The overall suicide rate in China has dropped substantially since the 1990s, but a slowdown in the decrease and even a reversing trend was observed in specific groups in recent years. This study aims to investigate the latest suicide risk in mainland China by using the age-period-cohort (APC) analysis.
This population-based multiyear cross-sectional study included Chinese ages 10 to 84 years using data from the China Health Statistical Yearbook (2005-2020). Data were analyzed by the APC analysis and intrinsic estimator (IE) technique.
The data satisfactorily fit the constructed APC models. The cohort effect indicated a high risk of suicide among people birth in 1920-1944 and a sharp decline in the 1945-1979 cohort. The lowest risk occurred in the 1980-1994 cohort before a sharp increase in generation Z (birth years in 1995-2009). The period effect showed a declining trend since 2004. The age effect indicated that the suicide risk increased over time, except for a gradual decline from age 35 to 49. The suicide risk increased greatly in adolescents and reached the highest among the elderly.
The aggregated population-level data and the non-identifiability of the APC model could result in bias in the accuracy of results in this study.
This study successfully updated the Chinese suicide risk from the age, period and cohort perspective using the latest available data (2004-2019). The findings enhance the understanding of suicide epidemiology and provide evidence supporting policies and strategies at the macro-level for suicide prevention and management. Immediate action is needed to focus on a national suicide prevention strategy that targets generation Z, adolescents and the elderly which will require a collaborative effort by government officials, public/community health planners and health care agencies.

BACKGROUND: Evidence on historical trends extracted embedded in recent data can advance our understanding of the epidemiology of breast cancer for Chinese women. China is a country with significant political, socioeconomic, and cultural events since the 1900s; however, no such studies are reported in the literature.
METHODS: Age-specific mortality rates of breast cancer during 1990-2015 in China were analyzed using APC modeling (age-period-cohort modeling) method. Net effect from birth cohort was derived to measure cancer mortality risk during 1906-1990 when no mortality data were collected, and net effect from time period was derived to measure cancer mortality risk during 1990-2015 when data were collected. Model parameters were estimated using intrinsic estimator, a novel method to handle collinearity. The estimated effects were numerical differentiated to enhance presentations of time/age trend.
RESULTS: Breast cancer mortality rate per 100,000 women increased from 6.83 in 1990 to 12.07 in 2015. After controlling for age and period, the risk of breast cancer mortality declined from 0.626 in 1906-10 to - 1.752 in 1991-95 (RR = 0.09). The decline consisted of 3 phases, a gradual phase during 1906-1940, a moderate phase with some fluctuations during 1941-1970, and a rapid phase with large fluctuations during 1971-1995. After controlling for age and cohort, the risk of breast cancer mortality increased from - 0.141 in 1990 to 0.258 in 2015 (RR = 1.49) with an acceleration after 2005. The time trends revealed by both the cohort effect and the period effect were in consistency with the significant political and socioeconomic events in China since the 1900s.
CONCLUSIONS: With recent mortality data in 1990-2015, we detected the risk of breast cancer mortality for Chinese women over a long period from 1906 to 2015. The risk declined more than 90% from the highest level in 1906-10 to the lowest in 1990-95, followed by an increase of 49% from 1990 to 2015. Findings of this study connected historical evidence with recent data, supporting further research to exam the relationship between development and risk of breast cancer for medical and health decision-making at the population level and prevention and treatment at the individual level.

OBJECTIVE: Distinctive and dramatic changes in the history of China with a rapid suicide decline in recent years present an opportunity to investigate the risk of suicide. In this study, we investigated suicide risk with a historical perspective with archived data to inform suicide research and prevention policies and strategies.
METHODS: Documented age-specific suicide mortality rates in 1987-2012 were decomposed into age, period, and cohort effect using APC-modeling method and intrinsic estimator (IE) technique. The estimated effects were further analyzed by numerical differentiation.
RESULTS: The data satisfactorily fit the constructed APC models. Cohort effect indicated that suicide risk in China fluctuated at very high levels during 1903-1967, followed by a sharp decline during 1968-1977, and reached the lowest level in 1983-1987 before increased again. Period effect confirmed the declining trend since 1987. Three sunny cohorts with reduced suicide risk and four cloudy cohorts with increased risk were, respectively, associated with significant cultural, social, political, and economic events in China since the 1900s.
CONCLUSIONS: The mega trends in the suicide risk at the population level are closely related to significant historical events in China. Suicide is anticipated to increase because of the growing risk for the young cohorts (particularly young females) as the country further develops. Study findings suggest the significance of national strategies for suicide prevention and control, including maintenance of social harmony and stability, provision of more opportunities for development, enhancement of social integration, and restriction of suicide facilitating factors.