related disorder diagnoses were obtained from the national registrar data. Participants performed two computerized tasks from the Cambridge Automated Neuropsychological Test Battery (CANTAB) on A tablet computer: the 5-choice serial reaction time task, or reaction time (RT) test and the Paired Associative Learning (PAL) test. Depressive symptoms were assessed with the Mental Health Inventory with five items (MHI-5). However, no assessment of current manic symptoms was available. Association between RT-test and alcohol use was analyzed with log-linear regression, and eβ with 95% confidence intervals (CI) are reported. PAL first trial memory score was analyzed with linear regression, and β with 95% CI are reported. PAL total errors adjusted was analyzed with logistic regression and odds ratios (OR) with 95% CI are reported. After adjustment of age, education, housing status and depression, hazardous drinking was associated with lower median and less variable RT in females while AUD was associated with a poorer PAL test performance in terms of the total errors adjusted scores in females. Our findings of positive associations between alcohol use and cognition in persons with bipolar disorder are difficult to explain because of the methodological flaw of not being able to separately assess only participants in euthymic phase.

Associations of Binge Drinking With the Risks of Ischemic Heart Disease and Stroke: A Study of Pooled Norwegian Health Surveys

Norwegian health survey data (1987-2003) were analyzed to determine if binge drinking increases the risk of incident major events from ischemic heart disease (IHD) and stroke. Among current drinkers reporting average alcohol intakes of 2.00-59.99 g/day (n = 44,476), frequent binge drinking (≥5 units at least once per month) was not associated with a greater risk of IHD (adjusted hazard ratio (HR) = 0.91, 95% confidence interval (CI): 0.76, 1.09) or stroke (adjusted HR = 0.98, 95% CI: 0.81, 1.19), in comparison with participants who reported that they never or only infrequently (less than once per month) had episodes of binge drinking. Participants with an average alcohol intake of 2.00-59.99 g/day had a lower risk of IHD in comparison with participants with very low intakes (<2.00 g/day), both among frequent binge drinkers (adjusted HR = 0.67, 95% CI: 0.56, 0.80) and among never/infrequent binge drinkers (adjusted HR = 0.75, 95% CI: 0.67, 0.84). The findings suggest that frequent binge drinking, independent of average alcohol intake, does not increase the risk of incident IHD or stroke events. However, the findings should be interpreted in light of the limitations of the study design.

Reaction Time and Visual Memory in Connection with Alcohol Use in Schizophrenia and Schizoaffective Disorder

The purpose of this study was to explore the association between cognition and hazardous drinking and alcohol use disorder in schizophrenia and schizoaffective disorder. Cognition is more or less compromised in schizophrenia, and schizoaffective disorder and alcohol use might aggravate this phenomenon. The study population included 3362 individuals from Finland with diagnoses of schizophrenia or schizoaffective disorder. Hazardous drinking was screened with the AUDIT-C (Alcohol Use Disorders Identification Test for Consumption) screening tool. Alcohol use disorder (AUD) diagnoses were obtained from national registrar data. Participants performed two computerized tasks from the Cambridge Automated Neuropsychological Test Battery (CANTAB) on a tablet computer: The Five-Choice Serial Reaction Time Task (5-CSRTT) or the reaction time (RT) test and the Paired Associative Learning (PAL) test. The association between alcohol use and the RT and PAL tests was analyzed with log-linear regression and logistic regression, respectively. After adjustment for age, education, housing status, and the age at which the respondents had their first psychotic episodes, hazardous drinking was associated with a lower median RT in females and less variable RT in males, while AUD was associated with a poorer PAL test performance in terms of the total errors adjusted scores (TEASs) in females. Our findings of positive associations between alcohol and cognition in schizophrenia and schizoaffective disorder are unique.

A priori dietary patterns and cardiovascular disease incidence in adult population-based studies: a review of recent evidence

Cardiovascular disease (CVD) is the leading cause of death worldwide. Studies using the a priori dietary pattern approach have been criticized for the heterogeneity of their scoring methods. This review aimed to evaluate the evidence on the association between a priori dietary patterns and CVD incidence in recent adult population-based studies. Similar to the conclusions of previous systematic reviews and meta-analyses, our review found that the majority of recent studies suggested that Mediterranean diet (6 out of 10 studies), Dietary Approaches to Stop Hypertension diet (4 out of 6 studies), Dietary Guidelines-based (11 out of 13 studies) patterns, and other emerging dietary patterns, including carbohydrate quality, Dietary Inflammatory Index, Plant-based Diet Index and Healthy Nordic Food Index, were cardioprotective in the general population; however, there was substantial heterogeneity among the studies, possibly due to differences in scoring methods and analytical approaches used and inclusion of different confounders, as well as other methodological drawbacks, such as low numbers of cases and short follow-up periods. Future studies should simultaneously examine and compare multiple a priori dietary patterns in a specific population using a uniform statistical approach. A consensus on the scoring methods for each a priori dietary pattern is also necessary.

Association between patterns of alcohol consumption (beverage type, frequency and consumption with food) and risk of adverse health outcomes: a prospective cohort study

BACKGROUND

Alcohol consumption is a leading contributor to death and disability worldwide, but previous research has not examined the effects of different patterns of alcohol consumption. The study objective was to understand the relationship between different alcohol consumption patterns and adverse health outcomes risk, adjusting for average amount consumed among regular drinkers.

METHODS

This was a prospective cohort study of UK Biobank (UKB) participants. Abstainers, infrequent alcohol consumers or those with previous cancer, myocardial infarction (MI), stroke or liver cirrhosis were excluded. We used beverage type, consumption with food and consumption frequency as exposures and adjusted for potential confounding. All-cause mortality, major cardiovascular events-MACE (MI/stroke/cardiovascular death), accidents/injuries, liver cirrhosis, all-cause and alcohol-related cancer incidence over 9-year median follow-up period were outcomes of interest.

RESULTS

The final sample size for analysis was N = 309,123 (61.5% of UKB sample). Spirit drinking was associated with higher adjusted mortality (hazard ratio (HR) 1.25; 95% confidence intervals (CI) 1.14-1.38), MACE (HR 1.31; 95% CI 1.15-1.50), cirrhosis (HR 1.48; 95% CI 1.08-2.03) and accident/injuries (HR 1.10; 95% CI 1.03-1.19) risk compared to red wine drinking, after adjusting for the average weekly alcohol consumption amounts. Beer/cider drinkers were also at a higher risk of mortality (HR 1.18; 95% CI 1.10-1.27), MACE (HR 1.16; 95% CI 1.05-1.27), cirrhosis (HR 1.36; 95% CI 1.06-1.74) and accidents/injuries (HR 1.11; 95% CI 1.06-1.17). Alcohol consumption without food was associated with higher adjusted mortality (HR 1.10; 95% CI 1.02-1.17) risk, compared to consumption with food. Alcohol consumption over 1-2 times/week had higher adjusted mortality (HR 1.09; 95% CI 1.03-1.16) and MACE (HR 1.14; 95% CI 1.06-1.23) risk, compared to 3-4 times/week, adjusting for the amount of alcohol consumed.

CONCLUSION

Red wine drinking, consumption with food and spreading alcohol intake over 3-4 days were associated with lower risk of mortality and vascular events among regular alcohol drinkers, after adjusting for the effects of average amount consumed. Selection bias and residual confounding are important possible limitations. These findings, if replicated and validated, have the potential to influence policy and practice advice on less harmful patterns of alcohol consumption.