On the age-period-cohort analysis of suicide rates

1988 ◽  
Vol 18 (3) ◽  
pp. 677-681 ◽  
Author(s):  
Stephen C. Newman ◽  
Ronald J. Dyck

SynopsisCohort analysis has become a popular method of examining national trends in suicide rates. Most of the studies investigating this phenomenon have reported a cohort effect to be present. Using a graphical approach, this paper places cohort analysis within the broader framework of age-period-cohort analysis. It is shown that published reports may have failed to identify cohort effects due to using only portions of the available data. With a simple mathematical model it is demonstrated that what appears to be a cohort effect may be a period effect, and conversely. It is recommended that suicide rates be examined for both period and cohort effects before conclusions are drawn regarding trends, and that the complete data set be used for this purpose.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nam-Hee Kim ◽  
Ichiro Kawachi

AbstractThere have been marked improvements in oral health in Korea during the past 10 years, including chewing ability. We sought to disentangle age, period, and cohort effects in chewing ability between 2007 and 2018. We analyzed data from the Korea National Health and Nutrition Examination Survey. The main variable was chewing difficulty, which was assessed among participants aged 20 years and older. APC analysis revealed three trends in chewing difficulty: (1) there was an increase in chewing difficulty starting at around 60 years of age (age effect), (2) there was a steady decrease in chewing difficulty during the observation period (period effect), and (3) chewing ability improved with each successive generation born after 1951 (cohort effect). Regarding recent improvements in chewing ability, cohort effects were somewhat more important than period effects.


2015 ◽  
Vol 42 (3-4) ◽  
pp. 1 ◽  
Author(s):  
Lise Thibodeau

Suicide rates raise with age has remained consistent for more than 150 years but over the last 50 years major changes occurred. We examined Age-Period-Cohort (APC) effects on suicide mortality rate by gender in Canada and in Quebec from 1926 to 2008. Durkheim theoretical framework is used to interpret our findings. Descriptive analysis and APC models relating to the Intrinsic Estimator (IE) were used to assess these effects. IE model shows suicide net age effect for men in Canada and Quebec as death rate increased until 25 years old before reaching a plateau. For women it’s an inverted "U" shape peaking at mid-adulthood. While period effect differs, a net cohort effect is found for men born in 1941, and women in 1981 until most recent cohorts. 


1991 ◽  
Vol 25 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Keren Skegg ◽  
Brian Cox

New Zealand suicide rates from 1957 to 1986 were analysed for age, period and cohort effects. Cumulative suicide rates were relatively stable but more complex patterns were revealed by detailed analysis. There was a steadily increasing rate in young men and a recent increase in elderly men. Reduced mortality rates in equivalent categories of accidental and “undetermined” deaths could have accounted for only a proportion of these increases. A cohort effect was noted in men, with increasing risks of suicide in the young for successive birth-cohorts born from 1947 onwards. In women a period effect was likely, with increasing rates for all age-groups between 1957–61 and 1962–66, followed by a decline recently among all except the youngest age-groups. These trends in women may have been largely due to changes in barbiturate prescribing. In both sexes poisoning declined as a method of suicide, while hanging and carbon monoxide poisoning increased. Firearm suicides also increased in men. The implications of these results for prevention are considered.


2021 ◽  
Author(s):  
Yufeng Wang ◽  
Xueying Huang ◽  
Huan Ma ◽  
Suru Yue ◽  
Jie Liu ◽  
...  

Abstract Background Migraine is a common disorder of the nervous system in China, imposing heavy burdens on individuals and societies. Optimal healthcare planning requires understanding the magnitude and changing trend of migraine incidence in China. However, the secular trend of migraine incidence in China remains unclear. Methods Data were collected from the Global Burden of Disease Study 2019 in China from 1990 to 2019 to investigate changes in the incidence rate of migraine. The average annual percent change and relative risk were calculated using joinpoint regression and an age–period–cohort model, respectively. Results From 1990 to 2019, the age-standardized incidence rates of migraine in China increased by 0.26% (95% CI: 0.22 to 0.31) and 0.23% (95% CI: 0.19 to 0.28) per year in males and females, respectively. The age effect exerted the most significant impact on the incidence of migraine. The period effect showed a slightly decreasing trend in the incidence of migraine. In terms of the cohort effect, people born after the 1960s presented a higher risk of migraine as compared with the total cohort, with the occurrence risk of migraine increasing with birth cohorts. Conclusion Migraine incidence shows an overall increasing trend in China, with a significant gender difference. An intensive understanding of the risk characteristics and disease pattern of migraine could allow the early detection of persons with a high risk of developing migraine and promote the development of timely intervention measures to relieve this burden effectively.


2021 ◽  
Vol 66 ◽  
Author(s):  
Hang-Hang Luan ◽  
Li-Sha Luo ◽  
Zhi-Yan Lu

Objectives: This study aimed to estimate the long-term trends of breast cancer incidence in Shanghai, Hong Kong, and Los Angeles (LA).Methods: Data were obtained from Cancer Incidence in Five Continents (CI5plus) database. The average annual percent change (AAPC) was conducted by joinpoint regression analysis, and the age, period and cohort effects were estimated by age-period-cohort (APC) analysis.Results: The age-standardized incidence rates (ASIRs) in LA were higher than Shanghai and Hong Kong. During 1988–2012, the ASIRs significantly decreased in white women in LA (AAPC = −0.6%, 95% CI: −0.9% to −0.4%) while increased in Shanghai (2.5%: 2.1%–2.9%) and Hong Kong (2.2%: 2.0%–2.5%). The APC analysis revealed significantly increased effects of age and period, and decreased effect of birth cohort.Conclusion: Although age and cohort effects were relatively strong, the period effect may be the key factor affecting trends of incidence, which may be caused by increasing exposures to carcinogens and risk factors. Therefore, more effective measures should be carried out promptly to protect high-risk populations such as elder women, to avoid exposures to risk factors of breast cancer.


Author(s):  
Chunhui Li ◽  
Songbo Hu ◽  
Chuanhua Yu

The aim was to study the variation trends of all-cause and cancer mortality during 1984–2013 in Macheng City, China. The mortality data were collected from Macheng City disease surveillance points system and Hubei Center for Disease Control and Prevention. The model life table system was used to adjust mortality rates due to an under-reporting problem. An age-period-cohort model and intrinsic estimator algorithm were used to estimate the age effect, period effect, and cohort effect of all-cause mortality and cancer mortality for males and females. Age effect of all-cause mortality for both sexes increased with age, while the age effect of cancer mortality for both sexes reached a peak at the age group of 55–59 years old and then decreased. The relative risks (RRs) of all-cause mortality for males and females declined with the period and decreased by 51.13% and 63.27% during the whole study period, respectively. Furthermore, the period effect of cancer mortality in both sexes decreased at first and then increased. The cohort effect of all-cause and cancer mortality for both sexes born after 1904 presented the pattern of “rise first and then fall,” and decreased by 82.18% and 90.77% from cohort 1904–1908 to 1989–1993, respectively; especially, the risk of all-cause and cancer mortality for both sexes born before 1949 was much higher than that for those born after 1949.


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
William Campbell ◽  
Jean Twenge ◽  
Nathan Carter

In three large, nationally representative surveys of U.S. 12th graders, college students, and adults (N = 9 million) conducted 1968–2015, Americans became significantly more supportive of legal marijuana (cannabis) starting in the mid-1980’s. Hierarchical models using age-period-cohort analysis on the adult (General Social Survey) sample showed that the increased support for legalization is primarily a time period effect rather than generational or age effect; thus, Americans of all ages became more supportive of legal marijuana. Among 12th graders, support for marijuana legalization was closely linked to perceptions of marijuana safety.


Author(s):  
Xiaoxue Liu ◽  
Chuanhua Yu ◽  
Yongbo Wang ◽  
Yongyi Bi ◽  
Yu Liu ◽  
...  

Background: The prevalence of diabetes mellitus is rapidly increasing in China, but the secular trends in incidence and mortality remain unknown. This study aims to examine time trends from 1990 to 2017 and the net age, period, and cohort effects on diabetes incidence and mortality. Methods: Incidence and mortality rates of diabetes (1990–2017) were collected for each 5-year age group (from 5–9 to 80–84 age group) stratified by gender from the Global Burden of Disease 2017 Study. The average annual percentage changes in incidence and mortality were analyzed by joinpoint regression analysis; the net age, period, and cohort effects on the incidence and mortality were estimated by age-period-cohort analysis. Results: The joinpoint regression analysis showed that age-standardized incidence significantly rose by 0.92% (95% CI: 0.6%, 1.3%) in men and 0.69% in women (95% CI: 0.3%, 1.0%) from 1990 to 2017; age-standardized mortality rates rose by 0.78% (95% CI: 0.6%, 1.0%) in men and decreased by 0.12% (95% CI: −0.4%, 0.1%) in women. For age-specific rates, incidence increased in most age groups, with exception of 30–34, 60–64, 65–69 and 70–74 age groups in men and 25–29, 30–34, 35–39 and 70–74 age groups in women; mortality in men decreased in the younger age groups (from 20–24 to 45–49 age group) while increased in the older age groups (from 50–54 to 80–84 age group), and mortality in women decreased for all age groups with exception of the age group 75–79 and 80–84. The age effect on incidence showed no obvious changes with advancing age while mortality significantly increased with advancing age; period effect showed that both incidence and mortality increased with advancing time period while the period trend on incidence began to decrease since 2007; cohort effect on incidence and mortality decreased from earlier birth cohorts to more recent birth cohorts while incidence showed no material changes from 1982–1986 to 2012–2016 birth cohort. Conclusions: Mortality decreased in younger age groups but increased in older age groups. Incidence increased in most age groups. The net age or period effect showed an unfavorable trend while the net cohort effect presented a favorable trend. Aging likely drives a continued increase in the mortality of diabetes. Timely population-level interventions aiming for obesity prevention, healthy diet and regular physical activity should be conducted, especially for men and earlier birth cohorts at high risk of diabetes.


2010 ◽  
Vol 26 (7) ◽  
pp. 1446-1456 ◽  
Author(s):  
Christiane Maria Meurer Alves ◽  
Ronaldo Rocha Bastos ◽  
Maximiliano Ribeiro Guerra

This study identifies the period and cohort effects on the decreasing mortality trend of cancer of the uterine cervix and of the uterus, part unspecified, in the state of Minas Gerais, Brazil, during the period 1980-2005. 11,243 cases were included. A non-parametric method was used to calculate Z statistics and p-values. The cohorts were assessed one by one and also in blocks of three, so as to allow for a larger number of comparisons to be made. Greater than expected mortality reduction was observed for the cohort blocks of women born in 1913-1920; 1927-1936; 1937-1946; 1949-1956; 1963-1970; and 1969-1976. For the 1901-1908 and 1921-1928 cohort blocks a smaller than expected mortality decrease was found. As for period effect, we found a greater than expected reduction for the 2000-2001 period, in comparison with the previous one. The study suggests the existence of a significant cohort effect on mortality due to cancer of the uterine cervix in the study population, and such results have been placed in their social and political contexts.


1989 ◽  
Vol 68 (12) ◽  
pp. 1777-1780 ◽  
Author(s):  
J.E. Frencken ◽  
M.A. Van't Hof ◽  
G.-J. Truin ◽  
B.S. Lembariti ◽  
K.G. König

In 1984, a four-year mixed-longitudinal study of oral health was begun in Morogoro Town and Morogoro District, Tanzania. Its main goal was to detect a possible upward trend in prevalence of caries in child cohorts in this developing country. The sample consisted of 722 seven-to nine-year-olds in 1984, 833 seven- to 11-year-olds in 1986, and 989 seven- to 13-year-olds in 1988. Mixed-longitudinal studies provide the opportunity for application of the Age-Period-Cohort analysis. On the basis of external information, either age and/or cohort and/or period effects can thus be isolated. Apart from significant age and period effects, a cohort effect was found, indicating that the prevalence of caries has decreased in these child populations between 1984 and 1988.


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