Global, regional, and national time trends in incidence for tuberculosis, 1990-2019: An age-period-cohort analysis for the Global Burden of Disease 2019 study

BACKGROUND

Tuberculosis (TB) represents a significant global health concern, being the leading cause of mortality from a single infectious agent worldwide. The investigation of TB incidence and epidemiological trends is critical for evaluating the effectiveness of control strategies and identifying ongoing challenges.

OBJECTIVES

This study presents the trend in TB incidence across 204 countries and regions over a 30-year period.

METHODS

The study utilises data sourced from the Global Burden of Disease (GBD) database. The age cohort model and gender subgroup analysis were employed to estimate the net drift (overall annual percentage change), local drift (age annual percentage change), longitudinal age curve (expected age ratio), and cycle and cohort effect (relative risk of cycle and birth cohort) of TB incidence from 1990 to 2019. This approach facilitates the examination and differentiation of age, period, and cohort effects in TB incidence trends, potentially identifying disparities in TB prevention across different countries.

RESULTS

Over the past three decades, a general downward trend in TB incidence has been observed in most countries. However, in 15 of the 204 countries, the overall incidence rate is still on the rise (net drift ≥0.0 %) or stagnant decline (≥-0.5 %). From 1990 to 2019, the net drift of tuberculosis mortality ranged from -2.2 % [95 % confidence interval (CI): -2.33, -2.05] in high Socio-demographic Index (SDI) countries to -1.7 % [95 % CI: -1.81, -1.62] in low SDI countries. In some below-average SDI countries,men in the birth cohort are at a disadvantage and at risk of deterioration, necessitating comprehensive TB prevention and treatment.

CONCLUSIONS

While the global incidence of TB has declined, adverse period and cohort effects have been identified in numerous countries, raising questions about the adequacy of TB healthcare provision across all age groups. Furthermore, this study reveals gender disparities in TB incidence.

The influence of age, period, and cohort factors on the incidence of kidney cancer in Spain 1990-2019: Evidence from the global burden of disease study

OBJECTIVE

This study aimed to assess the influence of age, period, and cohort (A-P-C) factors on kidney cancer (KC) incidence trends in Spain from 1990 to 2019.

METHODS

Employing data from the Global Burden of Disease Study 2019, we employed joinpoint analysis to determine long-term patterns and A-P-C modelling to quantify net drift, local drift, longitudinal age curves, and rate ratios (RRs) of period and cohort effects.

RESULTS

Over the period 1990-2019, an estimated 142,811 cases of KC were diagnosed in Spain. A consistent upward trend in KC incidence was observed for both men and women, with the male-to-female ratio remaining stable at 2.6. Joinpoint analysis identified three distinct periods for men: An initial period (1990-1995) characterised by a significant increase in rates, a subsequent period (1995-2016) characterised by a slowdown in the rate of increase, and a final period (2016-2019) in which rates have plateaued. In women, 2 time periods were observed: an initial period (1990-2007) in which rates increased significantly, followed by a period of stabilization (2007-2019). Men born in the early-mid 20th century had a rising KC risk, peaking in the 1960s. Women's risk rose steadily, peaking in the late 1990s.

CONCLUSION

A-P-C analysis reveals steady KC incidence increase in both genders over three decades. This highlights the need for targeted public health policies and effective prevention strategies.

Myelodysplastic syndromes mortality in Spain: a comprehensive age-period-cohort and joinpoint analysis

OBJECTIVE

The present study aims to assess the mortality trends in myelodysplastic syndromes (MDS) in Spain from 1980 to 2021.

METHODS

Deaths and mid-year population data were collected from the National Institute of Statistics. We estimated age-standardised mortality rates (ASMRs) per 100,000 person-years for all ages and ages 35-64. Joinpoint regression identified significant changes in mortality trends. The independent effects of age, period and birth cohort on MDS mortality were also examined.

RESULTS

MDS-related deaths gradually increased from 36 in 1980 to 1118 in 2021, with an overall increase of 6.6% in age-standardised mortality rates (ASMRs) for both men and women. Joinpoint analysis identified four periods for both men and women: 1980-1987 (stable rates), 1987-1990 (sharp increase), 1990-1999 (slower increase) and 1999-2021 (stable rates). ASMRs (35-64 years) increased by 2.5% over the study period, with a turning point identified in 1996 when rates decreased. Mortality from MDS increases with age and is higher in men. The cohort's relative risk increased until the mid-1950s and then stabilised, whilst the period relative risk increased between 1982 and 1996 and then stabilised.

CONCLUSION

The results of this study indicate a progressive increase in MDS-related deaths in Spain between 1980 and 2021. Notably, this increase was more pronounced in men than in women. Analysis of birth cohort trends revealed shifts in MDS risk, characterised by an increase until the mid-twentieth century, followed by a stabilisation. Using joinpoint analysis, four distinct periods were identified, shedding light on the changing patterns of mortality over time. These findings help to shape future research directions and inform public health strategies. They also provide optimism for advances in MDS treatment and potential reductions in mortality.

Trends and age-period-cohort effect on the incidence of falls from 1990 to 2019 in BRICS

Background

The increasing burden of falls in BRICS countries warrants a comprehensive investigation to understand the dynamics and trends. This study utilized data from the Global Burden of Disease Study (GBD) 2019 to assess fall incidence rates in Brazil, Russia, India, China, and South Africa (BRICS) to provide valuable insights for the development of targeted prevention and management strategies.

Methods

Data from the GBD 2019 were employed to estimate fall incidence rates. The study utilized age-period-cohort (APC) model analysis, implemented using R 4.3.0 software and the R package apc, to examine fall incidence trends from 1990 to 2019.

Results

In 2019, the BRICS nations collectively reported 32.32 million fall cases. The overall fall incidence rate increased from 2681.7 per 100,000 people in 1990-2896.3 per 100,000 people in 2019. China and India exhibited escalating trends, with China experiencing the highest growth rate at 21%, followed by India at 5.8%. South Africa displayed a comparatively lower overall incidence rate increase. Notably, the 90-94 age group in China exhibited the most significant deterioration, with men and women experiencing annual increases of 4.23% and 1.77%, respectively. Age effects indicated a higher susceptibility to falls among preschool children and the elderly. Period effects revealed no improvement in the fall state for India (2005-2019) and China (2015-2019). Cohort effects adversely impacted the incidence rate for individuals born earlier in South Africa.

Conclusion

The present study highlights a consistent upward trend in fall incidence rates across BRICS countries from 1990 to 2019. With an aging population, the burden of fall-related diseases is on the rise in these nations. Our results underscore the necessity of formulating evidence-based disease prevention and management approaches tailored to the distinctive demographic attributes of each nation. Addressing these trends is crucial for mitigating the growing impact of falls on public health in BRICS countries.

Reduced burden of Arsenic-Related cancers after water mitigation in Taiwan

BACKGROUND

Epidemiological evidence has demonstrated an association between arsenic in drinking water and increased cancer incidence. This population-based study investigates the impact of a tap water supply system installation in Blackfoot disease-endemic regions of Taiwan on cancer incidence.

METHODS

By using the Taiwan Cancer Registry dataset, we enrolled patients aged 40-84 diagnosed with arsenic-related cancers, including hepatocellular carcinoma, small and squamous cell lung cancer, Bowen's disease, basal and squamous cell skin cancer, urothelial bladder cancer, and upper tract urothelial carcinoma between 1995 and 2019. Random-effects age-period-cohort models were used to estimate the cancer incidence data, and a stabilized kriging method was employed to interpolate incidence rates to more precise spatiotemporal units.

RESULTS

The results showed that the age-standardized incidence rates of all six types of studied cancers were consistently higher in Blackfoot disease-endemic areas than those in other areas from 1995 to 2019. However, the gap in incidence rates between Blackfoot disease-endemic areas and the remaining regions began to narrow approximately after the 1960 birth cohort when the tap water supply system installation commenced. For small and squamous cell lung cancer, Bowen's disease, and urothelial bladder cancer, the excess incidence rates sharply declined to null for those born after the year of arsenic mitigation. For upper tract urothelial carcinoma, the excess incidence rates decreased more gradually for those born after the year of arsenic mitigation. For hepatocellular carcinoma and basal and squamous cell skin cancer, the excess incidence rates remained constant. Spatiotemporal clusters of high incidence rates were identified in the core townships of Blackfoot disease-endemic areas. These clusters began to dissipate mainly after the 1960 birth cohort.

CONCLUSION

Arsenic mitigation from drinking water in Taiwan is associated with a reduced burden of small and squamous cell lung cancers, Bowen's disease, urothelial bladder cancer, and upper tract urothelial carcinoma.

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

BACKGROUND

Although cardiovascular disease mortality rates in the United States declined from the 1970s to 2010s, they have now plateaued. The independent effects of age, period, and birth year (cohort) on cardiovascular disease mortality have not previously been defined.

METHODS

We used data from the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research to examine the effects of age, period, and cohort on cardiovascular disease mortality among individuals aged 20-84 years from 1999 to 2018, prior to the onset of the coronavirus disease 2019 pandemic. Age effects were described as cardiovascular disease-related mortality rates in each 5-year age group adjusted for year of death (period) and year of birth (cohort). Period and cohort effects were quantified as adjusted rate ratios (RRs) comparing cardiovascular disease mortality rates in each period and cohort to the reference periods and reference cohort (ie, 1919 birth cohort), respectively.

RESULTS

Between 1999 to 2018, there were 10,404,327 cardiovascular disease deaths among US adults. In each individual birth cohort, the age-specific cardiovascular disease mortality rates were stable between ages 20 through 39 years. Age-specific rates were higher for each year older between ages 40 through 84 years adjusting for period effects. The period cardiovascular disease mortality rates were lower in later periods (2004-2008 period RR 0.87, 95% confidence interval [CI] 0.85 to 0.88; 2009-2013 period RR 0.78, 95% CI 0.76 to 0.80) compared with the reference period (1999 to 2003) and plateaued thereafter. The cohort cardiovascular disease mortality rates were progressively lower in more recent birth cohorts (1924 birth cohort RR 0.85, 95% CI 0.83 to 0.87; 1974 birth cohort RR 0.29, 95% CI 0.27 to 0.32) compared with the reference cohort (1919 cohort) and plateaued thereafter.

CONCLUSION

Although cardiovascular disease mortality rates declined rapidly among those born between 1919 and 1974, improvements plateaued in birth cohorts thereafter even adjusted for period effects.

Trends in the disease burden of anxiety disorders in middle-aged and older adults in China

BACKGROUND

Anxiety disorders in middle-aged and older adults are an important public health concern in China. Based on the data in the global disease burden (GDB) research database, this study evaluated and analyzed the trend of the disease burden of middle-aged and older patients living with anxiety in China in the past 30 years.

METHODS

The incidence and disability-adjusted life years (DALYs) data of anxiety disorders in China for individuals aged 45-89 years were collected from the Global Burden of Disease Study 2019, and the effects of age, period, and cohort on the incidence of and DALY rate for anxiety disorders were analysed using an age-period-cohort model. Because of the COVID-19 pandemic, the global disease burden research database has not been updated since 2019. However, this did not affect the analysis of future trends in this study, which combined data in the past three decades from 1990 to 2019.

RESULTS

(1) The overall age-standardised incidence rate (ASIR) and age-standardised DALY rate (ASDR) for anxiety disorders in middle-aged and older adults in China decreased by 4.0 and 7.7% from 1990 to 2019, respectively, and the ASIR and ASDR were always higher in women than in men. (2)Age-period-cohort analysis showed that the net drifts for incidence and DALY rate were - 0.27% and - 0.55% per year, respectively. For both genders, the local drifts for incidence were lower than zero in those aged 45-79 years and higher than zero in those aged 80-89 years; the local drifts for the DALY rate were lower than zero in all groups. (3) From the 1990-1994 to 2015-2019, the relative risks of anxiety disorder incidence and DALY decreased by 5.6 and 7.3% in men and 4.3 and 11.7% in women, respectively.

CONCLUSION

The disease burden of anxiety disorders in middle-aged and older adults in China has been relieved over the past 30 years; however, recent ASDR, ASDR, period, and cohort effects have shown adverse trends. The incidence and DALY rate decreased with age in women, while men showed a trend of increasing first and decreasing afterwards.

Global patterns of asthma burden related to environmental risk factors during 1990-2019: an age-period-cohort analysis for global burden of disease study 2019

BACKGROUND

Change in asthma burden attributed to specific environmental risk factor has not been evaluated.

OBJECTIVE

We aimed to explore the age, period, and cohort effects on asthma burden attributable to smoking and occupational asthmagens in different socio-demographic index (SDI) regions and the region and sex disparities.

METHODS

Risk factor-specific asthma deaths and disability-adjusted life years (DALYs) rates were extracted from Global Burden of Disease study 2019, estimated by standard Combined Cause of Death Model and DisMod-MR 2.1 modeling tool. Age-period-cohort analysis was conducted to decompose age, period, and cohort effects on asthma burden.

RESULTS

Smoking- and occupational asthmagens-related asthma deaths and DALYs rates dropped by > 45% during 1990-2019. In 2019, Africa, South and Southeast Asia had higher asthma burden than other regions. Male had higher asthma burden than female. Among nearly all age groups, low-middle SDI region had the highest smoking-related asthma burden, and low SDI region had the highest occupational asthmagens-related asthma burden. Inverse "V" shaped trend was observed in the above regions with increasing age. For smoking-related asthma deaths and DALYs rates, the most significant improvement of period rate ratio (RR) occurred in high SDI region, decreased from 1.67 (1.61, 1.74) to 0.34 (0.33, 0.36) and 1.61 (1.57, 1.66) to 0.59 (0.57, 0.61), respectively, as well as the cohort effect on smoking-related asthma burden. For occupational asthmagens-related asthma deaths and DALYs rates, the most sharply decrease of period and cohort RR appeared in the high and high-middle SDI regions. Low SDI region showed least progress in period and cohort RR of smoking- and occupational asthmagens-linked asthma burden.

CONCLUSION

Smoking- and occupational asthmagens-related asthma burden sharply decreases, but region and sex disparities exist. Policy makers from low SDI region should reinforce tobacco control and prioritize workplace protection.

The reduced mortality of malignant melanoma at the population level is mainly attributable to treatment advances for the past decade

BACKGROUND

Cutaneous malignant melanoma (CMM) causes most skin cancer deaths in the United States (US). The mortality has been decreasing in the US population. We hypothesize that this population-level reduction is mainly attributable to the treatment advances, rather than the successful primary and secondary prevention.

METHODS

Using data from the Surveillance, Epidemiology, and End Results (SEER) databases, we collected the incidence, incidence-based mortality (IBM), and 5-year survival (5-YS) rates of CMM from 1994 to 2019. Trends by stage and sex were examined by joinpoint regression analyses and age-period-cohort analyses.

RESULTS

The overall incidence of CMM rose by 1.6% yearly from 1994 to 2006 (95% confidence interval [CI]: 0.9% to 2.2%) and then increased with a numerical trend. And we projected the incidence will continue to increase until 2029. In contrast, the IBM for all CMM has decreased yearly by 2.8% (95% CI: -3.9% to -1.8%) since 2010 after continuously increasing by 3.8% annually (95% CI: 3.2% to 4.4%) from 1996 to 2010. For early-stage (localized and regional) CMM, we found the incidence since 2005 plateaued without further increase, while the incidence for CMM at distant stage continuously increased by 1.4% per year (95% CI: 0.9% to 2.0%). Improvements in 5-YS were observed over the study period for all CMM and were most obvious in distant stage. And significant period effects were noted around the year 2010.

CONCLUSION

This study demonstrated improved survival and reduced mortality of CMM at the US population level since 2010, which were consistent with the introduction of novel therapies. Encouraging effects of primary prevention among adolescents in the most recent cohorts were found. However, the plateaued overall incidence and early diagnosis rates indicated that advances in primary and secondary prevention are very much needed to further control the burden of CMM.

Colorectal cancer and its attributable risk factors in East Asia, 1990-2030

BACKGROUND

The disease burden of colorectal cancer in East Asia has been at a high level. However, the epidemiological characteristics of the disease burden in this region have not been systematically studied.

METHOD

Data were obtained from the Global Burden of Disease 2019 program. Joinpoint analysis was used to identify long-term trends in mortality of colorectal cancer. Independent effects of age, period, and cohort were detected by the age-period-cohort model. The Bayesian age-period-cohort model was performed to predict the burden of colorectal cancer across East Asia by 2030.

RESULTS

From 1990 to 2019, the average annual percentage change (AAPC) showed upward trends in mainland China (1.05 [95% confidence interval (CI)], 0.82, 1.28) as well as Taiwan Province of China (1.81 [95% CI], 1.51, 2.10) but downward in Japan (-0.60 [95% CI], -0.70, -0.49) (P < 0.05). Attributable risk factors for colorectal cancer in East Asia remained stable over 30 years, while the risk of metabolic factors is noteworthy in the future. In the next decade, the age-standardized death rate (ASDR) of colorectal cancer in China was predicted to surpass that of Japan and South Korea in expectation.

CONCLUSION

The mortality of colorectal cancer is escalating in developing countries, while it is gradually declining in high-income countries across East Asia. Nonetheless, the disease burden of colorectal cancer in high-income countries remains substantial level.

Decrease in household secondhand smoking among Korean adolescents associated with smoke-free policies: grade-period-cohort and interrupted time series analyses

OBJECTIVES

Smoke-free areas have expanded and related campaigns have been implemented since 1995 in Korea. As a result, household secondhand smoke (SHS) exposure has decreased over the past 15 years. We assessed the cohort effect, the effect of a 2008 campaign on household SHS exposure, and the impact of a complete smoking ban in public places along with increased penalties, as implemented in December 2011.

METHODS

Nationally representative cross-sectional 15-wave survey data of Korean adolescents were used. The 810,516 participants were classified into 6 grade groups, 15 period groups, and 20 middle school admission cohorts. An age-period-cohort analysis, conducted with the intrinsic estimator method, was used to assess the cohort effect of household SHS exposure, and interrupted-time series analyses were conducted to evaluate the effects of the smoke-free policy and the campaign.

RESULTS

For cohorts who entered middle school from 2002 to 2008, the risk of household SHS exposure decreased among both boys and girls. Immediately after implementation of the smoke-free policy, the prevalence of household SHS exposure by period decreased significantly for boys (coefficient, -8.96; p<0.05) and non-significantly for girls (coefficient, -6.99; p=0.07). After the campaign, there was a significant decrease in household SHS exposure by cohort among boys, both immediately and post-intervention (coefficient, -4.84; p=0.03; coefficient, -1.22; p=0.02, respectively).

CONCLUSIONS

A school-admission-cohort effect was found on household SHS exposure among adolescents, which was associated with the smoke-free policy and the campaign. Anti-smoking interventions should be implemented consistently and simultaneously.

Epidemiology of Lung Cancer Mortality in Spain: Updated Information (1982-2021) and Predictions up to 2046

BACKGROUND

Patterns of lung cancer (LC) mortality are important for planning health services and resource management.

OBJECTIVES

We aimed to provide updated information (1982-2021) and project (LC) mortality rates in Spain (2022-2046).

METHOD

We analysed data from the Spanish National Statistics Institute about mortality in LC (1982-2021), and we made predictions for the period 2022-2046.

RESULTS

In 2021, a total of 22,413 people died of LC, and for the period 2042-2046, the projected annual average was 25,549 deaths. In males, age-standardised mortality rates (ASMR) (overall) after an initial period of increase (1982-1996, 2.2%) declined until 2021 (-1.4% per year), and this decline is expected to continue in the future (-1.9% per year during the period 2022-2046), although the projected decline is slightly higher (-2.0% during the period 2022-2046). In men, ASMR (all ages) after an initial period of increase (1982-1996, 2.2%) declined until 2021 (-1.4% per year), and this decline is expected to continue in the future during the period 2022-2046. In women, both the overall and truncated rates (35-64) increase during the period 1982-2021 (4.1% and 6.0% per year, respectively), and projected rates showed that both will decrease during the period 2022-2046, although more markedly in the truncated rates (-1.9% per year) than in the overall rates (-0.5% per year).

CONCLUSIONS

Our projections show the magnitude of a steady upward trend in LC mortality among women in Spain that appears to be beginning to reverse from the current decade (similar to that observed for incidence).

Global, regional, and national burden of intestinal obstruction from 1990 to 2019: an analysis from the Global Burden of Disease Study 2019

BACKGROUND

Intestinal obstruction (IO) is a common surgical acute abdominal condition that places a significant burden on modern health systems. Unfortunately, the global burden and trends of IO remain unknown. Therefore, this study aimed to comprehensively assess its long-term trends and epidemiological features, which will help policymakers to formulate appropriate health policies.

METHODS

We conducted an ecological study using data from the Global Burden of Disease Study (GBD) 2019. Data on IO were analyzed by sex, age, year, sociodemographic index (SDI), and location according to GBD 2019. In addition, joinpoint regression analysis was used to assess temporal trends. Age-period-cohort analysis (APC Analysis) was conducted to evaluate age, period, and birth cohort effects on IO incidence and mortality risk.

RESULTS

Globally, the prevalent and incident cases increased by 56.91% and 86.67% from 1990 to 2019, respectively. Joinpoint regression analysis showed that age-standardized incidence rate (ASIR) and age-standardized prevalence rate (ASPR) increased, but age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life year (DALY) rate decreased over the past three decades. The age effect demonstrated that older people have a higher risk of morbidity and mortality. The period effect of incidence and mortality showed an upward trend from 1990 to 2019. Cohort effect revealed that the incidence and death risk peaked in the earlier-born cohort and was lower in the more recent-born cohort. Notably, we found that the burden of IO was higher in males than in females throughout the study period. There are huge disparities in IO burden among countries.

CONCLUSION

Globally, the reported incidence and prevalence of IO increased from 1990 to 2019. The burden of IO differed markedly by age, sex, country, and region. Middle-aged and elderly people over 50 years old were at high risk. Given the ageing population, the burden of IO will be a major public health challenge. Thus, there is a strong necessity to strengthen prevention and early intervention in the at-risk population.

Trends and patterns in stroke incidence, mortality, DALYs and case-fatality by sociodemographic index worldwide: an age-period-cohort analysis using the Global Burden of Disease 2019 study

OBJECTIVES

Stroke is a significant public health burden worldwide. This study aimed to explore the trends and patterns of stroke incidence, mortality, disability-adjusted life years (DALYs) and case-fatality percent (CFP) worldwide from 1990 to 2019.

STUDY DESIGN

Age-period-cohort analysis.

METHODS

Trends in stroke burden worldwide were evaluated using data from the Global Burden of Disease 2019 study. In addition, the relationship between the burden of stroke and sociodemographic index (SDI) was examined by quantile regression. Age, period and cohort patterns in stroke burden across different SDI groups were estimated using age-period-cohort analysis.

RESULTS

Between 1990 and 2019, the age-standardised rates (ASRs) of stroke incidence, mortality and DALYs declined significantly worldwide, with decreases of -16.89% (95% uncertainty interval [UI]: -18.41 to -15.29), -36.43% (95% UI: -41.65 to -31.20) and -35.23% (95% UI: -40.49 to -30.49), respectively. Regions with ASRs in the 75th percentile and below experienced significant decreases in ASRs with increasing SDI. After 2014, there was a stable or slightly increased period effect for stroke incidence in all groups, while mortality, DALYs and CFP increased only in the high SDI group. The cohort effect of stroke incidence remained constant in the high SDI group from the 1960-1964 cohort onwards.

CONCLUSIONS

Although high SDI regions had a lower stroke burden and a faster overall decline in burden, the recent relative risk data suggest a potential deceleration in the progress of reducing stroke burden in these areas. There is a need for more active measures to reduce the stroke burden in areas with the highest incidence, mortality and DALYs, as increasing SDI alone cannot lower the burden in these regions.

Secular trend of mortality and incidence of rheumatoid arthritis in global ,1990-2019: an age period cohort analysis and joinpoint analysis

BACKGROUND

Rheumatoid arthritis (RA) is a major public health problem. Unfortunately, there is a scarcity of comprehensive and up-to-date information regarding the burden of RA and its dynamic trends in subsequent years. To examine the changing trends in the global burden of RA and forecast for 2044, which will facilitate the development of strategies tailored to RA burden and provide reference for the development of effective treatment guidelines.

METHODS

Following the general analytical strategy used the Global Burden of Disease Study (GBD) 2019, which included 204 countries, the age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR) and age-standardized disability adjusted of life year (DALY) rate for RA were analyzed.

RESULTS

The ASIR, ASMR and age-standardized DALY rate for RA in 2019 were 13.001/100,000 (95% UI, 11.833 ~ 14.274), 0.574/100,000 (95% UI, 0.356 ~ 0.793) and 39.565/100,000 (95% UI, 49.529 ~ 30.508), respectively. America had the highest ASIR [18.578(95% UI, 17.147 ~ 20.148)] and age-standardized DALY rate [53.676(95% UI, 40.106 ~ 67.968)] in 2019. Asia had the highest ASMR [0.681(95% UI, 0.802 ~ 0.480)] in 2019. From 1990 to 2019, a significant average annual percentage change (AAPC) in the ASIR was observed in both males [0.237% (95% CI, 0.216 ~ 0.259%)] and females [0.197% (95% CI, 0.141 ~ 0.254%)], AAPC in the ASMR was observed in both males [-0.398% (95% CI, -0.605~-0.191%)] and females [-0.295% (95% CI, -0.424~-0.65%)]. Age effects indicated that the relative risk (RR) of RA-associated incidence and mortality rates increased with age among males and females. The RR of RA increased over time and started to gradually increase from 1990. Cohort effects showed decreases in incidence, mortality and DALY rates in successive birth cohorts. The global incidence of RA would continue to increase in the future, while mortality would continue to decrease.

CONCLUSION

The increased risk of RA is dominantly influenced by age effects and period effects and the ethnic area. The results suggest that early identification and treatment of RA is important for reducing the ongoing burden with age, and targeted health education and specific intervention programs should be promoted to control middle-elderly population.

New evidence of trends in cognitive function among middle-aged and older adults in China, 2011-2018: an age-period-cohort analysis

BACKGROUND

Increasing evidence from high-income countries suggests the risk of cognitive impairment has been declining recently. However, related studies in China have rarely been done, and the results are inconsistent. We analyze the trends in cognitive function among middle-aged and older adults in China between 2011 and 2018.

METHODS

We used data from four waves of the China Health and Retirement Longitudinal Study (CHARLS), including 48918 individuals aged 45 years and older. Cognitive function was assessed using the CHARLS cognitive measures containing episodic memory, orientation, attention, and visuospatial abilities. The hierarchical age-period-cohort (APC) model was used to quantify the separate age, period, and cohort effects on trends in cognitive function.

RESULTS

The study sample's ages ranged from 45 to 105 years (Mean = 59.2, SD = 9.4). Cognitive function declined with age net of period and cohort effects, an apparent acceleration in the rate of cognitive decline after age 65 was found adjusting for individual characteristics. Although period effects on trends in cognitive function remained stable during the study period, hierarchical APC models demonstrated significant cohort variations. Independent of age and period effects, there was a fluctuating trend across cohorts before 1960 and an overall decline across successive cohorts.

CONCLUSIONS

Our study indicates that the age effect remains the most crucial factor regarding cognitive decline. Moreover, results demonstrate that cohorts living in social upheaval leading to educational deprivation and/or nutritional deficiency in early life may face a higher risk for cognitive deterioration later in life. Such findings indicate that dementia prevention from a life course perspective and cohort-specific strategies are critical to alleviating the future public-health burdens related to cognitive aging. Ongoing attention should be paid to the role of cross-cohort differences in education on cohort trends in cognition in countries like China that are aging rapidly and have a late start in educational expansion compared to other countries. Other factors, such as environmental stimulation, need to be noticed in younger cohorts.

Secular trends of low birth weight, preterm birth, and small for gestational age in Shanghai from 2004 to 2020: an age-period-cohort analysis

BACKGROUND

Although highly heterogeneous among countries, the incidence rates of low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA) have been increasing globally over the past two decades. To better understand the cause of these secular trends, this study aimed to investigate the effects of age, period, and birth cohort on LBW, PTB, and SGA rates in Shanghai.

METHODS

Data from 2,958,695 singleton live births at 24-41 gestational weeks between 2004 and 2020 were obtained for this study. Age-period-cohort models based on Poisson regression were used to evaluate the independent effects of maternal age, delivery period, and maternal birth cohort on the trends in LBW, PTB, and SGA.

RESULTS

The overall prevalence rates of LBW, PTB, and SGA were 2.9%, 4.7%, and 9.3%, respectively, and significant changes were observed (average annual change: + 10.7‰, + 9.1‰, -11.9‰) from 2004 to 2020. Cohort effect increased steadily, from 1960 (risk ratio [RR] = 0.71, 95% confidence interval [CI]: 0.65-0.78) to 1993 (RR = 0.97, 95% CI: 0.94-1.01) for LBW and from 1960 (RR = 0.69, 95% CI: 0.64-0.75) to 2004 (RR = 1.02, 95% CI: 0.94-1.12) for PTB. A strong cohort effect was found with the highest risk of SGA (RR = 1.82, 95% CI: 1.72-1.93) in 1960 and the lowest risk (RR = 0.57, 95% CI: 0.54-0.61) in 2004, compared with the reference cohort of 1985. There was a "U-shaped" maternal age effect on LBW and PTB and a weak period effect on the three birth outcomes.

CONCLUSIONS

Our findings suggested a significant independent effect of age, period, and birth cohort on the three birth outcomes. The increasing rates of LBW and PTB motivated us to focus on young and advanced pregnant women. Meanwhile, the prevalence of SGA decreased steadily, illustrating the need for further research on the mechanisms underlying these trends.

Analysis of age, period, and birth cohort effects on suicide mortality in Brazil and the five major geographic regions

OBJECTIVE

Estimate the effects of age, period, and birth cohort on suicide mortality in Brazil by major geographic region in the overall population and by sex.

METHODS

This was a time trend ecological study. National and regional suicide mortality data from 1981 to 2020 were analyzed for the overall population and by sex. Age, period, and cohort effects were calculated with a Poisson regression model using estimable functions with the Epi package of the R statistical program, version 4.2.1.

RESULTS

There were 272,716 suicides in individuals ranging from 20 to 79 years old. In the overall population, the age model-adjusted suicide mortality rates showed an upward pattern for Brazil. The most recent cohort showed the highest associated risk, 1.67 (95%CI 1.63; 1.71), while for the reference period, it was the highest risk among all the periods.

CONCLUSIONS

Suicide mortality rates have shown an upward trend with advancing age in both men and women in the Brazilian population. However, the behavior of the period effect and cohort depends on the population analyzed and regional distribution.

Global, regional, and national burden of asthma and its attributable risk factors from 1990 to 2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

The burden of asthma in terms of premature death or reduced quality of life remains a huge issue. It is of great importance to evaluate asthma burden geographically and time trends from 1990 to 2019 and to assess the contributions of age, period, and cohort effects at global level.

METHODS

Asthma prevalence, deaths, and disability adjusted life years (DALYs) as well as risk-attributable burden were collected from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 database and were compared by age and sex. The Smoothing Splines models were used to estimate the relationship between asthma DALYs and the sociodemographic index (SDI). The Age-Period-Cohort model was used to determine effects of ages, periods, and birth cohorts on disease rates.

RESULTS

Between 1990 and 2019, the declines were 24.05% (95% uncertainty interval [UI] - 27.24 to - 20.82) in age-standardized asthma prevalence, 51.3% (- 59.08 to - 43.71) in mortality, and 42.55% (- 48.48 to - 36.61) in DALYs rate. However, the burden of asthma continued to rise, with an estimated 262.41 million prevalent cases globally (95% UI 224.05 to 309.45). Asthma caused greater DALYs in females than in males among people aged 20 years and older. The lowest age-standardized DALYs rate was observed at a SDI of approximately 0.70. The Longitudinal age curves showed an approximate W-shaped pattern for asthma prevalence and a likely J-shaped pattern for asthma mortality. The period effect on prevalence and mortality of asthma decreased from 1990 to 2019. Compared with the 1955-1959 birth cohort, the prevalence relative risk (RR) of asthma was highest in the 1905-1909 birth cohort, whereas the mortality RR continued to decline. At the global level, the percentages of high body-mass index, occupational asthmagens, and smoking contributing to DALYs due to asthma were 16.94%, 8.82%, and 9.87%, respectively.

CONCLUSIONS

Although the age-standardized rates of asthma burden declined in the past 30 years, the overall burden of asthma remains severe. High body mass index becomes the most important risk factor for DALYs due to asthma at the global level.

Mortality trends and disease burdens of cervical, endometrial and ovarian cancers from 1981 to 2020 in Taiwan

Cervical, endometrial, and ovarian cancers are major gynecologic cancers in Taiwan. Although cervical cancer has received attention through nationwide screening program and the rollout of the human papillomavirus vaccine, endometrial and ovarian cancers have attracted less attention. The age-period-cohort analysis of constant-relative-variation method was used to estimate the mortality trends of cervical, endometrial, and ovarian cancers for population aged 30-84 years during 1981-2020 in Taiwan. The years of life lost was used to estimate the disease burden due to premature death from gynecological cancers. The age effect of endometrial cancer mortality was greater than those of cervical and ovarian cancers. The period effects decreased during 1996-2000 for cervical cancer and plateaued for endometrial and ovarian cancers during 2006-2020. The cohort effect decreased after the birth year 1911 for cervical cancer, increased after 1931 for endometrial cancer, and increased in all birth years for ovarian cancer. For both endometrial and ovarian cancers, the Spearman's correlation coefficients revealed the strong negative correlations between the fertility and the cohort effects, and the strong positive correlations between the average age at first childbirth and the cohort effects. The burden of premature death from ovarian cancer was higher than those of cervical and endometrial cancers during 2016-2020. Due to increasing cohort effect and burden of premature death, endometrial and ovarian cancers will become the largest threat to women's reproductive health in Taiwan.

Effect of Age and Sex on Stroke Mortality of Young and Middle-aged Adults in China, 2002-2019, and Predictions to 2030

OBJECTIVE

This study aimed to examine the trends in stroke mortality among young and middle-aged adults in China.

METHODS

Data were obtained from the China national vital registration system. Significant changes in mortality were assessed by Joinpoint regression. Age-period-cohort analysis was used to explain the reasons for the changes. Future mortality and counts were predicted by the Bayesian age-period-cohort model.

RESULTS

Between 2002 and 2019, a total of 6,253,951 stroke mortality in young and middle-aged adults were recorded. The age-adjusted mortality rates (AAMRs) of women showed a downward trend. The annual percent changes (APC) were -3.5% (-5.2%, -1.7%) for urban women and -2.8% (-3.7%, -1.9%) for rural women. By contrast, the AAMRs per 100,000 for rural men aged 25-44 years continued to rise from 9.40 to 15.46. The AAMRS for urban men aged 25-44 years and urban and rural men aged 45-64 years did not change significantly. Between 2020 and 2030, the projected stroke deaths are 1,423,584 in men and 401,712 in women.

CONCLUSION

Significant sex and age disparities in the trends of stroke mortality among young and middle-aged adults were identified in China. Targeted health policy measures are needed to address the burden of stroke in the young generation, especially for rural men, with a focus on the prevention and management of high risk factors.

Age-period-cohort effect on lung cancer mortality in Spain, 1982-2021

BACKGROUND

The aim of the study is to provide up-to-date information and evaluate the age-period-cohort effects of age-period cohorts on lung cancer (LC) mortality in Spain for the period 1982 to 2021.

METHODS

We analysed deaths by LC and population for the period 1982-2021, available from the Spanish National Institute of Statistics. The LC corresponds to code 162 and codes C33 and C34 of the 9th and 10th editions of the International Classification of Diseases, respectively. Age-period-cohort (A-P-C) modelling was applied to compute the net drift, local drift, longitudinal age curve, and rate ratios (RR) of each period and cohort. A-P-C analysis was performed using the A-P-C Web Tool provided by the National Cancer Institute of the United States.

RESULTS

Estimated relative risk in the male birth cohorts has followed a steady downward trend in all cohorts born since 1922, showing an initial period (1922-1947) of slight decline, followed by a more marked decrease in the cohorts born during the period 1947-1977. In the younger cohorts (1977-1997), the decline appears to have stabilised. In women, a strong cohort effect is observed. In those born after the Spanish Civil War (1936 to 1939), the risk increased until it peaked in the 1960s, after which it started to decrease with the same intensity. Period RR in men decreased from 1987 to 1991 (1.1) to 2017-2021 (0.6), while period RR in women increased during this time (from 0.8 to 1.6).

CONCLUSIONS

The cohort effect observed in women born after the Civil War suggests that the onset of the LC epidemic may have been due to a higher prevalence of women smokers in these cohorts. However, the trend observed in the younger cohorts suggests a possible slowing-down in the increase in mortality risk in the following years.

Prenatal exposure to famine and the development of diabetes later in life: an age-period-cohort analysis of the China health and nutrition survey (CHNS) from 1997 to 2015

PURPOSE

Prenatal exposure to famine has been linked to increased diabetes risk in adulthood. However, one fundamental issue to be addressed is that the reported famine-diabetes relation may be confounded by the age differences between the exposed and non-exposed groups. We aimed to determine the association between prenatal exposure to the Chinese famine of 1959-1962 and risk of diabetes by applying age well-controlled strategies.

METHODS

Among 20,535 individuals born in 1955-1966 who participated in the China Health and Nutrition Survey from 1997 to 2015, we constructed age-matched exposed vs. non-exposed groups to investigate the role of prenatal exposure to the Chinese famine of 1959-1962 in relation to diabetes. We also built a hierarchical age-period-cohort (HAPC) model to specifically examine the relation of famine to diabetes risk independent of age.

RESULTS

Compared to the age-balanced men in the non-exposed group, the exposed men born in 1961 had a 154% increased risk of diabetes [odds ratio (OR) 2.54 (95% CI 1.07-6.03), P = 0.04). In the HAPC analysis, the predicted probabilities of diabetes peaked in the 1961-birth cohort of men [3.4% (95% CI 2.4%-5.0%)], as compared to the average probability of diabetes (reference) of 1.8% for men overall. Neither analytical strategy revealed any strong relation between famine exposure and diabetes risk in women.

CONCLUSION

Among the pre-defined Chinese famine period of 1959-1962, early-life exposure to famine was associated with increased diabetes risk in men but not in women, and these relations were independent of age.

Alcohol or Drug Self-Help Use Among Adults in the United States: Age, Period, and Cohort Effects Between 2002 and 2018

In the context of an ongoing and worsening drug overdose epidemic in the USA, increases in free support services like self-help groups may be expected. We estimated differences in self-help use by age, period, or cohort among people who may have needed treatment. We included N = 92,002 adults from the 2002-2018 National Surveys on Drug Use and Health who met past-year DSM-IV substance use disorder criteria or received alcohol/drug treatment in any location. We used hierarchical age-period-cohort (HAPC) modeling to estimate average age-period-cohort associations with self-help. Level-1 covariates included age, race and ethnicity, household income, and sex. We quantified level-2 variance components using the median odds ratio (MOR). We found small positive HAPC period effects for alcohol/drug self-help that were driven by alcohol-specific effects. Birth cohort differences were observed starting at age 48. Younger birth cohorts, especially among Black adults, were less likely to report self-help use than older birth cohorts. MOR was consistently elevated for cohort effects (MOR = 1.17; covariance parameter: 0.15; 95% CI [0.11, 0.23]) but not for period effects. Overall, self-help use did not increase in the context of substantial treatment needs and worsening overdose racialized disparities. Instead, cohort effects explained trends in alcohol/drug self-help. Findings could indicate that younger birth cohorts may need additional supports, especially services tailored for Black and Hispanic people.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11469-023-01012-2.

Trends of ischemic heart disease mortality attributable to household air pollution during 1990-2019 in China and India: an age-period-cohort analysis

Cardiovascular diseases (CVD) caused by household air pollution (HAP) have sparked widespread concern globally in the recent decade. Meanwhile, increased ischemic heart disease (IHD) mortality has been the leading cause of worldwide CVD deaths. Both China and India experienced a high IHD burden and high exposure to HAP. The present study aimed to estimate and compare the long-term trends of HAP-attributable IHD mortality in the two countries. The data of this study were extracted from the Global Burden of Diseases (GBD) Study 2019. The age-period-cohort (APC) analysis was utilized to estimate the independent trends of the age, period, and cohort effects from 1990 to 2019. The age-standardized mortality rates (ASMRs) of HAP-attributable IHD have fallen faster in China than in India for both sexes. The local drift and net drift values were < 0 for all age groups in both countries. The age effects in both countries and sexes increased with time, suggesting age is a risk factor for IHD; conversely, period and cohort effects in China demonstrated a faster decline in both genders than in India. It indicated that China has been more successful than India in decreasing HAP-attributable IHD mortality.

Incidence and mortality trends of nasopharynx cancer from 1990 to 2019 in China: an age-period-cohort analysis

Background

Nasopharynx cancer (NPC) is a great health burden in China. This study explored the long-term trends of NPC incidence and mortality in China.

Methods

We retrospectively analyzed data from the Global Burden of Disease Study 2019 using an age-period-cohort framework.

Results

The age-standardized incidence rate (ASIR) of NPC increased by 72.7% and age-standardized mortality rate (ASMR) of NPC decreased by 51.7% for both sexes between 1990 and 2019. For males, the local drift for incidence was higher than 0 (P < 0.05) in those aged 20 to 79 years. For females, the local drift was higher than 0 (P < 0.05) in those aged 30 to 59 years, and lower than 0 (P < 0.05) in those aged 65 to 84 years. The local drift for mortality rates were less than 0 (P < 0.05) in every age group for both sexes. The estimated period relative risks (RRs) for incidence of NPC were increased monotonically for males, and increased for females after 2000. The increasing trend of cohort RRs of incidence was ceased in recent birth cohorts. Both period and cohort effects of NPC mortality in China decreased monotonically.

Conclusions

Over the last three decades, the ASMR and crude mortality rate (CMR) of NPC has decreased, but the ASIR and crude incidence rate (CIR) increased in China. Although the potential mortality risk of NPC decreased, the risk of NPC incidence was found to increase as the period move forward, and suggested that control and prevention efforts should be enhanced.

Why birth cohorts commit crime at different rates

Crime rates respond to age shifts in the population and to changes in current social conditions. A flexible generalization of the characteristic solution to the age-period-cohort problem shows that they also respond to differences in birth cohorts. I used age-arrest data for a representative panel of 16 states to estimate annual differences in cohort effects, then regressed them on 21 covariates spanning a wide range of social, economic, and environmental conditions. Cohort effects explained both the 1960-1990 crime increase and the post-1990 crime drop about as effectively as current conditions; the covariates explained about half of these effects. Cohort criminality was primarily affected by three conditions: relative cohort size; the prevalence of crime during childhood; and the capacity of families and neighborhoods to socialize children. Because all of these characteristics are trending in favorable directions, cohort effects - and crime rates - will probably continue to decline.

Incidence trends of major depressive disorder in China: an age-period-cohort modeling study

BACKGROUND

Major depressive disorder (MDD) is a common public health problem in China. However, few studies have focused on its incidence and separated age, period, and cohort effects. This study aimed to assess the age, period, and cohort effects on the incidence trends of MDD in China between 1993 and 2017.

METHODS

The incidence data of MDD were obtained from the Global Burden of Diseases Study 2017. Age-period-cohort modeling method was used to separate the age, period, and cohort effects on MDD incidence rate.

RESULTS

The incidence number of MDD increased by 22.8% while the age-standardized incidence rate decreased by 15.6% over 25 years. Age-period-cohort analysis indicated that the net drift was -0.433% per year, with -0.486% for females and -0.385% for males. For both sexes, the local drifts were all <0 in 10 to 54 years age groups but >0 in 55 to 94 years age groups. The longitudinal age curves of MDD incidence basically showed an increasing trend, except for a subpeak at 20-24 years age group. The period rate ratio largely declined over time, except for an uptick after 2003-2007. The cohort rate ratio followed an inverted U-shaped pattern and was highest in 1951-1955 birth cohort.

LIMITATIONS

The MDD data were estimated and wide social factors were not included in the analyses.

CONCLUSION

The changes of MDD incidence rate in China are likely to be related to rapid social and economic development, and major historical events. However, the associations need to be interpreted with caution.

Increases in Height among Chinese Children and Adolescents by Gender: An Age-Period-Cohort Analysis

OBJECTIVE

To examine increases in average height among Chinese children and adolescents.

METHODS

The data were obtained from the China Health and Nutrition Survey conducted during the period 1989-2015. A stratified multistage cluster sampling method was utilized to select participants aged 2-22 years in each province. Linear regression was used to examine the effects of age, birth cohort, and survey period on height.

RESULTS

A total of 15,227 males and 13,737 females were included in the final analysis. Age (A) showed a continuous effect on height. The average heights of the investigated groups increased continuously during the investigation period. By 2015, the average height of the overall group increased by 7.87 cm compared to the average height during the 1989 survey. Moreover, birth year (cohort, C) also had a stable effect on height. Using the height of individuals born in or before 1975 as a reference, the average height of each birth cohort increased in comparison to the previous birth cohort.

CONCLUSIONS

The height of Chinese children and adolescents was affected by age, period, and cohort effects, and this effect is governed by certain rules. The age-period-cohort model can be used to analyze the trends of children's and adolescent's heights. The findings provide a scientific basis for the formulation of children's and adolescents' growth and development policies in China.

The epidemiological trends in the burden of lung cancer attributable to PM2.5 exposure in China

Objective

PM_2.5, which is a major contributor to air pollution, has large effects on lung cancer mortality. We want to analyse the long-term trends in lung cancer burden attributable to PM_2.5 exposure and provide evidence that can be used for preventive measures and health resource planning.

Methods

Mortality data related to lung cancer were obtained from the Global Burden of Disease (GBD) 2019 project. A joinpoint regression analysis was used to assess the magnitude and direction of the trends in mortality from 1990 to 2019, and the age-period-cohort method was used to analyse the temporal trends in the mortality rate of lung cancer attributable to PM_2.5 exposure by age, period, and cohort.

Results

From 1990 to 2019, the age-standardized mortality rate (ASMR) attributable to PM_2.5 exposure trended slowly upwards, and the ASMR due to ambient PM_2.5 exposure (APE) increased significantly, that due to household PM_2.5 exposure (HPE) decreased. The longitudinal age curves show that the mortality rates due to PM_2.5 exposure among younger individuals were low, and they significantly increased from their levels among those in the 45–49 age group to their levels among those in the over-85 age group. From 1990 to 2019, the period RRs due to APE increased, but those due to HPE decreased. Similar trends were observed in the cohort RRs. The overall net drift per year attributable to PM_2.5 exposure was below 0. The local drift values increased with age and were above 0 for the over-80 age groups. The overall net drifts per year were above zero for APE and below zero for HPE. The corresponding results among males were higher than those among females.

Conclusions

In China, the type of air pollution responsible for lung cancer has changed from household air pollution to ambient air pollution. PM_2.5 exposure is more harmful among males and older people. Ambient air pollution should be emphasized, and China should strengthen its implementation of effective public policies and other interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10765-1.

An age-period-cohort analysis for prevalence of common psychiatric disorders in Japan, 1999-2017

PURPOSE

This study aimed to analyze the prevalence of common psychiatric disorders in Japan via an age-period-cohort (APC) analysis.

METHODS

Data were used on the prevalence of schizophrenia, schizotypal, and delusional disorders; mood [affective] disorders (mood disorders, hereafter); and neurotic, stress-related, and somatoform disorders from the 1999-2017 Patient Survey in Japan. The age group was defined as 20-89 years with 5-year increments; the cohort was assigned for each age group of each year with a 1-year shift. A Bayesian APC analysis was used to decompose changes in prevalence into three effects: age, period, and cohort.

RESULTS

The APC analysis revealed that the peaks of age effect varied among sexes and diseases. The period effects for all the diseases showed increasing trends over the analyzed years. Although the cohort effect for the prevalence of schizophrenia, schizotypal, and delusional disorders increased until the 1960s, it decreased afterwards. On the other hand, the cohort effects for the prevalence of mood disorders and neurotic, stress-related, and somatoform disorders increased from around the 1950s, and it indicates the prevalence increased particularly in young ages over the years. Also, the trends of each effect were relatively similar between mood disorders and neurotic, stress-related, and somatoform disorders.

CONCLUSION

Increase in public awareness and psychological stress associated with a change in a social environment is thought to affect the period and cohort effects on the prevalence of mood disorders and neurotic, stress-related, and somatoform disorders.

THE USES AND ABUSES OF AN AGE-PERIOD-COHORT METHOD: ON THE LINEAR ALGEBRA AND STATISTICAL PROPERTIES OF INTRINSIC AND RELATED ESTIMATORS

As a sophisticated and popular age-period-cohort method, the Intrinsic Estimator (IE) and related estimators have evoked intense debate in demography, sociology, epidemiology and statistics. This study aims to provide a more holistic review and critical assessment of the overall methodological significance of the IE and related estimators in age-period-cohort analysis. We derive the statistical properties of the IE from a linear algebraic perspective, provide more precise mathematical proofs relevant to the current debate, and demonstrate the essential, yet overlooked, link between the IE and classical statistical tools that have been employed by scholars for decades. This study offers guidelines for the future use of the IE and related estimators in demographic research. The exposition of the IE and related estimators may help redirect, if not settle, the logic of the debate.

Recent incidence trend of elderly patients with glioblastoma in the United States, 2000-2017

Background

The incidence of glioblastoma increases significantly with age. With the growing and aging population, there is a lack of comprehensive analysis of recent glioblastoma incidence trend in the United States. This study aims to provide in-depth description of the patterns of incidence trends and to examine the age-period-cohort effects to the trends of glioblastoma specific to elderly patients.

Methods

The incidence rates were age-adjusted and reported per 100,000 population. We calculated the annual percent change (APC) in incidence using the Joinpoint Regression Program and conducted an age-period-cohort analysis of elderly glioblastoma reported between 2000 and 2017 to the Surveillance Epidemiology and End Results (SEER) 18 registry database.

Results

The overall incidence rate of elderly patients with glioblastoma was 13.16 per 100,000 (95% CI, 12.99–13.32) from 2000 to 2017. Non-Hispanic whites (20,406, 83.6%) made up the majority. The incidence rate of male was about 1.62 times that of female. The trend of incidence remained stable and there was a non-significant increasing tendency for all elderly patients (APC 0.3, 95% CI, − 0.1 to 0.7, p = 0.111). There was a significantly increasing incidence trend for non-Hispanic white (APC 0.6, 95% CI, 0.2 to 1.1, p = 0.013), supratentorial location (APC 0.7, 95% CI, 0.2 to 1.3, p = 0.016), tumor size < 4 cm (APC 2.5, 95% CI, 1.4 to 3.6, p < 0.001), and a significantly decreasing trend for overlapping/NOS location (APC -0.9, 95% CI, − 1.6 to − 0.2, p = 0.012), and unknown tumor size (APC -4.9, 95% CI, − 6.6 to − 3.3, p < 0.001). The age-period-cohort analysis showed the effect of age on incidence trends (p< 0.001, Wald test), while did not indicate the period and cohort effects of the incidence trends of glioblastoma (p = 0.063 and p =0.536, respectively, Wald test).

Conclusion

The overall incidence of glioblastoma in the elderly population remained stable between 2000 and 2017. Period and cohort effects were not evident in the trend of glioblastoma incidence. Future population-based studies exploring the difference in the trend of glioblastoma incidence by specific molecular subgroups are warranted to further our understanding of the etiology of glioblastoma.

Age, Period and Cohort Analysis of Smoking Prevalence in Iranian Population over a 25-Year Period

BACKGROUND

Current and daily smoking prevalence rates have been have investigated in several cross-sectional studies. However, analyses in terms of age-period-cohort (APC) have not been carried out. We assessed daily smoking dynamics over a 25-year period using the APC model.

METHODS

In our analyses, we used data from 214,652 people aged 15 to 64 years, collected by national health surveys conducted in 1990-1991, 1999, 2005, 2007, 2011 and 2016. The Intrinsic Estimator model was used to analyze the impact of APC on daily smoking prevalence.

RESULTS

Males were found to exhibit a higher prevalence of smoking compared to females (26.0% against 2.7%). Prevalence of smoking increased by age, peaking at the age groups of 40-44 in men and 45-49 in women, followed by a decreasing trend. The 1990 period had the highest prevalence in both genders, and the 2016 period had the lowest. The coefficients of birth cohort effects showed different patter19s of fluctuations in the two genders with the maximum and minimum coefficients for men calculated in the 1966-1970 and 1991-95 birth cohorts, and for females the 1931-1935 and 1971-1975 birth cohorts, respectively.

CONCLUSION

We showed the impact of APC on daily tobacco smoking prevalence, and these factors should be considered when dealing with smoking.

Increasing trends in incidence of preterm birth among 2.5 million newborns in Guangzhou, China, 2001 to 2016: an age-period-cohort analysis

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.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12889-020-09739-6.

Worldwide trends in breast cancer incidence from 1993 to 2012: Age-period-cohort analysis and joinpoint regression

Background:

Breast cancer is the most common cancer accounting for about one-fourth of total cancer cases and 15% of all cancer deaths among women worldwide. It is important to determine its trend across the regions in the world to find the high-focus regions. Hence, the current study was done to assess the global trends and deviations in the incidence of breast cancer.

Materials and Methods:

A descriptive trend analysis was done using the data on breast cancer incidence from the WHO Cancer Incidence Data of Five Continents plus database. Joinpoint regression was performed to determine the average annual percent change (AAPC), and age-period-cohort analysis was done to obtain age-, period-, and cohort-specific deviations and rate ratio.

Results:

All the regions showed an increasing trend in breast cancer incidence, with an exception of America. Maximum increase was observed in Asia (AAPC = 2.6%; 95% confidence interval [CI]: 2.4%–2.9%) followed by Europe (AAPC = 0.7%; 95% CI: 0.5%–1%). There was consistent rise in the breast cancer incidence across the age groups in all the four continents with maximum burden in elderly (P < 0.001). Except in America, all other regions showed consistent rise in the incidence of breast cancer through the periods 1998–2002 to 2007–2012 (P < 0.001). There was consistent increase across the cohorts from 1923–1927 to 1978–1982 in continents such as Asia and Oceania (P < 0.001).

Conclusion:

To summarize, the incidence of breast cancer shows an increasing trend globally with a maximum increase in the Asian region. This makes a strong need for newer strategies irrespective of current prevention and control interventions.

Suicide mortality in Spain (1984-2018): age-period-cohort analysis

OBJECTIVE

To assess the effects of age, period and cohort suicide mortality trend in Spain (1984-2018).

METHODS

Mortality and population data were obtained from the National Institute of Statistics. The analysis of the effect of age, period of death and birth cohort on the evolution of suicide mortality in the period 1984-2018 was performed using a web tool for age-period-cohort analysis provided by the Division of Cancer Epidemiology and Genetics of the National Cancer Institute of the USA.

RESULTS

Rates increase with age (age effect) in both sexes. The period effect shows, in males, an increase over the period 1984-1998 followed by a significant decrease until 2018. In females, rates remain stable over the period 1987-2002, decrease during 2007-2012 (p < 0.05) and eventually stabilise. In both males and females, the risk decreases in each successive birth cohort between 1904 and 1939. Subsequently, the risks increase until the birth cohort of the period 1964-1974 after which the risk decreases for males and remains stable for females.

CONCLUSION

A better understanding of the effects of the birth cohort could open new doors in suicide prevention.

A cross country comparison for the burden of cardiovascular disease attributable to tobacco exposure in China, Japan, USA and world

BACKGROUND

Tobacco exposure (TE) is the major contributor for CVD mortality, but few published studies on CVD mortality attributable to TE have analyzed the potential reasons underlying long-term trends in China. Our studysought to find the potential reasons and compared CVD mortality attributable to TE in China, Japan, the United States of America (USA), and the world between 1990 and 2017.

METHODS

The mortality data in China, Japan, the USA, and the world were obtained from Global Burden of Disease Study 2017(GBD 2017). Joinpoint regression was used to assess the trend magnitude and directions over time for CVD mortality, while the age-period-cohort method was used to analyzethe temporal trends of CVD mortality according to age, period, and cohort.

RESULTS

A significant downward trend was found in the age-standardised mortality rate (ASMR) of CVD attributable to smoking in four regions. China had the smallest decline and the Chinese ASMR became the highest in 2017. All the annual net drifts in the four regions were negative and the local drifts were below zero. The longitudinal age curves of CVD mortality attributable to smoking increased in four regions,with China having the largest increase. The period or cohort RRs indicated a decline, and China had the smallest decline. The researchers further analyzed the IHD and stroke trends, finding that the morality and period or cohort RR of IHD in China was always at a high level.

CONCLUSIONS

CVD mortality attributable to TE declined in four regions, and was highest in China. The proportion of IHD mortality attributable to TE was similar to stroke, which significantly changed the traditional cognition of CVD composition, but the control measure was not sufficient for IHD in China.

Age-period-cohort effects in pre-existing and pregnancy-associated diseases amongst primiparous women

BACKGROUND

The average age at first birth is steadily increasing in developed countries; however, demographic shifts in maternal age at childbearing have not occurred in isolation. While temporal increases in adverse pregnancy outcomes are typically attributed to increases in maternal age, little is known about how maternal health status has changed across maternal age, period of delivery, and birth cohort.

METHODS

Natality files were used to identify primiparous women delivering liveborn, singleton infants in the USA in 1989, 1994, 1999, 2004, 2009, and 2014 (n = 6,857,185). Age-period-cohort models using the intrinsic estimator adjusted for temporal trends in smoking and gestational weight gain were used to quantify temporal changes in the rates of pre-existing (chronic hypertension, pre-existing diabetes) and pregnancy-associated (pregnancy-associated hypertension, gestational diabetes, eclampsia) diseases. Log-linear models were used to model the impact of temporal changes on preterm birth, small, and large for gestational age (SGA/LGA) births.

RESULTS

Significant period effects resulted in temporal increases in the rate of chronic hypertension, pregnancy-associated hypertension, and gestational diabetes, and a significant decrease in the rate of eclampsia. These observed period effects were associated with a 10.6% increase in the rate of SGA and a 7.1% decrease in LGA. Had the rate of pre-existing and pregnancy-associated diseases remained static over this time period, the rate of preterm birth would have increased by 5.9%, but instead only increased by 4.4%.

CONCLUSIONS

Independent of changes in the incidence of pre-existing and pregnancy-associated diseases as women age, the obstetric population is becoming less healthy over time. This is important, as these changes have a direct negative impact on short-term obstetric outcomes and women's long-term health.

Age-Period-Cohort Analysis of Type-Specific Stroke Morbidity and Mortality in China

BACKGROUND

Stroke has become the leading cause of death in China. This study aimed to assess the age-period-cohort (APC) effects on the long-term trends of type-specific stroke morbidity and mortality in China between 1993 and 2017.Methods and Results:The data were obtained from the Global Burden of Disease 2017 (GBD 2017) and were analyzed with the age-period-cohort framework. The net drifts of mortality were below 0 (hemorrhagic stroke [HS]: males: -1.620%, females: -3.531%; ischemic stroke [IS]: males: -1.041%, females: -3.002%), and the local drift values were below 0 in all age groups and for both genders. The net drifts of HS incidence were below 0 (males: -1.412%, females: -2.688%), while those of IS were above 0 (males: 1.425%, females: 1.117%). Period effect of mortality showed similar monotonic downward patterns for both genders, with a faster decrease for females than for males. Period effect of incidence showed a declined trend of incidence for HS, but an elevated trend for IS in both genders. After controlling for age and period effects, cohort effects on incidence found a monotonic decline trend for HS, while for IS, an elevated trend was found at first to peak during the 1950-1970 s, then declined steadily afterwards. Cohort effects on mortality showed a monotonic declined trend.

CONCLUSIONS

By using Age-Period-Cohort (APC) analysis, a disparity between HS and IS was identified. Different prevention and control strategies should be used depending on the subtypes of stroke.

Trends in mortality from road traffic injuries in South Korea, 1983-2017: Joinpoint regression and age-period-cohort analyses

Although mortality trends can be influenced by different ages, periods, and cohorts, few studies have demonstrated the age-period-cohort (APC) effect on road traffic injury (RTI) mortality. Moreover, APC effects in Korea have never been documented despite the high mortality rates from RTIs. This study aimed to describe the trends in mortality from RTIs and examine APC effects on RTI mortality in Korea. Using the national death certificate and census mid-year population estimates data during 1983-2017, trends in age-standardized mortality rates from RTIs were analyzed using Joinpoint regression. Intrinsic estimator regression models were used to estimate APC effects on RTI mortality. Consistent with the trend in period effects, RTI mortality increased sharply with the economic growth in the 1980s, decelerated after the implementation of road safety policies in the early 1990s, plummeted owing to the 1997-1998 financial crisis, and gradually decreased from the early 2000s. A J-shaped age effect indicated that the relative risk of road traffic death surged in people aged ≥65 years. Educational expansion from the mid-1950s turned an increasing birth cohort effect into a continuously decreasing trend after peaking around the 1938-1943 birth cohorts. The risk of road traffic death was relatively high among the Korean Generation Y, i.e., those born in 1978-1983. RTI mortality trends in Korea have been affected by diverse socioeconomic changes through cohort and period effects. Despite the recent favorable trend, RTI mortality remains high, especially among older people. Road safety policies to address the burden of RTIs require further improvement.

Gender differential secular trend in lifetime smoking prevalence among adolescents: an age-period-cohort analysis

Background

There has been a gender difference in adolescents’ lifetime smoking prevalence trends over the last 10 years. This study aimed to explain the gender differential secular trend in adolescents’ lifetime smoking prevalence using age-period-cohort (APC) analysis and suggests possible causes for this trend, including Korean tobacco control policies during the last 10 years.

Methods

We utilized the 2006–2017 Korea Youth Risk Behavior Web-based Survey enrolling grades 7 to 12. Using year of survey and year of entry into middle school, we classified 859,814 students who had ever smoked into 6 age groups, 12 periods, and 17 school admission cohorts. Using APC analysis with the intrinsic estimator method, the effects of age, period, and school admission cohort on lifetime smoking prevalence were analyzed according to gender.

Results

Overall, there was a similar tendency of all the three effects on lifetime smoking prevalence between genders: an increasing age effect with grade, negative period effect with survey period, and similar pattern of school admission cohort groups. However, compared to boys, girls experienced reduction in the increasing age effect in the 12th grade, consistent and steeper decreasing trend in the period effect from 2006 to 2016, and shorter and lower school admission cohort effect.

Conclusions

Gender differential response to chronological changes in lifetime smoking prevalence was measured by the APC effect, which affected the gender differential secular trend in lifetime smoking prevalence. Therefore, considering the APC effect could help us understand the trend in smoking rates, as well as the contextual factors that affect it.

Determinants of Influenza Mortality Trends: Age-Period-Cohort Analysis of Influenza Mortality in the United States, 1959-2016

This study examines the roles of age, period, and cohort in influenza mortality trends over the years 1959-2016 in the United States. First, we use Lexis surfaces based on Serfling models to highlight influenza mortality patterns as well as to identify lingering effects of early-life exposure to specific influenza virus subtypes (e.g., H1N1, H3N2). Second, we use age-period-cohort (APC) methods to explore APC linear trends and identify changes in the slope of these trends (contrasts). Our analyses reveal a series of breakpoints where the magnitude and direction of birth cohort trends significantly change, mostly corresponding to years in which important antigenic drifts or shifts took place (i.e., 1947, 1957, 1968, and 1978). Whereas child, youth, and adult influenza mortality appear to be influenced by a combination of cohort- and period-specific factors, reflecting the interaction between the antigenic experience of the population and the evolution of the influenza virus itself, mortality patterns of the elderly appear to be molded by broader cohort factors. The latter would reflect the processes of physiological capital improvement in successive birth cohorts through secular changes in early-life conditions. Antigenic imprinting, cohort morbidity phenotype, and other mechanisms that can generate the observed cohort effects, including the baby boom, are discussed.

Temporal heterogeneity of the association between social capital and health: an age-period-cohort analysis in China

OBJECTIVES

The temporal heterogeneity of the association between social capital and health has not been fully discussed yet, so this study aimed to examine whether and how the association between social capital and health varied with age, period, and cohort.

STUDY DESIGN

Data were taken from the Chinese General Social Survey of 2005 and 2015, with 15,488 samples being collected.

METHODS

An ordinary least square model with interaction terms was used to examine the age, period, and cohort variations in the association between bonding/bridging social capital and self-rated health/depression from the perspective of urban-rural comparison.

RESULTS

In urban China, the association between bonding social capital and self-rated health varied with age, the association between bonding social capital and depression varied with age and cohort, the association between bridging social capital and self-rated health varied with period, and the association between bridging social capital and depression varied with period and cohort. By contrast, in rural China, only the association between bonding social capital and self-rated health varied with period and the association between bridging social capital and depression varied with cohort.

CONCLUSIONS

This study extends the traditional perspective of social capital and health study, and the results indicate that we should not only examine the association between social capital and health from the perspective of urban-rural comparison but also consider the impacts of life course and social development on this association. In this sense, specific interventions should be taken to improve social capital and health.

How older people became less afraid of crime-An age-period-cohort analysis using repeated cross-sectional survey data

One of the most robust predictors of fear of crime is age: Older people tend to be more fearful. Yet, many questions beyond the basic cross-sectional relationship remain unexplored. We investigate cohort effects on fear of crime, applying graphical analyses and a version of the hierarchical age-period-cohort (HAPC) analysis to eight waves of the German subset of the European Social Survey. We hypothesize that health improvements and the educational expansion in postwar Germany led to a decreasing cohort trend, and that children exposed to traumatic experiences and adverse living conditions during and after World War II report higher levels of perceived insecurity throughout the life course. We argue that cross-sectional age differences are, in fact, to a large extent cohort effects, mediated by improved self-rated health and increasing education. The analyses also unveil a recent period effect after 2014. These novel findings add considerably to the understanding of the temporal dynamics of fear of crime.

Women's role in the rise in drinking in Australia 1950-80: an age-period-cohort analysis of data from the Melbourne Collaborative Cohort Study

BACKGROUND AND AIMS

In Australia, as in many countries, alcohol consumption increased dramatically during the second half of the 20th century, with increased availability of alcohol, relaxation of attitudes towards drinking and shifting roles and opportunities for women as facilitating factors. We sought to investigate drinking trends by gender and birth cohort in Australia during this period.

DESIGN

Retrospective cohort study.

SETTING, PARTICIPANTS AND MEASUREMENTS

Using the usual frequency and quantity of beverage-specific alcohol intake for 10-year periods from age 20, reported retrospectively from 40 789 participants aged 40-69 years (born 1920-49) at recruitment to the Melbourne Collaborative Cohort Study in 1990-94, we compared trends in alcohol consumption by sex in Australia between 1950 and 1990. Participants' average daily consumption for age decades were transformed to estimated intakes for 1950, 1960, 1970, 1980 and 1990.

FINDINGS

Alcohol consumption was higher for men than women during each decade. Alcohol consumption increased for both sexes in the 1950s, 1960s and 1970s, and fell after 1980. The rise before 1980 was roughly equal in absolute terms for both sexes, but much greater relative to 1950 for women. Women born during 1930-39 and 1940-49 drank more alcohol during early-middle adulthood (ages 20-40) than women born during 1920-29. In the 1980s, the fall was greater in absolute terms for men, but roughly equal relative to 1950 for both sexes. In both sexes, the decline in drinking in the 1980s for birth-decade cohorts was roughly in parallel.

CONCLUSIONS

Specific birth cohorts were influential in the rise in alcohol consumption by Australian women born in 1920-49 after World War II. Much of the convergence with men's drinking after 1980 reflects large reductions in drinking among men.

Long-term trends in pancreatic cancer mortality in Spain (1952-2012)

BACKGROUND

Pancreatic cancer is acquiring increasing prominence as a cause of cancer death in the population. The purpose of this study was to analyze long-term pancreatic cancer mortality trends in Spain and evaluate the independent effects of age, death period and birth cohort on these trends.

METHODS

Population and mortality data for the period 1952-2012 were obtained from the Spanish National Statistics Institute. Pancreatic cancer deaths were identified using the International Classification of Diseases ICD-6 to ICD-9 (157 code) and ICD-10 (C25 code). Age-specific and age-adjusted mortality rates were computed by sex, region and five-year period. Changes in pancreatic cancer mortality trends were evaluated using joinpoint regression analyses by sex and region. Age-period-cohort log-linear models were fitted separately for each sex, and segmented regression models were used to detect changes in period- and cohort-effect curvatures.

RESULTS

In men, rates increased by 4.1% per annum from 1975 until the mid-1980s and by 1.1% thereafter. In women, there was an increase of 3.6% per annum until the late 1980s, and 1.4% per annum from 1987 to 2012. With reference to the cohort effects, there was an increase in mortality until the generations born in the 1950s in men and a subsequent decline detected by the change point in 1960. A similar trend was observed in women, but the change point occurred 10 years later than in men.

CONCLUSIONS

Pancreatic cancer mortality increased over the study period in both sexes and all regions. An important rise in rates -around 4% annually- was registered until the 1980s, and upward trends were more moderate subsequently. The differences among sexes in trends in younger generations may be linked to different past prevalence of exposure to some risk factors, particularly tobacco, which underwent an earlier decrease in men than in women.

Trends in alcohol-related mortality in East and West Germany, 1980-2014: age, period and cohort variations

BACKGROUND AND AIMS

Several indicators suggest that the extent and trends of alcohol-related mortality differ between East and West Germany. Regional drinking patterns and differences in health-care systems are assumed to affect the risk of dying from an alcohol-induced disease. The study addresses two questions: (1) what are the unbiased and independent age, period and cohort effects on alcohol-related mortality trends in Germany; and (2) do these trends differ between East and West Germany?

METHODS

Data on alcohol-related mortality for East and West Germany came from the national causes of death register for the years 1980-2014. Analyses included all deaths fully attributable to alcohol based on the International Classification of Diseases (ICD-9 and ICD-10). Gender-stratified age-period-cohort analyses were conducted using the intrinsic estimator model.

RESULTS

Age effects showed a concave pattern with a peak at ages 55-64 years in both regions. Incidence rate ratios (IRR) in East Germany were highest in the years 1990-1994 (men and women: IRR = 1.52) and declined thereafter. In West Germany, IRR were lowest in 1980-1984 (men: IRR = 0.81, women: IRR = 0.75) and stabilized at approximately 1.10 since 1995-1999. Cohort effects showed continuously lower IRR for those born after 1955-1959 in the East and those born after 1945-1949 in the West. Patterns for males and females were comparable.

CONCLUSIONS

The results suggest that alcohol-related mortality showed different trends in East and West Germany, which can be explained partly by different drinking patterns before and changes in the health-care system after the reunification.

Cancer mortality in Serbia, 1991-2015: an age-period-cohort and joinpoint regression analysis

Background

As the result of dramatic political changes, civil wars, and a long-term refugee crisis from the end of the last to beginning of this century, the population of Serbia has experienced significant health problems. The aim of this study was to assess cancer mortality trends in Serbia.

Methods

This nationwide study was carried out to analyze cancer mortality in Serbia during 1991–2015 using official data. The age-standardized mortality rates (per 100,000) were calculated by direct standardization, using the world standard population by Segi. The average annual percent change (AAPC) and corresponding 95% confidence interval (CI) were computed using joinpoint regression analysis. Age-period-cohort analysis was performed to address the possible underlying reasons for the observed temporal trends.

Results

Over the 25-year study period, there were 466,075 cancer deaths (266,043 males and 200,032 females) in Serbia. Overall cancer mortality increased between 1991 and 2009 in both males (by + 0.9% per year) and females (by + 0.8% per year) and has been decreasing since then, by − 0.9% annually in both sexes. For almost all major cancers except stomach cancer, cancer mortality in Serbia demonstrated upward trends during the study period. The largest increases were noted in lung cancer among females (AAPC = + 3.7, 95% CI 3.5–3.9) and prostate cancer in males (AAPC = + 1.9, 95% CI 1.4–2.3).

Conclusions

After two decades of increase, cancer mortality rates are finally declining in Serbia. Despite this, these rates place Serbia among the countries with the highest cancer mortality in the world.

Three Dimensions of Change in School Segregation: A Grade-Period-Cohort Analysis

This study uses the first age-period-cohort (APC) analysis of segregation to examine changes in U.S. public school segregation from 1999-2000 to 2013-2014. APC analyses disentangle distinct sources of change in segregation, and they account for grade effects that could distort temporal trends if grade distributions change over time. Findings indicate that grade effects are substantial, drastically reducing segregation at the transition to middle school and further at the transition to high school. These grade effects do not substantially distort the analysis of recent trends, however, because grade distributions were sufficiently stable. Black-white segregation was stagnant overall, while Hispanic-white segregation declined modestly. In both cases, declines across periods were offset by increases across cohorts. Further analyses reveal variation in these trends across metropolitan and nonmetropolitan areas, regions, and areas with different histories of desegregation policy.