Exposure to breastfeeding and risk of developing multiple sclerosis
ConclusionOur study could not confirm previous findings of an association between breastfeeding and risk of MS. Breastfeeding information was less likely to be biased by knowledge of disease compared with case –control studies. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - May 15, 2021 Category: Epidemiology Source Type: research

Data Resource Profile: COVerAGE-DB: a global demographic database of COVID-19 cases and deaths
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - May 15, 2021 Category: Epidemiology Source Type: research

Commentary: Obstetric oxytocin exposure and risk of attention-deficit hyperactivity disorder and autism spectrum disorder in offspring —case closed
Synthetic oxytocin has been used in clinical practice for over 40  years to prevent maternal and perinatal mortality and morbidity. It is indicated for the augmentation and induction of labour in the antenatal setting, and for the prevention and treatment of uterine atony and haemorrhage in the postpartum setting.1 Endogenous oxytocin is involved in the regulation of stress, anxiety, social cognition and behaviours in humans. For years individuals have been debating whether oxytocin has potential harmful effects on child neurodevelopment, either directly by disrupting the oxytocinergic system or indirectly through u...
Source: International Journal of Epidemiology - May 15, 2021 Category: Epidemiology Source Type: research

Hello! How are we doing after one year of COVID-19?
Although prophecies of a new viral pandemic were common in infectious disease circles, SARS-CoV-2 was an unpleasant surprise for most epidemiologists. Its worldwide impact has been existential for many —and economic, social and psychological for all. ‘Epidemiology’ has entered the vernacular. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - April 11, 2021 Category: Epidemiology Source Type: research

Cohort Profiles: what are they good for?
TheIJE editorial team asked me to write about my views of the Cohort Profiles published in the journal, in light of a pilot study of the longevity and utility of the series.1 In the early phase of co-editingIJE, George Davey Smith and I looked at ways of improving communication, strengthening skills and learning from the history of epidemiology. Our first innovations were Point-Counterpoint discussions of controversial topics and Reprints and Reflections —re-publication of ‘IJE classics ’ which soon ran out,2 –4 and articles of significance that were not widely known due to being published in non-En...
Source: International Journal of Epidemiology - April 10, 2021 Category: Epidemiology Source Type: research

Corrigendum to: G-computation for policy-relevant effects of interventions on time-to-event outcomes
First published online: 3 November 2020,Int J Epidemiol 2020;49:2021 –29, doi:https://doi.org/10.1093/ije/dyaa156 (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - March 24, 2021 Category: Epidemiology Source Type: research

Planetary Health: Protecting Nature to Protect Ourselves. Samuel Myers and Howard Frumkin (eds)
Planetary Health: Protecting Nature to Protect Oourselves. MyersSamuelFrumkinHoward (eds). Washington, DC: Island Press, 2020, pp. 538. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - March 19, 2021 Category: Epidemiology Source Type: research

Has the IJE ’s Cohort Profile series achieved its aims?
TheIJE has a tradition of publishing information about collections of data on large cohorts with the aim of enabling epidemiological research workers with shared interests to learn about opportunities for collaboration. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - March 19, 2021 Category: Epidemiology Source Type: research

Cohort Profile Update: The Motorik-Modul (MoMo) Longitudinal Study —physical fitness and physical activity as determinants of health development in German children and adolescents
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - March 8, 2021 Category: Epidemiology Source Type: research

The role of C-reactive protein as a prognostic marker in COVID-19
ConclusionsThe distributional characteristics of CRP indicated an optimal cut-off of ≥40 mg/L was associated with mortality. This threshold may assist clinicians in using CRP as an early trigger for enhanced observation, treatment decisions and advanced care planning. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - March 3, 2021 Category: Epidemiology Source Type: research

Cohort Profile: The Collaborating Consortium of Cohorts Producing NIDA Opportunities (C3PNO)
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - March 2, 2021 Category: Epidemiology Source Type: research

Methods for estimating tuberculosis incidence and mortality by age and sex
AbstractAimsTo develop methods to disaggregate World Health Orgagnization estimates of tuberculosis (TB) incidence and mortality for each country by sex and age.MethodsFor countries where incidence estimates derived from a factor adjustment of notifications and case detection ratio over 0.85, or with
Source: International Journal of Epidemiology - February 24, 2021 Category: Epidemiology Source Type: research

COVID-19 antibody seroprevalence in Santa Clara County, California
ConclusionThe estimated prevalence of SARS-CoV-2 antibodies in Santa Clara County implies that COVID-19 was likely more widespread than indicated by the number of cases in late March, 2020. At the time, low-burden contexts such as Santa Clara County were far from herd-immunity thresholds. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - February 22, 2021 Category: Epidemiology Source Type: research

Erratum to: Cohort Profile: The Cohorts Consortium of Latin America and the Caribbean (CC-LAC) Cohorts Consortium of Latin America and the Caribbean (CC-LAC)
First published online: 5 September 2020,Int J Epidemiol 2020;49:1437 –1437g, doi:https://doi.org/10.1093/ije/dyaa073 (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - February 20, 2021 Category: Epidemiology Source Type: research

Characterizing a two-pronged epidemic in Mexico of non-communicable diseases and SARS-Cov-2: factors associated with increased case-fatality rates
AbstractBackgroundPeople with a previous diagnosis of non-communicable diseases (NCDs) are more likely to develop serious forms of COVID-19 or die. Mexico is the country with the fourth highest fatality rate from SARS-Cov-2, with high mortality in younger adults.ObjectivesTo describe and characterize the association of NCDs with the case-fatality rate (CFR) adjusted by age and sex in Mexican adults with a positive diagnosis for SARS-Cov-2.MethodsWe studied Mexican adults aged ≥20 years who tested positive for SARS-Cov-2 during the period from 28 February to 31 July 2020. The CFR was calculated and associations wi...
Source: International Journal of Epidemiology - February 15, 2021 Category: Epidemiology Source Type: research

Cohort Profile: The Shanghai Children ’s Health, Education and Lifestyle Evaluation, Preschool (SCHEDULE-P) study
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - February 12, 2021 Category: Epidemiology Source Type: research

Human papillomavirus vaccination and all-cause morbidity in adolescent girls: a cohort study of absence from school due to illness
ConclusionsOur study provides an important and novel contribution to HPV vaccine safety. Using absence from school records, we were able to address important safety concerns without relying on medical diagnoses. We conclude that HPV vaccination does not increase the risk of morbidity in any manner that manifests as absence from school due to illness. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - February 6, 2021 Category: Epidemiology Source Type: research

Corrigendum to: Epidemiological characteristics of patients with severe COVID-19 infection in Wuhan, China: evidence from a retrospective, observational study
First published online: 5 November 2020,Int J Epidemiol 2020;49:1940 –1950. doi:https://doi.org/10.1093/ije/dyaa180 (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - February 4, 2021 Category: Epidemiology Source Type: research

Worldwide burden of genital human papillomavirus infection in female sex workers: a systematic review and meta-analysis
ConclusionsOur findings suggest that FSWs are disproportionately affected by HPV, which is more pronounced in the Western Pacific and African regions, and are therefore in need of prevention, treatment and care services. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - February 1, 2021 Category: Epidemiology Source Type: research

Commentary: Challenges of COVID-19 screening of health care workers in Egypt and the Eastern Mediterranean region
The Eastern Mediterranean region has been severely affected by COVID-19. Countries have suffered from wave 3 of the COVID19/SARS-CoV-2 virus, after the first wave started in China and the second wave started in Europe. Good-quality data are lacking on the precise extent of infection. However, conditions that favour spread include large populations living in overcrowded cities (in Egypt especially given it is a country of close to 100 million people), inadequate healthcare and lack of transparency and accountability of governments.1 (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 27, 2021 Category: Epidemiology Source Type: research

Spicy food consumption and risk of gastrointestinal-tract cancers: findings from the China Kadoorie Biobank
AbstractBackgroundPrevious case –control studies have reported positive associations of spicy food consumption with risks of certain gastrointestinal-tract (GI) cancers. However, there is no prospective evidence on such associations, particularly from China, where there are high incidence rates of GI cancers and spicy food is wi dely consumed.MethodsThe prospective China Kadoorie Biobank study recruited>512  000 adults aged 30–79 years from 10 areas in China during 2004–2008; 2350 oesophageal, 3350 stomach and 3061 colorectal incident cancer cases were recorded by 1 January 2017, after a ...
Source: International Journal of Epidemiology - January 23, 2021 Category: Epidemiology Source Type: research

Erratum to: Mismatch between poor fetal growth and rapid postnatal weight gain in the first 2 years of life is associated with higher blood pressure and insulin resistance without increased adiposity in childhood: the GUSTO cohort study
First published online: 20 August 2020,Int J Epidemiol 2020;49:1591 –1603, doi:https://doi.org/10.1093/ije/dyaa143 (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 20, 2021 Category: Epidemiology Source Type: research

Educational note: Paradoxical collider effect in the analysis of non-communicable disease epidemiological data: a reproducible illustration and web application
First published online: 10 December 2019,Int J Epidemiol 2019; Volume 48, Issue 2, April 2019, Pages 640 –653. doi:https://doi.org/10.1093/ije/dyy275 (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 19, 2021 Category: Epidemiology Source Type: research

Cohort Profile Update: Manhi ça Health and Demographic Surveillance System (HDSS) of the Manhiça Health Research Centre (CISM)
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 16, 2021 Category: Epidemiology Source Type: research

Seroprevalence of SARS-CoV-2 antibodies in over 6000 healthcare workers in Spain
AbstractBackgroundSpain has one of the highest incidences of coronavirus disease 2019 (COVID-19) worldwide, so Spanish health care workers (HCW) are at high risk of exposure. Our objective was to determine severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seroprevalence amongst HCW and factors associated with seropositivity.MethodsA cross-sectional study evaluating 6190 workers (97.8% of the total workforce of a healthcare-system of 17 hospitals across four regions in Spain) was carried out between April and June 2020, by measuring immunoglobulin G (IgG)-SARS-CoV-2 antibody titres and related clinical d...
Source: International Journal of Epidemiology - January 12, 2021 Category: Epidemiology Source Type: research

Cohort Profile Update: Africa Centre Demographic Information System (ACDIS) and population-based HIV survey
South AfricaepidemiologyHIVpopulation cohort (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 12, 2021 Category: Epidemiology Source Type: research

International comparisons of COVID-19 deaths in the presence of comorbidities require uniform mortality coding guidelines
COVID-19classification of deathsmortality statisticsICD-10politicsnosologyWorld Health Organization (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 11, 2021 Category: Epidemiology Source Type: research

Reflection on modern methods: good practices for applied statistical learning in epidemiology
AbstractStatistical learning includes methods that extract knowledge from complex data. Statistical learning methods beyond generalized linear models, such as shrinkage methods or kernel smoothing methods, are being increasingly implemented in public health research and epidemiology because they can perform better in instances with complex or high-dimensional data —settings in which traditional statistical methods fail. These novel methods, however, often include random sampling which may induce variability in results. Best practices in data science can help to ensure robustness. As a case study, we included four sta...
Source: International Journal of Epidemiology - January 9, 2021 Category: Epidemiology Source Type: research

Associations of parental birth characteristics with autism spectrum disorder (ASD) risk in their offspring: a population-based multigenerational cohort study in Denmark
AbstractBackgroundFetal exposure risk factors are associated with increased autism spectrum disorder (ASD) risk. New hypotheses regarding multigenerational risk for ASD have been proposed, but epidemiological evidence is largely lacking. We evaluated whether parental birth characteristics, including preterm birth and low birthweight, were associated with ASD risk in offspring.MethodsWe conducted a nationwide register-based cohort study that included 230  174 mother-child and 157 926 father-child pairs in Denmark. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) f...
Source: International Journal of Epidemiology - January 7, 2021 Category: Epidemiology Source Type: research

Protein foods from animal sources, incident cardiovascular disease and all-cause mortality: a substitution analysis
ConclusionsNuts, whole grains, legumes and fish appeared to be healthier protein sources than eggs, processed meat, unprocessed red meat and poultry for preventing incident CVD and premature death. The magnitude of lower risk for incident CVD and all-cause mortality was driven by amount and number of animal protein foods substituted. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 7, 2021 Category: Epidemiology Source Type: research

Cohort Profile: The Singapore Epidemiology of Eye Diseases study (SEED)
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - January 4, 2021 Category: Epidemiology Source Type: research

Cohort Profile: Centro de Integra ção de Dados e Conhecimentos para Saúde (CIDACS) Birth Cohort
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 30, 2020 Category: Epidemiology Source Type: research

Cohort Profile: The St. Jude Lifetime Cohort Study (SJLIFE) for paediatric cancer survivors
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 29, 2020 Category: Epidemiology Source Type: research

The global burden of chronic hepatitis B virus infection: comparison of country-level prevalence estimates from four research groups
ConclusionCurrent prevalence estimates, particularly those from the WHO and the CDA based on more recent empirical data, provide a useful resource to assess the population-level burden of chronic HBV-infection. However, further seroprevalence data in young children are needed particularly in sub-Saharan Africa. This is a priority, as monitoring progress towards elimination depends on improved knowledge of prevalence in this age group. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 27, 2020 Category: Epidemiology Source Type: research

Corrigendum to: Joint effect of diabetes and opiate use on all-cause and cause-specific mortality: the Golestan cohort study
First published online: 18 August 2020,Int J Epidemiol 2020, doi: https://doi.org/10.1093/ije/dyaa126 (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 27, 2020 Category: Epidemiology Source Type: research

Long-term exposure to iron and copper in fine particulate air pollution and their combined impact on reactive oxygen species concentration in lung fluid: a population-based cohort study of cardiovascular disease incidence and mortality in Toronto, Canada
ConclusionsLong-term exposure to Fe and Cu in PM2.5 and their combined impact on ROS were consistently associated with increased CVD death. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 25, 2020 Category: Epidemiology Source Type: research

Cohort Profile: Research Advancement through Cohort Cataloguing and Harmonization (ReACH)
(Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 25, 2020 Category: Epidemiology Source Type: research

Data Resource Profile: Xiamen registry of pregnant women and offspring (REPRESENT): a population-based, long-term follow-up database linking four major healthcare data platforms
Key FeaturesREPRESENT is the first population-based, long-term follow-up database of pregnant women and their offspring in China that can capture information on a diversity of exposures before pregnancy as well as long-term outcomes for both mothers and infants, in addition to tracking data during gestation and delivery.In the past 11 years (January 2008 to March 2019), REPRESENT has accumulated data concerning 766  194 pregnancies and 765 746 newborns, with over 800 variables being documented from four healthcare data platforms in Xiamen, a sub-provincial city in southeast China that has 4.11 million residents.R...
Source: International Journal of Epidemiology - December 25, 2020 Category: Epidemiology Source Type: research

Is the effect of Mediterranean diet on hip fracture mediated through type 2 diabetes mellitus and body mass index?
ConclusionsMediterranean diet has a direct effect on hip fracture risk via pathways other than through T2DM and BMI. We cannot exclude mediating effects of T2DM or BMI, or that their effects cancel each other out. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 25, 2020 Category: Epidemiology Source Type: research

Educational note: addressing special cases of bias that frequently occur in perinatal epidemiology
AbstractThe epidemiologic study of pregnancy and birth outcomes may be hindered by several unique and challenging issues. Pregnancy is a time-limited period in which severe cohort attrition takes place between conception and birth and adverse outcomes are complex and multi-factorial. Biases span those familiar to epidemiologists: selection, confounding and information biases. Specific challenges include conditioning on potential intermediates, how to treat race/ethnicity, and influential windows of prolonged, seasonal and potentially time-varying exposures. Researchers studying perinatal outcomes should be cognizant of the...
Source: International Journal of Epidemiology - December 25, 2020 Category: Epidemiology Source Type: research

Epigenome-wide association study of diet quality in the Women ’s Health Initiative and TwinsUK cohort
This study assessed whether diet quality was associated with differential DNA methylation measured across 445  548 loci in the Women’s Health Initiative (WHI) and the TwinsUK cohort.DesignThe discovery cohort consisted of 4355 women from the WHI. The replication cohort consisted of 571 mono- and dizygotic twins from the TwinsUK cohort. DNA methylation was measured in whole blood using the Illumina Infinium HumanMethylation450 Beadchip. Diet quality was assessed using the Alternative Healthy Eating Index 2010 (AHEI-2010). A meta-analysis, stratified by study cohort, was performed using generalized linear models t...
Source: International Journal of Epidemiology - December 23, 2020 Category: Epidemiology Source Type: research

Reflection on modern methods: demystifying robust standard errors for epidemiologists
AbstractAll statistical estimates from data have uncertainty due to sampling variability. A standard error is one measure of uncertainty of a sample estimate (such as the mean of a set of observations or a regression coefficient). Standard errors are usually calculated based on assumptions underpinning the statistical model used in the estimation. However, there are situations in which some assumptions of the statistical model including the variance or covariance of the outcome across observations are violated, which leads to biased standard errors. One simple remedy is to userobust standard errors, which are robust to vio...
Source: International Journal of Epidemiology - December 22, 2020 Category: Epidemiology Source Type: research

Swedish snus use is associated with mortality: a pooled analysis of eight prospective studies
ConclusionsSnus use among men is associated with increased all-cause mortality, cardiovascular mortality, with death from other causes and possibly with increased cancer mortality. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 22, 2020 Category: Epidemiology Source Type: research

Heat-mortality risk and the population concentration of metropolitan areas in Japan: a nationwide time-series study
ConclusionsPopulation concentration in metropolitan areas intensified interregional disparities in demography, living environments, and medical services in Japan; these disparities were associated with higher heat-mortality risk. Our results can contribute to policies to reduce vulnerability to high temperatures. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 21, 2020 Category: Epidemiology Source Type: research

Investigating the causal effect of maternal vitamin B12 and folate levels on offspring birthweight
ConclusionsOur results are consistent with evidence from randomized controlled trials that higher maternal folate levels increase offspring birthweight. We did not find evidence for a causal effect of B12 levels on offspring birthweight, suggesting previous observational studies may have been confounded. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 21, 2020 Category: Epidemiology Source Type: research

Use of directed acyclic graphs (DAGs) to identify confounders in applied health research: review and recommendations
ConclusionThere is substantial variation in the use and reporting of DAGs in applied health research. Although this partly reflects their flexibility, it also highlights some potential areas for improvement. This review hence offers several recommendations to improve the reporting and use of DAGs in future research. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 17, 2020 Category: Epidemiology Source Type: research

Commentary: Dairy milk intake and breast cancer risk: does an association exist, and what might be the culprit?
In this issue of theIJE, Fraseret al. report findings on soy and dairy milk intake in relation to breast cancer risk in the Adventist Health Study-2 (AHS-2).1 The authors found that soy milk intake was not related to breast cancer risk, whereas higher dairy milk intake was related to a higher risk. This is a well-characterized cohort with a high proportion of vegetarians and vegans (around 36%), making it one of the best cohorts to assess the association between soy intake and breast cancer risk reliably in Western populations. Another related strength of this study is that around 8% of the cohort does not consume dairy mi...
Source: International Journal of Epidemiology - December 17, 2020 Category: Epidemiology Source Type: research

Erratum to: Cross-trait analyses with migraine reveal widespread pleiotropy and suggest a vascular component to migraine headache
The International Headache Genetics Consortium was omitted from the Author list and the list of additional authors and collborators was published as a supplementary file. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 17, 2020 Category: Epidemiology Source Type: research

Early-childhood cytomegalovirus infection and children ’s neurocognitive development
ConclusionIn this large-scale prospective cohort, we observed some evidence for adverse neurocognitive effects of postnatal CMV infection on general intelligence during early childhood, although not with lasting effect. If confirmed, these results could support the implementation of preventative measures to combat postnatal CMV infection. (Source: International Journal of Epidemiology)
Source: International Journal of Epidemiology - December 11, 2020 Category: Epidemiology Source Type: research