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Walking promotes active aging; however, walking prevalence changes among older adults by age and environmental conditions remain unclear. Age-period-cohort (APC) differences in walking trends among Korean older adults were examined. Data included adults aged ≥ 65 years (n = 592,235) from the nationally representative Korean Community Health Survey. Regional units examined were metropolitan cities, small- and medium-sized cities, and rural areas. Environment-stratified APC modeling was applied for walking prevalence (walking days/time during the past week). From 2008 to 2017, the walking prevalence gap between regional units widened. Decreasing trends were most apparent in rural areas, including by birth year. In all areas, walking decreased with increased age. No distinct period effects were found. Each effect’s magnitude was larger in rural areas than cities. Differential APC effects by environmental conditions likely influence walking prevalence changes among older adults. Walking promotion for older adults should consider APC effects and environmental conditions.

Introduction In the U.S., state-level household firearm ownership is strongly associated with firearm suicide mortality rates. Whether the recent increases in firearm suicide are explained by state-level household firearm ownership rates and trends remains unknown. Methods Mortality data from the U.S. National Vital Statistics System and an estimate of state-level household firearm ownership rate were used to conduct hierarchical age–period–cohort (random-effects) modeling of firearm suicide mortality between 2001 and 2016. Models were adjusted for individual-level race and sex and for state-level poverty rate, unemployment rate, median household income in U.S. dollars, population density, and elevation. Results Between 2001 and 2016, the crude national firearm suicide mortality rate increased from 6.8 to 8.0 per 100,000, and household firearm ownership rate remained relatively stable, at around 40%. Both variables were markedly heterogeneous and correlated at the state level. Age–period–cohort models revealed period effects (affecting people across ages) and cohort effects (affecting specific birth cohorts) underlying the recent increases in firearm suicide. Individuals born after 2000 had higher firearm suicide rates than most cohorts born before. A 2001–2006 decreasing period effect was followed, after 2009, by an increasing period effect that peaked in 2015. State-level household firearm ownership rates and trends did not explain cohort effects and only minimally explained period effects. Conclusions State-level firearm ownership rates largely explain the state-level differences in firearm suicide but only marginally explain recent increases in firearm suicide. Although firearms in the home increase firearm suicide risk, the recent national rise in firearm suicide might be the result of broader, more distal causes of suicide risk.

In a pattern called immune imprinting, individuals gain the strongest immune protection against the influenza strains encountered earliest in life. In many recent examples, differences in early infection history can explain birth year-associated differences in susceptibility (cohort effects). Susceptibility shapes strain fitness, but without a clear conceptual model linking host susceptibility to the identity and order of past infections, general conclusions on the evolutionary and epidemic implications of cohort effects are not possible. Failure to differentiate between cohort effects caused by differences in the set, rather than the order (path), of past infections is a current source of confusion. We review and refine hypotheses for path-dependent cohort effects, which include imprinting. We highlight strategies to measure their underlying causes and emergent consequences.

Objectives To analyze and compare the experience of climacteric symptoms and their associations with sociodemographic and health-related characteristics in two cohorts of Finnish women aged 52–56 years, born ten years apart and not now or previously on menopausal hormone therapy (MHT). Study design Nationwide population-based time-trend study with a large number of participants (n = 1986 + 1988). Main outcome measures The experience of climacteric symptoms was assessed by 12 commonly used menopause-related symptoms. Results Women aged 52–56 experienced more moderate or severe symptoms and fewer mild symptoms in 2010 than in 2000. Being unemployed or inactive was associated with more severe symptoms (P = 0.007), but employment status had no effect on the relative odds estimates. Conclusions The influence of the birth cohort and time-period effects as well as work-related factors on the experience of climacteric symptoms in women not now or previously on MHT needs further research, particularly since the change in the experience of symptoms found in this study occurred within only ten years.

Background The literature suggests depressive symptoms differ in a non-linear fashion across adulthood and are more commonly reported in women as compared to men. Whether these trends are observed across countries in population-based cohorts is unclear. Methods Cross-sectional observational study of approximately 138,000 women and men between the ages of 45 and 95 from three population-based cohorts representing Canadian, European, and American populations. Age, gender, educational attainment and annual income were assessed in each cohort. Depressive symptoms were assessed by the Center for Epidemiological Studies Depression Scale in the US and Canadian cohorts, and by the EURO-D in the European cohort. Results Across all three cohorts, non-linear age trends and gender differences were observed in the report of depressive symptoms, independent from educational attainment and annual income effects. The non-linear age trends reflected a negative association between depressive symptoms and age during midlife and then a positive association in late life. Females reported greater depressive symptoms than males; however, an interaction between gender and age was also observed in the Canadian and European cohorts. Among Canadians, the gender differences were largest after age 70, whereas among Europeans, gender differences where largest among those approximately aged 60. Limitations Limitations include: 1) the cross-sectional nature of the study, resulting in age differences potentially reflecting cohort effects rather than a developmental process; and 2) the use of different depressive symptoms measures across cohorts. Conclusions Characterization of depressive symptoms over mid and late adulthood in women and men provides insights into potential focal points for intervention and allocation of resources.

We use a stochastic age–period–cohort mortality model to analyse US data for years 1989–2015 and ages 50-75, separated by gender, educational attainment, and cause of death. The paper focuses, in particular, on the fitted cohort effect for each sub-population and cause of death with two key findings. First, causes of death with a strong or distinctively-shaped cohort effect are also causes of death with significant, controllable risk factors, and that the fitted cohort effect gives us insight into the underlying prevalence of specific risk factors (such as smoking prevalence). Second, although each sub-population and cause of death has its own distinctive model fit, there are sufficient similarities between cohort effects to allow us to postulate that there is a relatively small number of underlying controllable risk factors that drive these cohort effects. The analysis then gives us insight into the modelled cohort effect for all-cause mortality.

Background Worldwide, cervical cancer is the second-most-common malignancy of the female reproductive system. Due to its large population, China accounted for 11.9% of cervical cancer deaths, and 12.3% of global cervical cancer DALYs in 2017. In 2009, China launched a nationwide screening program, yet mortality from cervical cancer has shown an upward trend in recent years. The aim of this study was to explore factors affecting cervical cancer mortality rates in China, and contribute to their future reduction. Methods In this descriptive study, a Joinpoint regression analysis and age-period-cohort (APC) model based on the intrinsic estimator (IE) algorithm were utilized. Data from the period 1989–2018 were extracted from the International Agency for Research on Cancer (IARC) Database of WHO (1989–2000) and China Health Statistical Yearbook database (2002–2018). Results Our study found mortality from cervical cancer to have initially declined, but increase thereafter over the entire observation period in both rural and urban China. The influence of age, period and cohort effect on the mortality rate had statistical significance. The effect of age increased with years, becoming a contributing factor in women aged over 45 years countrywide. Conversely, the cohort effect became a protective factor for women born after 1938 in urban areas, and for women born after 1958 in rural areas. The period effect was relatively less impactful. Conclusions The study indicates that organized cervical screening projects facilitated the identification of potential patients, or patients with comorbidities. Correspondingly, mortality was found to increase with incidence, particularly among elderly women, indicating that newly diagnosed patients were at an advanced stage of cervical cancer, or were not receiving appropriate treatment. Therefore, the coverage of cervical cancer screening should be improved, and women’s health awareness promoted. Early diagnosis and treatment is critical to reduce the disease burden and improve outcomes.

Background Apparent associations between human papillomavirus (HPV) prevalence and age observed in cross-sectional studies could be misleading if cohort effects influence HPV detection. Methods Using data from 2003–2016 National Health and Nutrition Examination Surveys, we evaluated overall and 10-year birth cohort-specific cervicovaginal HPV prevalence estimates (any, high-risk [HR], and non-HR) by 3-year age group among 27 to 59-year-old women born in 1950–1979. Average percent changes (APC) in HPV prevalence by 3-year age were calculated. Results Overall, prevalence of any HPV declined from 49.9% in 27–29 year olds to 33.8% in 57–59 year olds (APC, −2.82% per 3-year age group; 95% confidence interval [CI], −4.02% to −1.60%) as did prevalence of HR-HPV (APC, −6.19%; 95% CI, −8.09% to −4.26%) and non–HR-HPV (APC, −2.00%; 95% CI, −3.48% to −.51%). By birth cohort, declines by age group were seen in prevalences of any HPV, HR-HPV, and non–HR-HPV for those born in the 1950s and 1970s and in any HPV and HR-HPV for those born in the 1960s (APC range, −14.08% to 0.06%). Conclusions Declines in HPV prevalence with age in these cross-sectional surveys cannot be explained by birth cohort differences alone, as associations were observed across all birth cohorts.

An increasing incidence of thyroid cancer has been seen in China during the past several decades. The aim of this study was to analyze potential age, period, and cohort effects on the incidence of thyroid cancer in mainland China and to predict new cases up to 2032. We calculated age-adjusted and age-specific incidence rates of thyroid cancer, conducted an age–period–cohort analysis of 35,037 thyroid cancer incidence cases reported to Cancer Incidence in Five Continents from 1983 to 2012 in mainland China, and predicted incidence up to 2032 using the Bayesian age–period–cohort method. The age-adjusted overall incidence rate of thyroid cancer increased from 1.93/100,000 in 1983–1987 to 12.18/100,000 in 2008–2012 among females and from 0.77/100,000 in 1983–1987 to 3.89/100,000 in 2008–2012 among males, with a female-to-male ratio of approximately 3.0 during the three decades. Strong birth cohort and period effects on the incidence of thyroid cancer were observed for both sexes, and such an increasing trend is predicted to continue for at least the next 20 years. More than 3.7 million new cases are projected in the 2028–2032 period. The increasing trend of thyroid cancer in mainland China will cause a great burden in the future. In addition to the potential impact of improvement in medical diagnostics, potential exposure to risk factors have played a role in the observed rising trend. Further population-based epidemiologic studies are required to identify risk factors to aid in thyroid cancer prevention and control.

Purpose Urolithiasis is one of the commonest disease of the urinary system. This study aimed to assess the long-term urolithiasis incidence trends in China between 1990 and 2019. Patients and Methods The incidence data of urolithiasis were extracted from Global Burden of Disease Study 2019, and an age-period-cohort framework was used to estimate the age, period, and cohort effects. Results We found that the net drift was -2.72% (95% CI: -2.84% to -2.60%) per year for men and -2.14% (95% CI: -2.24% to -2.05%) per year for women, and except men in age group 0-4, the local drift values were below 0 in all age groups (P

Background Dementia is one of the most critical challenges of our time. According to the Dementia Statistics Hub, only about 66 % of all UK residents with dementia were diagnosed in 2017–2018. Yet, there are reservations about the early diagnosis of dementia-related diseases. As a result, the UK National Screening Committee does not recommend systematic population screening of dementia, although case-finding strategies are still applied for high-risk groups. Methods This study added additional evidence of the effectiveness of the National Dementia Strategy and increased numbers of diagnosis of dementia on the younger cohorts of the older people, using the intrinsic estimator age-period-cohort (APC) models and the English Longitudinal Study of Ageing data. Results Age effects show that diagnosis increases in volume only among those aged 75 and above, suggesting that many of those aged below 75 might not be diagnosed in time. Period effects show that although there was an initial increase due to the new policy implementation, the trend stalled in later years, indicating that the increase might not have been even across the period when controlled for age and cohort. The study also shows that cohort effects indicate lower prevalence in younger cohorts controlled for age and period effects. Conclusions Although more research in diverse contexts is warranted, this study cautions against the abandonment of timely diagnosis, increased screening and case-finding, and shows some effectiveness of prevention strategies on the national level.

Objectives No previous study has analysed age-, period-, and cohort-related long-term trends in toothbrushing frequency among adults using a nationally representative data set. Our aim was to study age, period, and cohort effects on toothbrushing among 15- to 64-year-olds in Finland from 1978 to 2014. Methods Data were gathered by nationally representative random cross-sectional samples of 15- to 64-year-old Finns annually from 1978 to 2014, during which response rates decreased from 84% to 53%. The final pooled sample size was 119,665. An age-period-cohort model was used to separate the effects of age, period, and cohort on trends in men's and women's toothbrushing frequency. Results From 1978 to 2014, the proportion of respondents who brushed at least twice a day or once a day increased from 42% to 66% and from 83% to 95%, respectively. The proportion of respondents who brushed at least twice a day increased from 27% to 53% among men and from 60% to 75% among women. Increases in at least once-a-day toothbrushing were smaller in both sexes, and in women the increase was minimal over the study years. The increase in toothbrushing frequency occurred particularly among those older than 40 years of age. In men, toothbrushing frequency increased steadily cohort by cohort (cohort effect) and within a single cohort as men in the cohort got older (longitudinal age trend). Instead, in women the cohort effect and longitudinal age trend in toothbrushing were smaller at both frequency thresholds. Conclusions On the population level, favourable changes in toothbrushing habits occurred among adult Finns from 1978 to 2014, especially in men.

Statistical evidence on breast cancer (BC) burden related to health and lifestyle risk factors are valuable for health policy-making. This study aimed to compare the trends in BC mortality and disability adjusted life years (DALYs) attributable to various health and life style risk factors among different world’s regions according to sociodemographic index (SDI). We extracted the age-standardized and age-specific rate of mortality and DALYs of women BC during 1990–2017 using the comparative risk assessment framework of the 2017 global burden of disease (GBD) study. We performed hierarchical age-period-cohort analysis to estimate age- and time-related trends, and effect of interactions between different risk factors on BC risk. During 1990–2017, the age-standardized rate of mortality and DALYs of women BC was increasing in less developed and under developing regions. The risk factor alcohol use [RR 51.3(95%CI 17.6–149.7)] and smoking [5.9(2.0–17.3)] were significantly highly contributor to increased mortality risk in high SDI region. Whereas in the low-SDI region, the greater mortality risk was observed in alcohol use [6.9(2.4–17)] and high FPG [2.7(1.5–3.1)]-related deaths. The adjusting for individual age, period, and risk factor effects, the significant interaction effect between metabolic risk factors and older ages were observed in all SDI regions and globally as well. However, an increasing cohort effect of alcohol, high fasting plasma glucose (FPG) and smoking-related death, and DALYs was observed during 1960 to 1985 cohorts among low-SDI regions. The age-standardized rates of mortality and DALYs due to BC has been increasing in low-SDI region. Alcohol consumption, high body mass index (BMI), high FPG, and smoking are potential BC risk factors particularly in older ages that leading to adverse disease outcomes. Therefore, rapid aging and prevalence of these prospective risk factors may strengthen the increasing mortality and DALYs of BC in low-SDI region. Hence, preventive measure along with strict action against concerned BC risk factors should be taken to reduce the disease burden specifically among lower-SDI regions.

The objective of the current study is to examine the impact of religiosity (the predictor) on the projected BMI and the probability of obesity (the outcomes). Given that obesity is a prominent risk factor for an extensive series of health problems and higher mortality rates, this research might prove to be important for policymaking and intervention. The focus of this study is the health-related effects associated with differences between UO and secular (religiously non-observant) Jewish communities in Israel. The study is based on a panel dataset covering up to four measured points in time (2012–2016). Indeed, compared to the secular community, and in contrast to females, the projected probability of 21-year-old UO males suffering from obesity (BMI ≥ 30) rises significantly by 9.9% (from 6.98 to 16.88%). Research findings thus support the need to develop awareness concerning a healthier lifestyle, particularly among young UO adult males.

Monitoring survival in cancer is a common concern for patients, physicians, and public health researchers. The traditional cohort approach for monitoring cancer prognosis has a timeliness problem. In this paper, we propose a survivorship-period-cohort (SPC) model for examining the effects of survivorship, period, and year-of-diagnosis cohort on cancer prognosis and for predicting future trends in cancer survival. We used the developed SPC model to evaluate the relative survival (RS) of patients with liver cancer in Taiwan (diagnosed from 1997 to 2016) and to predict future trends in RS by imputing incomplete follow-up data for recently diagnosed patient cohorts. We used cross-validation to select the extrapolation method and bootstrapping to estimate the 95% confidence interval for RS. We found that 5-year cumulative RS increased for both men and women with liver cancer diagnosed after 2003. For patients diagnosed before 2010, the 5-year cumulative RS rate for men was lower than that for women; thereafter, the rates were better for men than for women. The SPC model can help elucidate the effects of survivorship, period, and year-of-diagnosis cohort effects on cancer prognosis. Moreover, the SPC model can be used to monitor cancer prognosis in real time and predict future trends; thus, we recommend its use.

The role of sex, race, and suicide method on recent increases in suicide mortality in the United States remains unclear. Estimating the age, period, and cohort effects underlying suicide mortality trends can provide important insights for the causal hypothesis generating process. We generated updated age-period-cohort effect estimates of recent suicide mortality rates in the US, examining the putative roles of sex, race, and method for suicide, using data from all death certificates in the US between 1999 and 2018. After designating deaths as attributable to suicide according to ICD-10 underlying cause of death codes X60-X84, Y87.0, and U03, we (i) used hexagonal grids to describe rates of suicide by age, period, and cohort visually and (ii) modeled sex-, race-, and suicide method-specific age, period, and cohort effects. We found that, while suicide mortality increased in the US between 1999 and 2018 across age, sex, race, and suicide method, there was substantial heterogeneity in age and cohort effects by method, sex, and race, with a first peak of suicide risk in youth, a second peak in older ages—specific to male firearm suicide, and increased rates among younger cohorts of non-White individuals. Our findings should prompt discussion regarding age-specific clinical firearm safety interventions, drivers of minoritized populations’ adverse early-life experiences, and racial differences in access to and quality of mental healthcare.

Aims To investigate secular trends in severe periodontitis incidence, prevalence and disability-adjusted life year (DALY) rates in China, India, Japan, South Korea and Thailand from 1990 to 2017. Materials and methods Data were obtained from the "Global Burden of Disease Study" 2017. The annual percentage change and average annual percentage change were calculated using Joinpoint regression analysis. The independent age, period and cohort effects were estimated by age-period-cohort analysis. Results From 1990 to 2017, the overall age-standardized incidence, prevalence and DALY rates increased in China, Japan and India, while decreasing in South Korea and Thailand. The highest incidence, prevalence and DALY rates were in India. By APC analysis, the age effect presented increase in 20-59 years in China, Japan and South Korea, 20-54 years in India and 20-64 years in Thailand; the period effect showed progressive increases in five countries, with the most significant increase shown in China; the cohort effect showed monotonic decreases with birth cohort in five countries. Conclusions Severe periodontitis poses a serious burden in Asian countries, especially China and India. We suggest raising people's awareness of periodontal health and providing professional interventions in these countries, especially for high-risk groups, such as younger people aged ≤65 years.

BackgroundThyroid cancer (TC) is the most common malignant disease of the endocrine system. Based on the previously published reports, the incidence of TC has been increasing in the past 25 years, and the reason for the increase is not yet clear. The present study aims to reveal the long-term trends and age–period–cohort effects for the incidence of TC in China and the U.S. from 1990 to 2017.MethodsWe examined the trends of TC incidence and the average annual percentage change (AAPC) of rate using the Joinpoint regression analysis in the two countries, for the different genders (men/women) in the Global Burden of Disease (GBD 2017). We further used an age-period-cohort model to analyze age-period-cohort effects on TC incidence.ResultsThe ASIR of China increased markedly with AAPC of 4.5% (95% confidence interval (CI): 4.0, 5.0%) and 1.8% (1.6, 2.0%) for men and women during 1990–2017. The ASIR of the U. S increased by 1.4% (1.0, 1.8%) and 1.3% (0.9, 1.7%) for men and women from 1990 to 2017.TC increased with the age and period. Aging was one of the most influential factors of TC in China. The age effect increased markedly in the U.S. compared with China. The period effect showed an increase in China while that tended to grow steadily during 1990–2017 in the U.S. The cohort effect peaked in 1963–1967 birth cohorts for men and women in China and declined consistently in the birth cohort in the U.S.ConclusionFrom 1990 to 2017, due to ionizing radiation and over-diagnosis, age-standardized TC incidence rates in both genders rose in China and the U.S. The standardized incidence rate of women is higher than that of men. It is necessary to provide women with reasonable prevention and protection measures for TC. We need to apply for health services and screening to reduce ionizing radiation.

Introduction The ageing of baby boomers is expected to confront addiction care with new challenges. This cohort had greater exposure to psychoactive substances in youth than earlier cohorts. In this study, we aimed to investigate whether Berlin addiction care is confronted with a sustained change in its clientele initiated by the baby boomers. Methods Using data from Berlin outpatient addiction care facilities, we contrasted type of primary substance use disorder and number of comorbid substance use disorders in baby boomers with an earlier and a later cohort. To isolate cohort effects, two‐level random intercept regression models were applied in the overlapping age groups of the baby boomer cohort with each of the other cohorts. Results Compared with the earlier cohort, alcohol use disorder lost importance whereas illicit substance use disorder gained importance in the baby boomers. Baby boomers presented a higher number of comorbid substance use disorders than the earlier cohort. Comparing baby boomers with the later cohort, these relationships pointed in the opposite direction. Discussion and Conclusions Outpatient addiction care faces a sustained change to more illicit and comorbid substance use disorders. With increasing life expectancy and the ageing of baby boomers marked by higher substance use than previous cohorts, older clients, who had been under‐represented in outpatient addiction care, will gain relevance. Hence, addiction care has to adapt its offers to appropriately meet the changing needs of its clientele.

Background. As the second most common gynecologic cancer worldwide, cervical cancer has led to morbidity and mortality in thousands of women. Our study is aimed at comparing the long-term trends of mortality rates for cervical cancer in three high-income countries—Canada, Korea, and Italy—and analyzing the detached effects of chronological age, time period, and birth cohort by age-period-cohort (APC) analysis. Methods. Joinpoint regression was used in this study, and the age-period-cohort model combined with the intrinsic estimator method was also applied to estimate the detached effect of each age, time period, and birth cohort on cervical cancer mortality. Results. For the overall trends of ASMRs for cervical cancer, the rates for Canada and Italy generally decreased during the whole observation periods while the rate for Korea exhibited a significant increase from 1986 to 2003. The APC analysis suggested that the cancer mortality risks consistently increased with age in the age groups including women aged 20 to 50 years in all areas. The period effect exhibited a general upward trend for both Korea and Italy, while a decreased trend was observed for Canada during the whole observation period. The mortality risk generally decreased with birth cohort, except there was a slight increase for younger generations in the three countries. Conclusions. Our study shows that the overall decrease in the cohort effect may have contributed to the reduced mortality rate for Italy and Canada, and the increased period effects and cohort effect in younger generations may have led to the increase in cancer mortality rate for Korea.

Relationships among somatic growth, climate, and fisheries production are poorly understood for coastal fishes in the Gulf of California (GoC), Mexico, but may serve as an adaptive management tool to set precautionary harvest limits for overfished, data-limited stocks. We explored linkages among the Multivariate ENSO Index (MEI), regional sea surface temperatures (SST), otolith growth chronologies of juveniles and adults, and annual landings in the Gulf corvina (Cynoscion othonopterus), an overexploited marine fish that supports the most important coastal finfish fishery in the northern GoC. Both MEI and SST were positively correlated with corvina landings five years later (peak age at capture), indicating that climate conditions at birth were a reliable predictor of future fisheries production. Juvenile growth rate covaried with both MEI and SST, confirming the influence of climate during early life history. There was no significant covariance from year to year in adult growth rate, but there was a significant cohort effect that positively correlated with MEI and SST, suggesting that climate conditions early in life exert lasting impacts that persist through adulthood. Differences in climate–growth relationships between juveniles versus adults were attributed to differences in the geographic distributions of the two life stages. Overall, we conclude that climate variability influences the future harvestable biomass of the corvina fishery via impacts on juvenile growth, and thus survivorship. Systematic monitoring of the corvina population, its fishery, and the biophysical components of the GoC environment must continue to improve our understanding of these climate-driven processes and the management of the fishery.

This paper elucidates that the AIDS/HIV incidence rate differences exist among different population and regions, especially among the old and college students. Due to the effect of age, the AIDS incidence peak in males aged 20–35 years and 50 years old both in Chongqing and Shenzhen, and the incidence rate and increasing spread in males was higher than that of females under period effect. In the local population in Chongqing and Shenzhen, the incidence rate of males in over 40, below and in the whole age groups are predicted to increase sharply in the future six years, while in females, the incidence rates among over 40-year-old and the whole age groups were predicted to increase as well. The incidence rate among homosexually transmitted patients reaches the peak in the 20–35, the incidence rate of patients transmitted through heterosexual reaches the peak around 50-year-old. Under the effect of period, AIDS/HIV incidence rate of patients transmitted through sexual routes showed an upward trend both in Chongqing and Shenzhen. The incidence rate of patients aged between 41 and 70 years old presents with an upward trend in the future six years. The results show great differences exist in the AIDS/HIV incidence between males and females, therefore it is necessary to take specific measures respectively.

Research has often found a U- or J-shaped association between parity and mortality. Many researchers have suggested repeated pregnancy, childbirth, and lactation taxes the body beyond a certain parity level. Available research has concentrated on populations with controlled fertility or historic populations. Ireland presents an opportunity to explore these associations in a modern sample with high fertility. We use data from the Irish Longitudinal Study on Ageing (TILDA) to test whether parity is associated with mortality in women aged 50 years or over (n = 4177). We use Cox proportional hazards models to model survival and adjust for demographics and early life circumstances. We test whether a number of health characteristics mediate these effects. Models were also stratified by birth cohort to test possible cohort effects. Higher parity was associated with lower risk of mortality, even after adjustment for early life and socioeconomic circumstances. This effect was not mediated by current health characteristics. The effects were largely driven by those born between 1931 and 1950. Increasing parity is associated with decreasing mortality risk in this sample. The effects of parity could not be explained through any of the observed health characteristics. These findings are in contrast to much of the literature on this question in similar populations. Lack of fertility control in Ireland may have “selected” healthier women into high parity. Social explanations for these associations should be further explored.

BACKGROUND Children belonging to the same birth cohort (i.e., born in the same year) experience shared exposure to a common obesity-related milieu during the critical early years of development-e.g., secular beliefs and feeding practices, adverse chemical exposures, food access and nutrition assistance policies-that set the stage for a shared trajectory of obesity as they mature. Fundamental cause theory suggests that inequitable distribution of recent efforts to stem the rise in child obesity may exacerbate cohort-based disparities over time. METHODS Data were from electronic health records spanning 2007-2016 linked to birth records for children ages 2-19 years. We used hierarchical age-period-cohort models to investigate cohort effects on disparities in obesity related to maternal education. We hypothesized that maternal education-based disparities in prevalence of obesity would be larger among more recent birth cohorts. RESULTS Sex-stratified models adjusted for race/ethnicity showed substantial obesity disparities by maternal education that were evident even at young ages: prevalence among children with maternal education

AimsTo analyse the independent effects of age, period and cohort on estimated daily alcohol consumption in Estonia.MethodsThis study used data from nationally representative repeated cross-sectional surveys from 1996 to 2018 and included 11,717 men and 16,513 women aged 16–64 years in total. The dependent variables were consumption of total alcohol and consumption by types of beverages (beer, wine and strong liquor) presented as average daily consumption in grams of absolute alcohol. Mixed-effects negative binomial models stratified by sex were used for age–period–cohort analysis.ResultsAlcohol consumption was highest at ages 20–29 years for both men and women and declined in older ages. Significant period effects were found indicating that total alcohol consumption and consumption of different types of beverages had increased significantly since the 1990s for both men and women. Cohort trends differed for men and women. Men born in the 1990–2000s had significantly lower daily consumption compared to earlier cohorts, whereas the opposite was found for women.ConclusionWhile age-related patterns of alcohol consumption are aligned with life course stages, alcohol use has increased over the study period. Although the total daily consumption among men is nearly four times higher than among women, the cohort trends suggest convergence of alcohol consumption patterns for men and women.

Objective To estimate Age-Period-Cohort effects on colorectal, colon and rectal cancer incidence rates in Latin American countries covered by high quality population-based cancer registries. Methods A trend study was performed using data from Cancer Incidence in Five Continents. Age-Period-Cohort effects were estimated by Poisson regression for individuals aged between 20 and 79 years with colorectal, colon and rectal cancers informed by Population-Based Cancer Registries from 1983 to 2012 in Cali (Colombia); from 1983 to 2007 in Costa Rica; and from 1988 to 2012 for both Goiânia (Brazil) and Quito (Ecuador). Goodness of fit model was tested using the deviance of the models. Results Age effect was statistically significant for both sexes in all Population-Based Cancer Registries areas and the curves slope reached peaks in the older age groups. There were cohort effects on the incidence rates for colorectal, colon and rectal cancers in all Population-Based Cancer Registries areas, except for women in Quito. Regarding the period effect, an increased ratio rate was observed in men (1.26, 95%CI 1.17 to 1.35) and women (1.23, 95%CI, 1.15 to 1.32) in Goiânia, between 2003 and 2007. Conclusions In Latin America, age effect was observed on incidence rates for colorectal, colon and rectal cancers. Besides, birth cohort effect was identified for recent cohorts in both genders for colorectal, colon and rectal cancers in Cali and Goiânia, and cohort effect for colorectal and colon cancers in both genders in Costa Rica; while in Quito a cohort effect was only observed for rectal cancer among men. Period effect was observed in Goiânia with increased ratio rate in 2003-2007. .

OBJECTIVES The purpose of this study was to identify the age, period and cohort effects on the changes in oral health status in South Koreans. METHODS The age, period and cohort analysis (APC analysis) of the oral health status was conducted using an aggregated age-by-time period table. The age-by-time period table was formulated using data from the Korea National Oral Health Survey (KNOHS) 2000 and 2006, and the Korea National Health and Nutrition Examination Survey (KNHANES) 2010 and 2015. Two oral health outcomes were measured: the number of teeth and Decayed-Missing-Filled Teeth (DMFT) index. Descriptive analysis by graphical representation and partial least square (PLS) regression was used for APC analysis. RESULTS Both graphical description and PLS regression showed age and cohort effects in oral health status with the number of teeth decreasing and the DMFT index increasing with age. No period effects were found in either index. The number of teeth increased in the recent birth cohorts. However, the DMFT index showed a reverse J-shaped trend, which worsened in recent birth cohorts. The DMFT index increase in the recent cohort was mainly attributed by an increase in the FT index. CONCLUSIONS The effects of age on the number of teeth and caries highlight the importance of oral health in adulthood. The increased caries experience in recent cohorts may indicate the limitations of the current oral health policy. It would be relevant to explore what determinants cause the changes in oral health status. Future oral health policies should address the new directions to reduce the burden of oral diseases.

This study involved an age-period-cohort analysis of the consultation rate and prevalence of dyslipidemia in Japan, based on Patient Survey data from 1999 to 2017 and open data of national database of health insurance claims and specific health checkups in Japan from 2013 to 2016. Our results showed that the consultation rates were lower than the prevalence, regardless of age, year, and sex, and particularly among middle-aged and male respondents. Additionally, both the consultation rate and prevalence increased with increasing age to a greater extent among women than men, and the degree of increase in the consultation rate was larger than that in prevalence among women. Furthermore, although the cohort effect on prevalence began to decrease among men in cohorts born in approximately 1960, the effect decreased among women in cohorts born between the 1930s and 1960s and exhibited an increasing trend thereafter.

Background Statistical data on the burden and relevant risk factors of lung cancer are valuable for policy‐making. This study aimed to compare the mortality of lung cancer attributable to smoking stratified by sex and age among adults in China and the United States (US). Methods We extracted age‐standardized mortality rates of lung cancer during 1990‐2017 using the comparative risk assessment framework of the 2017 Global Burden of Disease study. We performed an age‐period‐cohort analysis to estimate time trend of lung cancer mortality attributable to smoking. Results During 1990‐2017, the age‐standardized mortality rate of lung cancer was increasing in China but decreasing in the US for both sexes. The mortality attributable to smoking in China showed a generally increasing trend, while a continuous decrease was observed in the US. The age‐period‐cohort analysis showed a similar trend of age effect among adults between China and the US: the mortality substantially increased from the 30‐34 to 80‐84 age group and subsequently decreased in the 90‐94 age group. However, the period effect rapidly increased in Chinese adults during 1990‐2017, while it tended to be stable in the US although it was still slightly increasing in women. The cohort effect generally peaked in the earlier cohort born in 1902‐1906 in the two countries. Conclusions During 1990‐2017, the lung cancer mortality attributable to smoking and the period effect are generally increasing in Chinese adults; the mortality attributable to smoking is decreasing in the US adults, but the period effect tends to be stable. The rapid aging and prevalence of smoking may intensify the increasing mortality of lung cancer in China.

Background. This study aims at investigating differences in oral cancer (OC) incidence trends between two populations in Taiwan and Thailand. Methods. We used the population-based cancer registry data from Taiwan (1979-2016) and Khon Kaen (KK), Thailand (1985-2016). We performed joinpoint analyses to detect the trend change points for the OC incidence and to quantify the time trends in both sexes and regions. Age-period-cohort curves were plotted to explain the incidence trends. Results. In Taiwan, the estimated annual increases in OC were approximately 6.0% in males, although the increase slowed after 2009, and 2.6% in females. In KK, the OC incidence steadily decreased by -2.5% per year in females, but there was no obvious change in males. A strong period effect observed in those aged 45-69 years in Taiwanese males resulted in a peak incidence in the middle age group. Decreased period and cohort effects were observed in females in KK. Conclusions. Taiwanese males are the predominant sex affected by OC in Taiwan, and the trend has decelerated since 2009. Age, period, and cohort effects were different between males and females in the two regions.

We estimate the dementia incidence hazard in Germany for the birth cohorts 1900 until 1954 from a simple sample of Germany’s largest health insurance company. Followed from 2004 to 2012, 36,000 uncensored dementia incidences are observed and further 200,000 right-censored insurants included. From a multiplicative hazard model we find a positive and linear trend in the dementia hazard over the cohorts. The main focus of the study is on 11,000 left-censored persons who have already suffered from the disease in 2004. After including the left-censored observations, the slope of the trend declines markedly due to Simpson’s paradox, left-censored persons are imbalanced between the cohorts. When including left-censoring, the dementia hazard increases differently for different ages, we consider omitted covariates to be the reason. For the standard errors from large sample theory, left-censoring requires an adjustment to the conditional information matrix equality.

Background Emergency room (ER) physicians need to face clinically suspected pneumonia patients in the front line of medical care and must do to give major medical interventions if patients show severity in pneumonia. Methods The data of pneumonia-related ER visit rates were categorized based on the International Classification of Disease (ICD) Codes (480-486) between 1998 and 2012. We use an age-period-cohort (APC) model to separate the pneumonia-related ER visit rates to identify the effects of age, time period, and cohort for a total of 1,813,588 patients. Results The age effect showed high risk for pediatric and elder populations. There is a significant increasing period effect, which increased from 1998 to 2012. The cohort effect tended to show an oscillation from 1913 to 1988 and the reverse in a recent cohort. Furthermore, the visit rate of pneumonia showed an increase from 1998 to 2012 for both genders. Conclusion Age is a risk factor for pneumonia-related ER visits, especially for children and adolescents and older patients. Period and cohort effects were also found to increase the pneumonia visit rates. An APC model used to provide an advance clue for trend of pneumonia-related ER visit rates diversified.

The obesity epidemic represents an important public health issue in the United States. Studying obesity trends across age groups over time helps to identify crucial relationships between the disease and medical treatment allowing for the development of effective prevention policies. We aim to define subgroups of age and cohort effects in obesity prevalence over time by considering an optimization approach applied to the age-period-cohort (APC) model. We consider a heterogeneous regression problem where the regression coefficients are age dependent and belong to subgroups with unknown grouping information. Using the APC model, we apply the alternating direction method of multipliers (ADMM) algorithm to develop a two-step algorithm for (1) subgrouping of cohort effects based on similar characteristics and (2) subgrouping age effects over time. The proposed clustering approach is illustrated for the United States population, aged 18-79, during the period 1990-2017.

BackgroundEating disorders (ED) have increasingly become a global topic of concern for public health. A better understanding of ED incidence is a basic requirement for improving its management. However, the temporal trend of ED incidence in China is still unknown.MethodsThe incidence rates of ED from 1990 to 2017 were collected from the Global Burden of Disease Study 2017 database according to the following: subtype, i.e. anorexia nervosa (AN) and bulimia nervosa (BN); sex; and age group. The average annual percent changes and relative risks were calculated using joinpoint regression and the age–period–cohort model, respectively.ResultsFrom 1990 to 2017, age-standardized incidence rates of ED continued to increase in males and females, and this variation trend was observed in AN and BN. Joinpoint regression analysis showed that the incidence rates increased in all age groups. Adolescents had the highest risk of developing ED, followed by young adults. Age effects were the most influential risk factor for ED incidence. Period effects showed that the risk of developing ED continuously increased with increasing time periods in BN, but not in ED and AN. Concerning the cohort effects, people born after the 1990s presented a higher risk of ED, though they presented a lower risk of BN as compared to the whole cohort.ConclusionsED incidence rates continue to increase in China, particularly among adolescents and young adults. Further etiological studies are needed to explain these increases and to facilitate the early identification of high-risk individuals.

Background This study described the incidence and mortality trends and analyzed age-period-cohort effects on incidences in China, Japan, and Korea. Methods Data were extracted from the Cancer Incidence in Five Continents series and the World Health Organization Cancer Mortality Database, and the age-standardized incidence and mortality rates by Segi's world population were calculated. Joinpoint regression analysis was used to evaluate the time trend of age-standardized incidence and mortality rates and the age-period-cohort model with intrinsic estimator was applied for estimating the effects of age, period, and cohort on thyroid cancer (TC) incidence in individuals between 20 and 84 years of age. Results An increasing trend in TC incidence rates was observed among males from China (10.3%), Japan (4.7%), and Korea (20.8%) and among females from China (9.4%), Japan (3.5%), and Korea (20.5%). TC incidence rates in females were much higher than those in males. A downward trend of TC mortality rates was observed, especially in both sexes of Japan and Chinese females. The slope of the age effect curve peaked at an earlier age in females than males in Japan and Korea. A strong period effect and remarkedly increasing rate ratios were observed in all regions and for both sexes. The cohort effect had a declining tendency on TC incidence in males and females in these areas. Conclusions The rapidly upward incidence trend and strong period effect suggest that overdiagnosis caused by higher diagnostic intensity might be an explanation for the upward trend, and some environmental risk factor exposures are also not excluded. In addition, the discrepant trends of TC incidence and mortality reveal the need to identify the few high-risk patients who needed further treatment from those patients who may not need treatment.

This article uses random and fixed effects regressions with 743,788 observations from panels of East and West Germany, the UK, Australia, South Korea, Russia, Switzerland and the United States. It shows how the life satisfaction of men and especially fathers in these countries increases steeply with paid working hours. In contrast, the life satisfaction of childless women is less related to long working hours, while the life satisfaction of mothers hardly depends on working hours at all. In addition, women and especially mothers are more satisfied with life when their male partners work longer, while the life satisfaction of men hardly depend on their female partners’ work hours. These differences between men and women are starker where gender attitudes are more traditional. They cannot be explained through differences in income, occupations, partner characteristics, period or cohort effects. These results contradict role expansionist theory, which suggests that men and women profit similarly from moderate work hours; they support role conflict theory, which claims that men are most satisfied with longer and women with shorter work hours.

Background Uncontrolled studies have reported associations between later Parkinson's disease onset in women and a history of giving birth, with age at onset delayed by nearly 3 years per child. We tested this association in two independent data sets, but, as a control to test for nonbiological explanations, also included men with PD. Methods We analyzed valid cases from the Parkinson's Progressive Markers Initiative incident sample (145 women, 276 men) and a prevalent sample surveyed by the New Zealand Brain Research Institute (210 women, 394 men). Results The association was present in both women and men in the Parkinson's Progressive Markers Initiative study, and absent in both in the New Zealand Brain Research Institute study. This is consistent with generational differences common to men and women, which confound with age at onset in incident-dominant samples. Conclusions Despite being replicable in certain circumstances, associations between childbirth and later PD onset are an artifact of generational cohort differences. © 2020 International Parkinson and Movement Disorder Society.

Purpose China has a heavy cancer burden. We aimed to quantitatively estimate the secular trend of cancer mortality and incidence in China. Methods We extracted numbers, age-specific and age-standardized rates of 29 cancer groups (from 1990 to 2017) from the Global Burden of Disease (GBD) study in 2017. We estimated rates of major cancer types for annual percent change by Joinpoint regression, and for age, period, and cohort effect by an age-period-cohort model. Results In 2017, breast cancer had the highest incidence rate in females. Lung cancer had the highest mortality and incidence rates in males. Although the age-standardized incidence rate of prostate cancer ranked second highest in males, it increased by 112% from 1990 to 2017. Individuals aged over 50 years were at high risk of developing cancer, and the number of deaths at this age accounted for over 89% of all cancers in all age groups. When compared with the global average level, the age-standardized mortality and incidence rates of both liver and esophageal cancers were 2.1 times higher in China, and stomach, lung and nasopharyngeal cancers in China also had high levels (more than 1.5 times higher). During 1990-2017, most of the 29 cancers exhibited an increasing incidence trend, and Joinpoint regression demonstrated increasing mortality of some major cancers. The period effect indicated that the risk of mortality and incidence due to the main cancers generally increased during 1992-2017. Conclusion Trend analysis provided information on the effects of prevention strategies and targeted interventions on the occurrence of different cancers. Etiological studies need to be conducted on some major cancers in the Chinese population.

To analyse the age, period and cohort effects on the mean body mass index (BMI) and obesity over the past two decades in Estonia. Study used data from nationally representative repeated cross-sectional surveys on 11,547 men and 16,298 women from 1996 to 2018. The independent effects of age, period and cohort on predicted mean BMI and probability of obesity (BMI ≥ 30 kg/m2) were modelled using hierarchical age–period–cohort analysis. Curvilinear association between age and mean BMI was found for men, whereas the increase in mean BMI was almost linear for women. The predicted mean BMI for 40-year-old men had increased by 6% and probability of obesity by 1.8 times over 1996–2018; the period effects were slightly smaller for women. Men from the 1970s birth cohort had higher mean BMI compared to the average, whereas no significant cohort effects were found for obesity outcome. Population-level BMI changes in Estonia during 1996–2018 were mostly driven by period rather than cohort-specific changes.

Introduction: This study aimed to evaluate the reliability and validity of an Iranian computerized memory battery modeled after the Betula study. Methods: This study aimed to evaluate the reliability and validity of an Iranian computerized memory battery modeled after the Betula study (Nilsson et al., 1997). The researchers developed this battery as an assessment tool in the Sepidar prospective cohort study. One hundred and ninety-nine participants aged 19-83 years were tested extensively on different aspects of memory. Exploratory factor analysis of the data demonstrated factors similar to those reported by the Betula study. Results: The authors succeeded to converge the cross-sectional findings of the study and the data from longitudinal studies of memory aging by correcting possible cohort effects. Investigating age differences in episodic and semantic memory factor scores corrected by education and socioeconomic status revealed no significant difference between younger and older adults before ages 53 to 60, though linear age-related declines existed thereafter. Conclusion: The results support the reliability and construct validity of this computerized battery for memory assessment in Iranian adults., Originally article is written in Persian.