Achievements of the PERSIAN Birth Cohorts: A Systematic Review

This study identified recent changes in the prevalence of psychiatric disorders among Department of Veterans Affairs (VA) nursing home residents. Psychiatric diagnoses in administrative databases were summarized for nursing home residents in 1998, 2002, and 2006. Census prevalence rates were compared with findings from earlier VA nursing home surveys. Prevalence rates were compared for age groups and birth cohorts of VA nursing home admissions in 1998 (N=27,734) and 2006 (N=32,543). Among residents in the census samples, prevalence rates for dementia and schizophrenia fluctuated moderately from 1990 to 2006, depression prevalence increased sharply, alcohol use disorder prevalence declined, and drug use disorder prevalence increased. Among 1998 and 2006 admissions, dementia prevalence increased for most birth cohorts but declined for most age groups (35% to 32% overall). Depression prevalence increased for all age groups and birth cohorts (27% to 37% overall), as did posttraumatic stress disorder prevalence (5% to 12% overall). Serious mental illness prevalence increased among the oldest residents and birth cohorts (19% to 22% overall). Alcohol use disorder prevalence declined for all birth cohorts and most age groups (18% to 16% overall), but drug use disorder prevalence increased substantially for younger age groups (6% to 9% overall). Examining differences in prevalence between birth cohorts and age groups can clarify trends in nursing home resident characteristics and improve projections of their future needs.

Studies of couple fertility over time have often examined study populations with broad age ranges at a cross-section of time. An increase in fertility has been observed in studies that followed episodes of fertility events either prospectively among nulliparous women or retrospectively among parous women. Fertility has a biological effect on parity. If defined at a cross-section of time, parity will also be affected by year of birth, and thus becomes a collider. Conditioning (stratifying, restricting, or adjusting) on a collider may cause selection bias in the studied association. A study with prospective follow-up was taken as the model to assess the validity of fertility studies. We demonstrate the potential for selection bias using causal graphs and nationwide birth statistics and other demographic data. We tested the existence of parity-conditioning bias in data including both parous and nulliparous women. We also used a simulation approach to assess the strength of the bias in populations with prior at-risk cycles. Finally, we evaluated the potential for selection bias due to conditioning on parity in various sampling frames. Analyses indicate that the observed increase in fertility over time can be entirely explained by selection bias due to parity-conditioning. Heterogeneity in fertility and differential success in prior at-risk cycles are the ultimate factors behind the selection bias. The potential for selection bias due to parity-conditioning varies by sampling frame. A prospective multidecade study with representative sampling of birth cohorts and follow-up from menarche to menopause would bypass the described bias.

This study aimed to provide an autism spectrum disorder (ASD) prevalence update from parent and teacher report using the Longitudinal Study of Australian Children (LSAC). The LSAC is a prospective cohort study of Australian children representative of the population with two cohorts: Kinder (birth year 1999/2000) and Birth cohort (birth year 2003/2004). Children in the Birth and Kinder cohort with parent- and teacher-reported ASD prevalence were compared to children without ASD. There were N = 3,381 (66%) responding in the Birth cohort at age 12 and N = 3,089 (62%) for the Kinder cohort at age 16. Quality of life was measured by the Pediatric Quality of Life Inventory, and emotional/behavior problems using the Strengths and Difficulties Questionnaire. Parent-reported ASD prevalence increased to 4.36% [95% CI 3.56-5.19] at age 12-13 years in the Birth cohort and 2.60% [95% CI 2.07-3.31] in the Kinder cohort. Kinder cohort ASD children had more parent- and teacher-reported social problems, and lower parent-reported social and psychosocial quality of life. As expected, parent-reported ASD prevalence continued to rise. The higher prevalence in the Birth cohort may relate to milder cases of ASD being diagnosed. Autism Res 2020, 13: 821-827. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Parent-reported ASD prevalence in 2016 in 12-year-old children from the Birth cohort of the Longitudinal Study of Australian Children was 4.4%, and higher than the 2.6% in the earlier born Kinder cohort. The Birth cohort had a milder presentation with fewer social, emotional, and behavioral problems than the Kinder cohort. Milder cases of ASD are being diagnosed in Australia resulting in one of the highest reported prevalence rates in the world.

Evaluation of sexual behaviors is essential to better understand the epidemiology of sexually transmitted infections and their sequelae. The National Health and Nutrition Examination Surveys (NHANES) is an ongoing probability sample survey of the US population. Using NHANES sexual behavior data from 1999 to 2012, we performed the following: (1) trend analyses among adults aged 25 to 59 years by 10-year birth cohorts and (2) descriptive analyses among participants aged 14 to 24 years. Sex was defined as vaginal, anal, or oral sex. Among adults aged 25 to 59 years, median age at sexual initiation decreased between the 1940-1949 and 1980-1989 cohorts from 17.9 to 16.2 among females (P trend < 0.001) and from 17.1 to 16.1 among males (P trend < 0.001). Median lifetime partners increased between the 1940-1949 and 1970-1979 cohorts, from 2.6 to 5.3 among females (P trend < 0.001) and from 6.7 to 8.8 among males (P trend < 0.001). The percentage of females reporting ever having a same-sex partner increased from 5.2% to 9.3% between the 1940-1949 and 1970-1979 cohorts (P trend < 0.001). Among participants aged 14 to 24 years, the percentage having had sex increased with age, from 12.5% among females and 13.1% among males at age 14 years to more than 75% at age 19 years for both sexes. Among sexually experienced 14- to 19-year-olds, 45.2% of females and 55.0% of males had at least 3 lifetime partners; 39.4% of females and 48.6% of males had at least 2 partners in the past year. The proportion of females aged 20 to 24 years who reported ever having a same-sex partner was 14.9%. The proportion of participants aged 14-19 or 20-24 years reporting ever having sex did not differ by survey year from 1999 to 2012 for either males or females. Sexual behaviors changed with successive birth cohorts, with more pronounced changes among females. A substantial proportion of adolescents are sexually active and have multiple partners. These data reinforce existing recommendations for sexual health education and sexually transmitted infection prevention targeting adolescents before sexual debut.

To the Editor: The Centers for Disease Control and Prevention and US Preventive Services Task Force recommend a one-time screening for hepatitis C virus (HCV) infection in adults born during 1945–1965 (birth cohort), a demographic group with a disproportionately high prevalence of HCV infection (1,2). However, some experts have warned against routine HCV screening of persons in the birth cohort, stating that this recommendation is based on unproven assumptions about the benefit of screening in reducing HCV-related mortality, given that only a minority of infected persons develop end-stage liver disease (ESLD) (3). To determine the relative effect of the birth cohort on HCV-related ESLD incidence in the United States, we analyzed trends in liver transplantation (LT) waitlist registrations and LT surgeries during 1995–2012. Using data from the United Network for Organ Sharing national registry, we evaluated birth cohort–specific (birth cohort vs. non–birth cohort) and etiology-specific (HCV vs. non-HCV) trends in LT waitlist registrations and LT surgeries performed in the United States during that 18-year period. The proportion of HCV-infected persons born during 1945–1965 among all persons with LT waitlist registrations in the United States increased from 17.8% in 1995 to 35.2% in 2012 (Table). The highest proportion of LT waitlist registrations for HCV-related ESLD was for persons in the birth cohort and increased incrementally from 61.2% in 1995 to 90.5% in 2012. The proportion of LT waitlist registrations for HCV-related ESLD among persons younger than the birth cohort was 1.0% in 1995 and 3.6% in 2012; among persons older than the birth cohort, the proportion was 37.8% in 1995 and 5.9% in 2012. Table Liver transplant waitlist additions and liver transplant recipients, United States* Similarly, among LT recipients, the proportion of HCV-infected persons born during 1945–1965 doubled from 17.4% in 1995 to 35.4% in 2012 (Table). The proportion of LT surgeries performed for HCV-related ESLD among persons in the birth cohort increased from 60.2% in 1995 to 90.7% in 2012. Among persons younger than the birth cohort, the proportion of LT surgeries performed for HCV-related ESLD was 0.7% in 1995 and 5.0% in 2012; among persons older than the birth cohort, the proportion was 39.1% in 1995 and 4.3% in 2012. During 1995–2012, the ratio of new LT waitlist registrations to LT surgeries performed for HCV-infected persons in the birth cohort remained unchanged at 1.9:2.0 despite the aging of this birth cohort. Overall trends in HCV-related LT waitlist registrations and LT surgeries stabilized during 2001–2012; the proportion of HCV-infected persons in the birth cohort increased, and the proportion of HCV-infected persons not in the birth cohort decreased. To exclude the possibility that HCV-related ESLD has always simply affected persons 50–70 years of age, we performed a subanalysis examining the proportion of LT waitlist registrations and LT surgeries for persons 50–70 years of age in each year from 1995 through 2012. During this 18-year period, among persons 50–70 years of age, new HCV-related LT waitlist registrations increased from 43.9% to 93.0%, and LT surgeries performed increased from 47.1% to 86.2%. This finding suggests that persons born during 1945–1965 are a distinct birth cohort that is increasingly affected by HCV-related ESLD. Although persons born during 1945–1965 make up an estimated 27% of the US population, they account for ≈75% of all HCV infections and 73% of HCV-associated deaths in the United (1). Our findings are consistent with those of an earlier modeling study by Davis et al. (4), which suggested that the age of persons with HCV-related cirrhosis and its complications will continue to increase. Limitations of our study include inherent limitations of retrospective design and registry data. The designation of HCV infection and birth cohort status is based entirely on data entered into the database, which are not necessarily subject to cross-checking confirmatory measures. However, any errors in data entry that may have occurred are probably nondifferential. Despite these limitations, our analysis demonstrates that >90% of HCV-infected persons registered for LT or undergoing LT surgeries in 2012 were in the birth cohort. Earlier diagnosis and preemptive cure of HCV infection with highly effective and safe direct-acting antiviral drugs may delay or reduce the need for LT among persons in the birth cohort (5). Testing and linkage to care for HCV-infected persons, particularly persons in the birth cohort, can be expected to reduce HCV-related illness and death (1,2). In response to the approval of higher efficacy antiviral drugs and rapidly rising liver failure–related death among this cohort (6,7), the use of HCV-infected donors has increased, resulting in truncated wait times for HCV-infected LT recipients in many regions (8), whereas HCV-uninfected persons are generally waiting considerably longer, often years, for HCV-uninfected donors (9). This phenomenon is another index of the extent of HCV-related ESLD in the United States.

Time Trends of Ulcer Mortality in Europe

This study aims to test whether recent increases in the reported prevalence of opioid-use disorder in the United States occurred across all age groups (period effect), consistently only among younger age groups (age effect), or varied according to year of birth (cohort effects). Joint analysis of data from the 1991-1992 National Longitudinal Alcohol Epidemiologic Survey (NLAES) and the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), focusing on individuals ages 18-57, grouped by 10-year age intervals. Sample sizes for the present analyses were 30,846 for the NLAES and 31,397 for the NESARC. Prevalence of lifetime and past-year prescription opioid-use disorder resulting from nonmedical use (abuse and dependence) was examined. Within birth cohorts, prevalence of lifetime prescription opioid-use disorder increased during the 10 years between surveys, indicating the importance of age effects. In addition, lifetime and past-year prevalence of prescription opioid-use disorder was higher among more recent birth cohorts as compared with earlier birth cohorts, indicating the importance of cohort effects. Consistent with a period effect, cross-cohort comparisons showed that risk for prescription opioid-use disorder has increased for all individuals regardless of their birth cohort membership from the NLAES to the NESARC survey. Findings suggest that more problems (abuse and dependence) may emerge as prescription opioid users get older and that more recent birth cohorts are at higher risk for prescription opioid problems.

An Age-Period-Cohort Analysis of Cardiovascular Disease Mortality in the United States from 1999 to 2018

Age-period-cohort Analysis of Renal Cell Carcinoma in United States Adults

Age at marriage is rising throughout sub-Saharan Africa. The singulate mean age at marriage is now greater than 18 in the vast majority of countries in the region and in all of the countries included in our analysis (United Nations Department of Economic and Social Affairs Population Division 2015). Even so sub-Saharan Africa has the highest rates of child marriage in the world and previous studies have estimated that more than half of girls marry before age 18 in many countries in the region (Singh and Samara 1996; Mensch Singh and Casterline 2006). Measuring trends in the prevalence of child marriage over time is important for understanding where the practice is most common and for evaluating the effectiveness of efforts to eliminate it. However measuring age at marriage in sub-Saharan Africa is difficult. Unlike Western marriages which are often unambiguously dated by a ceremony the signing of legal documents and civil registration marriage in sub-Saharan Africa is often described as a process consisting of multiple stages including legitimized sexual relations cohabitation and ceremonies. The process can be lengthy and the various stages occur in different sequences across ethnic and social groups (van de Walle and Meekers 1994; Locoh 1994; Arnaldo 2004). If several events are required to solidify a union it may be unclear when the union was formalized. (excerpt)

Background: There is limited information on how polygenic scores (PSs) — based on variants from genome-wide association studies (GWAS) of T2D — add to clinical variables in predicting T2D incidence. Methods: For participants in a longitudinal study in an Indigenous population from the Southwest United States (US) with high T2D prevalence, we analyzed 10 constructions of PS using publicly available GWAS summary statistics. T2D incidence was examined in three cohorts of individuals without T2D at baseline. The adult cohort, comprised of 2333 participants followed from age≥20y, had 640 T2D cases. The youth cohort was comprised of 2229 participants followed from age 5-19y (228 cases). The birth cohort was comprised of 2894 participants followed from birth (438 cases). We assessed contributions of the PS and clinical variables in predicting T2D incidence. Results: Of the 10 PS constructions, a PS using 293 genome-wide significant variants from a large T2D GWAS meta-analysis in European-ancestry populations performed best. In the adult cohort, area under the receiver operating characteristic curve (AUC) for clinical variables for prediction of T2D incidence was 0·728; with the PS, 0·735. The PS’s hazard ratio (HR) was 1.27 per SD (p=1·6×10-8; 95% CI 1·17-1·38). In the youth cohort, the analogous model’s AUC was 0·805; with the PS, 0·812. The PS’s HR was 1·49 (p=4·3×10-8; 95% CI 1·29-1·72). In the birth cohort, AUC for the clinical variables was 0·614; with the PS, 0·685. The PS’s HR was 1·48 (p=2·8×10-16; 95% CI 1·35-1·63). To further assess the potential impact of including PS for assessing individual T2D risk, the net reclassification improvement (NRI) was calculated: NRI for the PS was 0·264, 0·249, and 0·309 for adult, youth, and birth cohorts, respectively. For comparison, NRI for HbA1c was 0·292 and 0·150 for adult and youth cohorts, respectively. Across all cohorts, as estimated using decision curve analyses, the net benefit of including the PS in addition to clinical variables was most pronounced at moderately stringent threshold probability (pt) values for instituting a preventive intervention. Discussion: This study demonstrates that the PS contributes significantly to prediction of T2D incidence in addition to the information provided by clinical factors; however, overall improvement of the prediction model was modest. Discriminatory power of the PS for predicting incident T2D was similar to that of other commonly measured clinical factors (e.g. HbA1c). Including T2D PS in addition to clinical factors may be clinically beneficial for identifying individuals at higher risk for T2D, especially at younger ages. Funding Statement: This study used computational resources of the Biowulf system at the National Institutes of Health (NIH), Bethesda, MD. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Intramural Research Program provided support for NIDDK-based coauthors. The NIH Oxford-Cambridge Scholars Program provided funding support for L.E.W.’s doctoral programme. M.I.M. was a Wellcome Senior Investigator and an NIHR Senior Investigator. This work was funded in Oxford by the Wellcome Trust (098381, 106130, 203141), NIH (U01- DK105535; U01-DK085545) and National Institute for Health Research (NIHR) (NF-SI-0617- 10090) and Oxford Biomedical Research Centre (BRC). Declaration of Interests: The views expressed in this article are those of the author(s) and not necessarily those of NIH, NHS, NIHR, or UK Department of Health. M.I.M. has served on advisory panels for Pfizer, Novo Nordisk, and Zoe Global; has received honoraria from Merck, Pfizer, Novo Nordisk, and Eli Lilly; and research funding from Abbvie, Astra Zeneca, Boehringer Ingelheim, Eli Lilly, Janssen, Merck, NovoNordisk, Pfizer, Roche, Sanofi Aventis, Servier, and Takeda. As of June 2019, M.I.M. and A.M. are employees of Genentech and holders of Roche stock. Ethics Approval Statement: Protocols were approved by the institutional review board of the National Institute of Diabetes and Digestive and Kidney Diseases.

Gilt progeny (GP) often have restricted growth performance and health status in comparison to sow progeny (SP) from birth, with the underlying mechanisms responsible for this yet to be fully understood. The present study aimed to compare differences in growth and development between GP and SP in the first 24 h after birth and in the periweaning period. Two cohorts of pigs including 36 GP and 37 SP were euthanized at 1 of 4 time points: a birth cohort (at birth before suckling, 0 h; and 24 h after birth, 24 h; n = 33) and a weaning cohort (at approximately 29 d of age; "pre-weaning," PrW; and 24 h after weaning; "post-weaning," PoW; n = 40). Pigs were individually weighed at 0 h, 24 h, PrW, and PoW up until the point of euthanasia, at which time the weights of selected tissues and organs were recorded and analyzed relative to BW. The length of the small intestine (SI), femur, and body were also measured, and a serum sample was collected and analyzed for IgG concentration. Samples of jejunal and ileal mucosa were collected and analyzed for total protein and specific activity of lactase. Euthanized GP were lighter (P < 0.01) than SP at all time points. At all time points, the ratios of quadriceps weight to femur length, BW to body length, spleen to BW (all P < 0.05), and SI weight to length (P < 0.10) were lower in GP than in SP. There was no difference (P ≥ 0.05) in stomach or heart to BW ratios between GP and SP in either cohort. The brain to liver weight ratio was greater (P = 0.044) in GP than in SP in the birth cohort, and the brain to BW ratio was greater (P < 0.01) in GP in both the birth and weaning cohorts. The liver to BW ratio was similar (P = 0.35) at birth but greater (P = 0.014) in GP around weaning. Total mucosal protein content in the jejunum and ileum was lower (P = 0.007) in GP at 24 h compared with SP, and specific activity of lactase was greater (P = 0.022) in GP in the birth cohort, whereas there were no differences in the weaning cohort (P ≥ 0.10). Gilt progeny had lower (P < 0.001) serum IgG concentration compared with SP at 24 h, but there was no difference (P ≥ 0.10) in the weaning cohort. Collectively, these findings suggest that the early development of GP may be delayed compared with SP and that a number of the anatomical differences between GP and SP that exist after birth are also present at weaning.

Preschool wheeze phenotypes from birth cohorts: Where do we go from here?

This study was to examine the time trend of the incidence rates of esophageal cancer during the period 1979-2003 in Hong Kong and to identify the effects of year of diagnosis (period) and year of birth (cohort) on the observed time trends using regression models. Cancer incidence data were obtained from Hong Kong Cancer Registry and population data were from the Census and Statistics Department. Age-standardized incidence rates were computed by the direct method using the World population of 1966. Annual percentage change (APC) in incidence rate was calculated using nonlinear regression. Period and cohort effects were assessed using 2 separate Poisson regression models after adjusting for age. During the period 1979-2003, a steady decrease in the age-standardized incidence rate was observed for both males (APC = -3.38%, 95% confidence interval [CI]: -2.89%, -3.86%) and females (APC = -3.92%, 95% CI: -3.15%, -4.69%). The incidence rates were consistently higher among males than females. After the adjustment for age and with the period 1989-1993 or birth cohort of 1934-1938 as reference, the relative risk of more recent periods or birth cohorts significantly decreased. The age-cohort model provided a better description of the data than the age-period model. Given reasonable latency between exposures and esophageal cancer incidence, the declining birth cohort effects in the recent generations were in line with the increased intakes of fresh vegetables and decreased consumptions of alcohol drinking, tobacco smoking, and preserved foods observed in population, thus supported their importance in influencing the burden of esophageal cancer.

Using the Past to Understand the Future of U.S. and Global Smoking Disparities: A Birth Cohort Perspective