Overcoming Data Gaps in Life Course Epidemiology by Matching Across Cohorts.

Life course epidemiology is hampered by the absence of large studies with exposures and outcomes measured at different life stages in the same individuals. We describe when the effect of an exposure ( A ) on an outcome ( Y ) in a target population is identifiable in a combined ("synthetic") cohort created by pooling an early-life cohort including measures of A with a late-life cohort including measures of Y . We enumerate causal assumptions needed for unbiased effect estimation in the synthetic cohort and illustrate by simulating target populations under four causal models.

Associations of childhood, adolescence, and midlife cognitive function with DNA methylation age acceleration in midlife.

Prior studies showed increased age acceleration (AgeAccel) is associated with worse cognitive function among old adults. We examine the associations of childhood, adolescence and midlife cognition with AgeAccel based on DNA methylation (DNAm) in midlife. Data are from 359 participants who had cognition measured in childhood and adolescence in the Child Health and Development study, and had cognition, blood based DNAm measured during midlife in the Disparities study.

Propensity Scores in Health Disparities Research: The Example of Cognitive Aging and the Hispanic Paradox.

Background: Individuals of Mexican ancestry in the United States experience substantial socioeconomic disadvantages compared with non-Hispanic white individuals; however, some studies show these groups have similar dementia risk. Evaluating whether migration selection factors (e.g.

History of Low Hourly Wage and All-Cause Mortality Among Middle-aged Workers.

Importance: Earning a low wage is an increasingly recognized public health concern, yet little research exists on the long-term health consequences of sustained low-wage earning.

Objective: To examine the association of sustained low-wage earning and mortality in a sample of workers with hourly wage reported biennially during peak midlife earning years.

Design, Setting, And Participants: This longitudinal study included 4002 US participants, aged 50 years or older, from 2 subcohorts of the Health and Retirement Study (1992-2018) who worked for pay and reported earning hourly wages at 3 or more time points during a 12-year period during their midlife (1992-2004 or 1998-2010).

Association of Low Hourly Wages in Middle Age With Faster Memory Decline in Older Age: Evidence From the Health and Retirement Study.

Little research has investigated the long-term relationship between low wages and memory decline, despite the growing share of low-wage workers in the US labor market. Here, we examined whether cumulative exposure to low wages over 12 years in midlife is associated with memory decline in later life. Using 1992-2016 data from the Health and Retirement Study, we analyzed data from 2,879 individuals born in 1936-1941 using confounder-adjusted linear mixed-effects models.

Could maternal thyroid function during pregnancy affect daughters' age at menarche through child growth? A mediation analysis.

Early menarche is associated with adverse health outcomes during adolescence as well as breast and other reproductive cancers later in adulthood. However, the causes of early menarche and the pathways through which they operate are not fully understood. Though maternal thyroid function during pregnancy affects child growth, and rapid childhood growth is associated with a decreased age at menarche, the relationship between prenatal maternal thyroid function and daughters' age at menarche has not been examined.

Is the Way Forward to Step Back? Documenting the Frequency With Which Study Goals Are Misaligned With Study Methods and Interpretations in the Epidemiologic Literature.

In any research study, there is an underlying process that should begin with a clear articulation of the study's goal. The study's goal drives this process; it determines many study features, including the estimand of interest, the analytic approaches that can be used to estimate it, and which coefficients, if any, should be interpreted. Misalignment can occur in this process when analytic approaches and/or interpretations do not match the study's goal; misalignment is potentially more likely to arise when study goals are ambiguously framed.

Tracking of Obesity in Childhood into Adulthood: Effects on Body Mass Index and Fat Mass Index at Age 50.

Obesity is present in 17% of US youth, age 2-19 years, but the extent to which obesity in childhood is associated with higher BMI and fat mass in middle age is unclear. In this study, links between childhood body size and BMI and body composition at age ∼50 were assessed. Child Health and Development Studies participants, born between 1960 and 1963 in Alameda County, and still living in California, from whom anthropometric data were collected at age 5, 9-11, and/or 15-17 years were followed-up at age ∼50 for anthropometric outcomes (251 women; 249 men).

Who is in this study, anyway? Guidelines for a useful Table 1.

Objective: Epidemiologic and clinical research papers often describe the study sample in the first table. If well-executed, this "Table 1" can illuminate potential threats to internal and external validity. However, little guidance exists on best practices for designing a Table 1, especially for complex study designs and analyses.

Body mass index across the life course: emergence of race-by-sex disparities in early childhood.

Purpose: The purpose of this study was to assess when in the life-course race-by-sex disparities in body mass index (BMI) emerge.

Methods: Child Health and Development Studies participants, from whom height and weight data were collected at ages 5, 9-11, and 15-17 years, were followed up at the age of 50 years for anthropometric outcomes. Follow-up was completed for 605 subjects, 460 of whom were assessed for height and weight at the age of 50 years, had at least one available childhood BMI measure, and self-identified as either non-Hispanic black or non-Hispanic white.

Prepregnancy overweight and obesity are associated with impaired child neurodevelopment.

The authors examined the relationship of prepregnancy body mass index (BMI) and gestational weight gain (GWG) with child neurodevelopment. Mother-child dyads were a subgroup (n = 2,084) of the Child Health and Development Studies from the Oakland, California, area enrolled during pregnancy from 1959 to 1966 and followed at child age 9 years. Linear regression was used to examine associations between prepregnancy BMI, GWG, and standardized Peabody Picture Vocabulary Test and Raven Progressive Matrices scores and to evaluate effect modification of GWG by prepregnancy BMI.

Disparities in self-rated health across generations and through the life course.

Extensive evidence leads us to expect that health disparities by race and socioeconomic status found in one generation might be reproduced in the next. To the extent that this occurs it is important to assess life course processes responsible for the reproduction. Prospective evidence concerning such life course processes is hard to come by as it requires long-term follow-up of individuals from childhood through adult life.

Dichlorodiphenyltrichloroethane (DDT), DDT metabolites and pregnancy outcomes.

Organochlorine pesticides (OCPs) are persistent endocrine disruptors. OCPs cross the placenta; this prenatal exposure has been associated with adverse pregnancy outcomes. We investigated associations between prenatal exposure to OCPs and gestational age and birth weight in 600 infants born between 1960 and 1963.

Prenatal polychlorinated biphenyl exposure is associated with decreased gestational length but not birth weight: archived samples from the Child Health and Development Studies pregnancy cohort.

Background: Polychlorinated biphenyls (PCBs), known endocrine disruptors, were banned in 1979 but persist in the environment. Previous studies are inconsistent regarding prenatal exposure to PCBs and pregnancy outcomes. We investigated associations between prenatal exposure to PCBs and gestational length and birth weight.