Cohort Trends in Youth Suicide in Australia 1964–1997

2000 ◽  
Vol 34 (3) ◽  
pp. 408-412
Author(s):  
Michael Lynskey ◽  
Louisa Degenhardt ◽  
Wayne Hall

Objective: This paper examines trends in the rate of suicide among young Australians aged 15–24 years from 1964 to 1997 and presents an age-period-cohort analysis of these trends. Method: Study design consisted of an age-period-cohort analysis of suicide mortality in Australian youth aged between 15 and 24 for the years 1964–1997 inclusive. Data sources were Australian Bureau of Statistics data on: numbers of deaths due to suicide by gender and age at death; and population at risk in each of eight birth cohorts (1940–1944, 1945–1949, 1950–1954, 1955–1959, 1960–1964, 1965–1969, 1970–1974, and 1975–1979). Main outcome measures were population rates of deaths among males and females in each birth cohort attributed to suicide in each year 1964–1997. Results: The rate of suicide deaths among Australian males aged 15–24 years increased from 8.7 per 100 000 in 1964 to 30.9 per 100 000 in 1997, with the rate among females changing little over the period, from 5.2 per 100 000 in 1964 to 7.1 per 100 000 in 1997. While the rate of deaths attributed to suicide increased over the birth cohorts, analyses revealed that these increases were largely due to period effects, with suicide twice as likely among those aged 15–24 years in 1985–1997 than between 1964 and 1969. Conclusions: The rate of youth suicide in Australia has increased since 1964, particularly among males. This increase can largely be attributed to period effects rather than to a cohort effect and has been paralleled by an increased rate of youth suicides internationally and by an increase in other psychosocial problems including psychiatric illness, criminal offending and substance use disorders.

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jinhua Lu ◽  
Dongmei Wei ◽  
Songying Shen ◽  
Xiaoyan Xia ◽  
Jianrong He ◽  
...  

Abstract Background The incidence of preterm birth (PTB, < 37 weeks of gestation) has been increasing in China and many other countries in recent years. However, the causes of the increase were not well understood. The current study aims to examine the contribution of maternal age, period of delivery, and maternal birth cohorts to long-term trends in preterm birth in Guangzhou, China. Methods In a retrospective population-based study, data were obtained from 2,535,000 singleton live births with 20–43 gestational weeks from 2001 to 2016 and recorded in the Guangzhou Perinatal Health Care and Delivery Surveillance System, in China. The age-period-cohort models were applied to investigate the temporal changes in incidences of PTB, stratified by parity. Results The incidence of preterm birth steadily increased from 5.1% in 2001 to 5.9% in 2016, with larger rise in primiparous mothers (from 5.0 to 5.9%) compared to multiparous mothers (from 5.6 to 5.9%). A J-shaped and a V-shaped relationship were found between maternal age and PTB among primiparous and multiparous mothers, respectively. A linear cohort effect was found among primiparous mothers with the lowest risk of PTB [risk ratio (RR) = 0.81, 95% confidence interval (CI): 0.74 to 0.89] in 1961 and the highest risk (RR = 1.06, 95% CI: 1.00 to 1.13) in 1997 compared to the mothers born in 1981. An inverse U-shaped association between maternal birth cohort and PTB was found in multiparous mothers. There were weak decreasing period effects on the trend of overall PTB among multiparous mothers and on the trend of extremely (< 27 weeks) or very (28–31 weeks) PTB among both parity groups during the period of 2001–2012. Conclusions Our findings showed the PTB incidences had been increasing in the past 16 years in Guangzhou, China and both maternal age and cohort effects contributed to these trends. Further studies are recommended on the impact of altered maternal age and parity on premature births and corresponding public education and public health policies.


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.


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.


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.


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. 


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.


Author(s):  
Soonjoo Park ◽  
Yeong-Jun Song ◽  
Jinseob Kim ◽  
Myung Ki ◽  
Ji-Yeon Shin ◽  
...  

Although the effects of age, period, and cohort (APC) on suicide are important, previous work in this area may have been invalid because of an identification problem. We analyzed these effects under three different scenarios to identify vulnerable groups and thus overcame the identification problem. We extracted the annual numbers of suicides from the National Death Register of Korea (1992–2015) and estimated the APC effects. The annual average suicide rates in 1992–2015 were 31.5 and 14.7 per 100,000 males and females, respectively. The APC effects on suicide were similar in both sexes. The age effect was clearly higher in older subjects, in contrast to the minimal changes apparent during earlier adulthood. The birth cohort effect showed an inverted U shape; a higher cohort effect was evident in females born in the early 1980s when period drift was larger than 3.7%/year. Period effect increased sharply during the early 1990s and 2000s. We found that elderly and young females may be at a particularly high risk of suicide in Korea.


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.


2020 ◽  
pp. 1-11 ◽  
Author(s):  
Jiayuan Wu ◽  
Zhixiong Lin ◽  
Zhou Liu ◽  
Hairong He ◽  
Ling Bai ◽  
...  

Abstract Background Eating 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. Methods The 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. Results From 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. Conclusions ED 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.


Crime Science ◽  
2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Anthony Dixon ◽  
Graham Farrell

AbstractAdopting and refining O’Brien’s S-constraint approach, we estimate age-period-cohort effects for motor vehicle theft offences in the United States for over half a century from 1960. Taking the well-established late-teen peak offending age as given, we find period effects reducing theft in the 1970 s, and period, but particularly cohort effects, reducing crime from the 1990s onwards. We interpret these effects as consistent with variation in the prevailing level of crime opportunities, particularly the ease with which vehicles could be stolen. We interpret the post-1990s cohort effect as triggered by a period effect that operated differentially by age: improved vehicle security reduced juvenile offending dramatically, to the extent that cohorts experienced reduced offending across the life-course. This suggests the prevailing level of crime opportunities in juvenile years is an important determinant of rates of onset and continuance in offending in birth cohorts. We outline additional implications for research and practice.


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