Models for temporal variation in cancer rates. II: Age-period-cohort models

Global, regional and national trends in the burden of low bone mineral density from 1990 to 2030: A Bayesian age-period-cohort modeling study

Low bone mineral density (LBMD) remains a global public health concern. To provide deeper insights, we retrieved and calibrated LBMD death and Disability-Adjusted Life Years (DALYs) data from the Global Burden of Disease 2021 (GBD 2021) database. We calculated the age-standardized rate (ASR) and estimated annual percentage change (EAPC) to delineate LBMD trends across sexes, age groups, Sociodemographic Index (SDI) regions, and countries. Spearman rank order correlation analysis was used to explore the relationship between SDI and ASR. Additionally, we constructed Bayesian age-period-cohort (BAPC) models to predict future trends in LBMD up to 2030, with the mean absolute percentage error (MAPE) used to evaluate prediction accuracy. Our analyses revealed that global deaths related to LBMD nearly doubled, from 250,930 in 1990 to 463,010 in 2021, and are projected to rise to 473,690 by 2030. However, the ASR exhibited an opposite trend, decreasing from 17.91 per 100,000 in 1990 to 15.77 per 100,000 in 2021, and is expected to further decline to 13.64 per 100,000 by 2030. The EAPC indicated descending trends in 1990-2021 and 2022-2030. Trends in LBMD varied across different subgroups by sex, age, and location. Males are projected to continue experiencing higher death numbers than females, though the gap is narrowing. The 90 to 94 age group consistently had the highest ASR from 1990 to 2030. Lower SDI remains a critical factor contributing to the higher burden of LBMD. Spearman rank order correlation analysis showed a negative correlation between SDI and ASR. We categorized 6 distinct trends in ASR across different countries, with most expected to experience a decline by 2030. The MAPE value (0.038 < 0.1) indicated that the BAPC model produced reliable predictions even under the COVID-19 pandemic.

All-cause, cardiovascular disease and cancer mortality in the population of a large Italian area contaminated by perfluoroalkyl and polyfluoroalkyl substances (1980-2018)

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are associated with many adverse health conditions. Among the main effects is carcinogenicity in humans, which deserves to be further clarified. An evident association has been reported for kidney cancer and testicular cancer. In 2013, a large episode of surface, ground and drinking water contamination with PFAS was uncovered in three provinces of the Veneto Region (northern Italy) involving 30 municipalities and a population of about 150,000. We report on the temporal evolution of all-cause mortality and selected cause-specific mortality by calendar period and birth cohort in the local population between 1980 and 2018.

METHODS

The Italian National Institute of Health pre-processed and made available anonymous data from the Italian National Institute of Statistics death certificate archives for residents of the provinces of Vicenza, Padua and Verona (males, n = 29,629; females, n = 29,518) who died between 1980 and 2018. Calendar period analysis was done by calculating standardised mortality ratios using the total population of the three provinces in the same calendar period as reference. The birth cohort analysis was performed using 20-84 years cumulative standardised mortality ratios. Exposure was defined as being resident in one of the 30 municipalities of the Red area, where the aqueduct supplying drinking water was fed by the contaminated groundwater.

RESULTS

During the 34 years between 1985 (assumed as beginning date of water contamination) and 2018 (last year of availability of cause-specific mortality data), in the resident population of the Red area we observed 51,621 deaths vs. 47,731 expected (age- and sex-SMR: 108; 90% CI: 107-109). We found evidence of raised mortality from cardiovascular disease (in particular, heart diseases and ischemic heart disease) and malignant neoplastic diseases, including kidney cancer and testicular cancer.

CONCLUSIONS

For the first time, an association of PFAS exposure with mortality from cardiovascular disease was formally demonstrated. The evidence regarding kidney cancer and testicular cancer is consistent with previously reported data.

Breast cancer incidence trends in Golestan, Iran: An age-period-cohort analysis by ethnic region, 2004-2018

BACKGROUND

We aimed to examine the effects of age, diagnosis year (calendar period) and birth year (cohort) on the incidence trends of breast cancer among Golestan women, Northeast Iran, 2004-2018.

METHODS

Incidence data were obtained by residential status (urban/rural) and ethnic region (Turkmens/non-Turkmens). We calculated age-standardized incidence rates (ASRs) per 100,000 person-years. The estimated annual percentage change (EAPC) were calculated, and age-period-cohort (APC) models fitted to assess non-linear effects of period and cohort as incidence rate ratios (IRRs).

RESULTS

The total number of female breast cancer cases in Golestan, 2004-2018, were 3853, with an overall ASR of 31.3. We found higher rates in urban population (40.5) and non-Turkmens region (38.5) compared to rural area (20.8) and Turkmens region (20.2), respectively. There were increasing trends in incidence rates overall (EAPC= 4.4; 95%CI: 2.2, 6.7), with greater changes in rural areas (EAPC=5.1), particularly among non-Turkmens (EAPC=5.8). The results of the APC analysis indicate the presence of significant non-linear cohort effects with increasing IRRs across successive birth cohorts (IRR=0.1 and IRR= 2.6 for the oldest and the youngest birth cohorts vs. the reference birth cohort, respectively).

CONCLUSION

We found increasing trends in breast cancer incidence among Golestan women over the study period, with disparities in patterns and trends by residence area and ethnic region. The observed cohort effects suggest an increasing prevalence of key risk factors for breast cancer in this Iranian population. Further investigations are warranted to clarify the relationships between determinants such as reproductive factors and ethnicity in the region.

Time trends in the burden of low back pain and its associated risk factors in China from 1990 to 2019

Background

From 1990 to 2019, low back pain (LBP) was the leading cause of years lived with disability (YLDs) in China. However, the change patterns of LBP and its risk factors in China remain unclear.

Methods

Data from the Global Burden of Disease Study 2019 were used. We used the join-point regression model and age-period-cohort analysis to evaluate the time trends of attributable risk factors on the burden of LBP.

Results

In 2019, the risk factors included in this analysis accounted for 4.36 million YLDs of LBP, representing 42.2% of all YLDs of LBP in China, with 2.86 million due to occupational ergonomic factors, 1.74 million due to smoking, and 0.46 million due to high body mass index (BMI). The age-standardized YLD rates of LBP showed downward trends during 1990-2019, while there was a faster decline between 1990 and 1994. The curves of local drifts, which reflected the average annual percentage change across age groups, showed an increasing trend with age for high BMI and smoking, and a downward trend for occupational ergonomic factors. The YLD rates for LBP increased dramatically with age for high BMI, while it reached a peak at 40-60 years old for occupational ergonomic factors, and 65-80 years old for smoking. The period and cohort rate ratios of LBP YLD decreased in the past 3 decades for occupational ergonomic factors and smoking, while increased for high BMI.

Conclusions

Our results provided strong evidence that there were diverse changing patterns for different risk factors, highlighting the need for risk-specific strategies.

The translational potential of this article

China has the largest senior population and the fastest aging population in the world. Given that LBP typically occurs in the senior population, there would be an increasing LBP burden on China's health system. This suggests that effective strategies for LBP prevention should be strictly implemented in China, particularly in the senior population, which is of crucial translational potential.

Multidimensional penalized splines for survival models: illustration for net survival trend analyses

BACKGROUND

In descriptive epidemiology, there are strong similarities between incidence and survival analyses. Because of the success of multidimensional penalized splines (MPSs) in incidence analysis, we propose in this pedagogical paper to show that MPSs are also very suitable for survival or net survival studies.

METHODS

The use of MPSs is illustrated in cancer epidemiology in the context of survival trends studies that require specific statistical modelling. We focus on two examples (cervical and colon cancers) using survival data from the French cancer registries (cases 1990-2015). The dynamic of the excess mortality hazard according to time since diagnosis was modelled using an MPS of time since diagnosis, age at diagnosis and year of diagnosis. Multidimensional splines bring the flexibility necessary to capture any trend patterns while penalization ensures selecting only the complexities necessary to describe the data.

RESULTS

For cervical cancer, the dynamic of the excess mortality hazard changed with the year of diagnosis in opposite ways according to age: this led to a net survival that improved in young women and worsened in older women. For colon cancer, regardless of age, excess mortality decreases with the year of diagnosis but this only concerns mortality at the start of follow-up.

CONCLUSIONS

MPSs make it possible to describe the dynamic of the mortality hazard and how this dynamic changes with the year of diagnosis, or more generally with any covariates of interest: this gives essential epidemiological insights for interpreting results. We use the R package survPen to do this type of analysis.

Advances in statistical methods for cancer surveillance research: an age-period-cohort perspective

Background

Analysis of Lexis diagrams (population-based cancer incidence and mortality rates indexed by age group and calendar period) requires specialized statistical methods. However, existing methods have limitations that can now be overcome using new approaches.

Methods

We assembled a "toolbox" of novel methods to identify trends and patterns by age group, calendar period, and birth cohort. We evaluated operating characteristics across 152 cancer incidence Lexis diagrams compiled from United States (US) Surveillance, Epidemiology and End Results Program data for 21 leading cancers in men and women in four race and ethnicity groups (the "cancer incidence panel").

Results

Nonparametric singular values adaptive kernel filtration (SIFT) decreased the estimated root mean squared error by 90% across the cancer incidence panel. A novel method for semi-parametric age-period-cohort analysis (SAGE) provided optimally smoothed estimates of age-period-cohort (APC) estimable functions and stabilized estimates of lack-of-fit (LOF). SAGE identified statistically significant birth cohort effects across the entire cancer panel; LOF had little impact. As illustrated for colon cancer, newly developed methods for comparative age-period-cohort analysis can elucidate cancer heterogeneity that would otherwise be difficult or impossible to discern using standard methods.

Conclusions

Cancer surveillance researchers can now identify fine-scale temporal signals with unprecedented accuracy and elucidate cancer heterogeneity with unprecedented specificity. Birth cohort effects are ubiquitous modulators of cancer incidence in the US. The novel methods described here can advance cancer surveillance research.

Incidence trends of primary liver cancer in different geographical regions of China from 1978 to 2012 and projections to 2032: An age-period-cohort analysis

China accounted for 45.3% of new cases of primary liver cancer (PLC) worldwide in 2020. While variations in PLC incidence between different regions of China and decreasing incidence in overall China have been reported, incidence patterns have not been thoroughly explored by region. We examined the nearly status and temporal trends of PLC incidence in different geographical regions in China and project future trends. The age-standardized incidence rate (ASR) was estimated for 1978 to 2012 by different geographical regions and gender in China. Age-period-cohort model was adopted to evaluate age and birth cohort effects on the temporal trend of five registries of China (Hong Kong, Shanghai, Jiashan, Harbin and Zhongshan), Bayesian age-period-cohort model was adopted to project future trends for 2013 to 2032. PLC incidence in China exhibits marked geographical disparity, with the highest incidence in Southwest China, and gender differences being particularly pronounced in South China. While other registries exhibited decreasing trend, Zhongshan exhibited an increasing trend, with the cohort effect showing a marked upward trend for females born in 1916 to 1949 and males born in 1916 to 1962. During 2013 to 2032, the ASR appears to increase by 86.9% for men and 40.0% for women in Zhongshan, while the remaining registries will decline by around 50%. Since the high incidence of hepatitis B virus infection in early birth cohort, recent rise of nonviral risk factors and the severe aging of the Chinese population, it may be critical to tailor future prevention and control strategies for PLC to the distribution of risk factors in different geographical regions.

Trends in Suicide Among Black Women in the United States, 1999-2020

Objective:

Recent increases in suicide deaths among Black women in the US warrant further investigation. Our objective was to clarify the epidemiology of suicide among Black girls and women, by estimating age-period-cohort effects on suicide rates among decedents coded as female aged 15-84 years.

Methods:

The present study examined annual time-series data from the National Center for Health Statistics’ Multiple Cause of Death 1999-2020 database. Suicide rates by age, period, and cohort were visualized using hexagonal maps, and estimated using modified Poisson regression to address identifiability.

Results:

In total, our analysis included 9,271 suicide deaths. Results indicated the presence of all three effects: (i) a clear age effect, with higher rates at younger ages, regardless of cohort and time, (ii) a period effect, with rates generally increasing across time for most ages, and (iii) a cohort effect, with a clustering of increased suicide rates among the youngest cohorts. Across regions, rates were highest among the youngest age groups, concentrated in the West.

Conclusion:

Suicide is increasing rapidly among Black females – with particularly concerning trends among the youngest Black females born in the most recent birth cohorts. Findings suggest a need for increased mental health access and geographically targeted prevention efforts.

Comparison of statistical models to predict age-standardized cancer incidence in Switzerland

This study compares the performance of statistical methods for predicting age-standardized cancer incidence, including Poisson generalized linear models, age-period-cohort (APC) and Bayesian age-period-cohort (BAPC) models, autoregressive integrated moving average (ARIMA) time series, and simple linear models. The methods are evaluated via leave-future-out cross-validation, and performance is assessed using the normalized root mean square error, interval score, and coverage of prediction intervals. Methods were applied to cancer incidence from the three Swiss cancer registries of Geneva, Neuchatel, and Vaud combined, considering the five most frequent cancer sites: breast, colorectal, lung, prostate, and skin melanoma and bringing all other sites together in a final group. Best overall performance was achieved by ARIMA models, followed by linear regression models. Prediction methods based on model selection using the Akaike information criterion resulted in overfitting. The widely used APC and BAPC models were found to be suboptimal for prediction, particularly in the case of a trend reversal in incidence, as it was observed for prostate cancer. In general, we do not recommend predicting cancer incidence for periods far into the future but rather updating predictions regularly.

Colorectal cancer incidence trends in Golestan, Iran: An age-period-cohort analysis 2004-2018

BACKGROUND

We investigated the effects of factors including age, birth year (cohort) and diagnosis year (period) on colorectal cancer (CRC) incidence trends in Golestan, Northeast of Iran, 2004-2018.

METHODS

We obtained data on incidence cases of CRC from the Golestan Population-based Cancer Registry by sex and area of residence (urban/rural). Age-standardized incidence rates (ASRs) were calculated using the World standard population and presented per 100,000 person-years. We calculated the estimated annual percentage change (EAPC) with 95 % confidence intervals (95 % CI) fitted age-period-cohort (APC) models to assess non-linear period and cohort effects as incidence rate ratios (IRRs).

RESULTS

Overall, 2839 new cases of CRC (ASR = 13.7) were registered in the GPCR over 2004-2018. Our findings suggested significantly increasing trends in CRC incidence rates from 2004 to 2018 (EAPC = 3.7; 95%CI: 0.4, 7.1), with the greatest changes occurring in rural women (EAPC= 4.7; 95%CI: 0.4, 9.2). We observed a strong cohort effect with a consistent increase in the IRR across successive birth cohorts, starting with the oldest birth cohort (1924) (IRR= 0.1 versus the reference birth cohort of 1955) through to the most recent cohort born in 1983 (IRR= 1.9). The largest cohort effects were found among rural females (IRR = 0.0, and IRR = 2.5 for the oldest and the youngest birth cohorts vs. the reference birth cohort, respectively).

CONCLUSION

The increasing trends in CRC rates in Golestan are largely driven by generational changes in exposure to underlying risk factors. Further investigations are warranted to deliver effective prevention strategies for the control of CRC in Golestan.

Backtesting stochastic mortality models by prediction interval-based metrics

Human lifespan increments represent one of the main current risks for governments and pension and health benefits providers. Longevity societies imply financial sustainability challenges to guarantee adequate socioeconomic conditions for all individuals for a longer period. Consequently, modelling population dynamics and projecting future longevity scenarios are vital tasks for policymakers. As an answer, the demographic and the actuarial literature have been introduced and compared to several stochastic mortality models, although few studies have thoroughly tested the uncertainty concerning mortality projections. Forecasting mortality uncertainty levels have a central role since they reveal the potential, unexpected longevity rise and the related economic impact. Therefore, the present study poses a methodological framework to backtest uncertainty in mortality projections by exploiting uncertainty metrics not yet adopted in mortality literature. Using the data from the Human Mortality Database of the male and female populations of five countries, we present some numerical applications to illustrate how the proposed criterion works. The results show that there is no mortality model overperforming the others in all cases, and the best model choice depends on the data considered.

Temporal trends in mortality of tuberculosis attributable to high fasting plasma glucose in China from 1990 to 2019: a joinpoint regression and age-period-cohort analysis

Background

Nowadays, high fasting plasma glucose (HFPG) has been identified as the important risk factor contributing to the increased burden of diseases. But there remains a lack of research on tuberculosis (TB) mortality specifically attributable to HFPG. Thus, this study aims to explore the long-term trends in HFPG-related TB mortality in China from 1990 to 2019.

Methods

Data on HFPG-related TB mortality were obtained from the Global Burden of Disease (GBD) Study 2019. Analyzing the data using joinpoint regression and age-period-cohort methods adjusting for age, period, and cohort allowed us to assess the trends in TB mortality due to HFPG.

Results

The age-standardized mortality rates (ASMRs) of TB attributable to HFPG exhibited a downward trend in China from 1990 to 2019, with an average annual percentage change (AAPC) of -7.0 (95% CI, -7.5 to -6.6). Similar trends were found for male (AAPC of -6.5 [95% CI, -7.0 to -6.0]) and female (AAPC of -8.2 [95% CI, -8.5 to -7.9]), respectively. Local drifts curve with a U-shaped pattern reflected the AAPC of TB mortality due to HFPG across age groups. The greatest decline was observed in the age group of 60-64 years. The mortality rates related to HFPG first increased and then decreased with increasing age, peaking in the 55-59 age group. Our analysis of the period and cohort effects found that the rate ratios of TB mortality due to HFPG have decreased over the past three decades, more prominently in women. It is noteworthy that while both genders have seen a decline in HFPG-attributable TB mortality and risk, men have a higher risk and slightly less significant decline than women.

Conclusion

The present study shows that HFPG-related ASMRs and risk of TB in China decreased over the last 30 years, with similar trends observed in both men and women. In order to attain the recommended level set by the WHO, the effective strategies for glycemic control and management still needed to be implemented strictly to further decrease the burden of TB.

Esophageal and gastric cancer incidence trends in Golestan, Iran: An age-period-cohort analysis 2004 to 2018

Golestan province in the northeast of Iran is part of the Asian esophageal cancer belt and is known as a high-risk area for esophageal (EC) and gastric cancers (GC). Data on incident cases of EC and GC during 2004 to 2018 were obtained from the Golestan Population-based Cancer Registry (GPCR). The age-standardized incidence rates (ASRs) were calculated and presented per 100 000 person-years. The estimated annual percentage change (EAPC) with 95% confidence interval (95% CI) were calculated. We also fitted age-period-cohort (APC) models to assess nonlinear period and cohort effects as incidence rate ratios (IRRs). Overall, 3004 new cases of EC (ASR = 15.7) and 3553 cases of GC (ASR = 18.3) were registered in the GPCR. We found significant decreasing trends in incidence rates of EC (EAPC = -5.0; 95% CI: -7.8 to -2.2) and less marked nonsignificant trends for GC (EAPC = -1.4; 95% CI: -4.0 to 1.4) during 2004 to 2018. There was a strong cohort effect for EC with a consistent decrease in the IRR across successive birth cohorts, starting with the oldest birth cohort (1924; IRR = 1.9 vs the reference birth cohort of 1947) through to the most recent cohort born in 1988 (IRR = 0.1). The marked declines in EC incidence rates in Golestan relate to generational changes in its underlying risk factors. Despite favorable trends, this population remains at high risk of both EC and GC. Further studies are warranted to measure the impact of the major risk factors on incidence with a view to designing effective preventative programs.

Stomach cancer incidence trends in selected Latin America countries: Age, period, and birth-cohort effects

BACKGROUND

to explore the age, period, and birth-cohort effects on stomach cancer incidence trends during 3 decades in selected Latin American countries.

METHODS

a time-trend study was performed using Cancer Incidence in Five Continents data from high-quality population-based cancer registries(PBCRs) in Latin American countries. Crude and age-standardized incidence rates(ASRIs) were calculated. Time trends in ASRIs were assessed using the average annual percentage change(AAPC). Age-period-cohort effects were estimated by Poisson regression for individuals aged between 20 and 79 years with stomach cancer informed by PBCRs from 1983 to 2012 in Cali(Colombia); from 1982 to 2011 in Costa Rica; and from 1988 to 2012 for Goiania(Brazil) and Quito(Ecuador). The goodness-of-fit model was tested using the deviance of the models.

RESULTS

a decrease in age-standardized incidence rates was observed for both genders in all populations covered by PBCRs, except for young men from Cali(AAPC 3.89 95 %IC: 1.32-7.29). The age effect was statistically significant in all areas, and the curve slope reached peaks in the older age groups. The cohort effect was observed in all PBCRs. Regarding the period effect, an increased ratio rate was observed for both genders in Costa Rica(1997-2001 women RR 1.11 95 %CI: 1.05-1.17; men RR 1.12 95 %CI: 1.08-1.17) and Goiânia(2003-2007 women RR 1.21 95 %CI: 1.08-1.35; men RR 1.09 95 %CI: 1.01-1.20), while Quito(1998-2002 women RR 0.89 95 %CI: 0.81-0.98; men RR 0.86 95 %CI: 0.79-0.93) presented a decrease.

CONCLUSION

the present study showed a decreasing gastric cancer trend for over the past 30 years with gender and geographic variations. Such a decrease seems to be mainly a result of cohort effects, suggesting that the economic market opening process led to changes in the risk factor exposures over successive generations. These geographic and gender variations may reflect cultural/ethnic/gender differences and differences in dietary and smoking rate patterns. However, an increased incidence was observed for young men in Cali, and additional studies are needed to determine the cause of the increasing incidence in this group.

Breast cancer epidemiology and sociodemographic differences in BRICS-plus countries from 1990 to 2019: An age period cohort analysis

Background

Breast cancer (BC) is a major health concern in the BRICS-plus, a group of developing nations consisting of Brazil, Russia, India, China, South Africa, and 30 other Asian countries, with nearly half of the world's population. This study aims to identify potential risk factors contributing to the burden of BC by assessing its epidemiological and socio-demographic changes.

Methods

Data on BC outcomes were obtained from the 2019 Global Burden of Disease Survey. The age-period-cohort (APC) modeling technique was used to evaluate the nonlinear impacts of age, cohort, and period on BC outcomes and reported risk attributable mortality and disability adjusted life years (DALYs) rate changes between 1990 and 2019.

Results

In 2019, there were 0.90 million female BC cases and 0.35 million deaths in the BRICS-plus region, with China and India having the largest proportion of incident cases and deaths, followed by Pakistan. Lesotho experienced the highest annualized rates of change (AROC: 2.61%; 95%UI: 1.99-2.99) in the past three decades. Birth cohorts' impact on BC varies greatly between the BRICS-plus nations, with Pakistan suffering the largest risk increase in the most recent cohort. High body mass index (BMI), high fasting plasma glucose (FPG), and a diet high in red meat contributed to the highest death and DALYs rates in most BRICS-plus nations in 2019, and there was a strong negative link between SDI and death and DALYs rate.

Conclusions

The study found that the burden of BC varies significantly between BRICS-plus regions. Thus, BRICS-plus nations should prioritise BC prevention, raise public awareness, and implement screening efficiency measures to reduce the burden of BC in the future, as well as strengthen public health policies and initiatives for important populations based on their characteristics and adaptability.

Widening educational inequalities in mortality in more recent birth cohorts: a study of 14 European countries

BACKGROUND

Studies of period changes in educational inequalities in mortality have shown important changes over time. It is unknown whether a birth cohort perspective paints the same picture. We compared changes in inequalities in mortality between a period and cohort perspective and explored mortality trends among low-educated and high-educated birth cohorts.

DATA AND METHODS

In 14 European countries, we collected and harmonised all-cause and cause-specific mortality data by education for adults aged 30-79 years in the period 1971-2015. Data reordered by birth cohort cover persons born between 1902 and 1976. Using direct standardisation, we calculated comparative mortality figures and resulting absolute and relative inequalities in mortality between low educated and high educated by birth cohort, sex and period.

RESULTS

Using a period perspective, absolute educational inequalities in mortality were generally stable or declining, and relative inequalities were mostly increasing. Using a cohort perspective, both absolute and relative inequalities increased in recent birth cohorts in several countries, especially among women. Mortality generally decreased across successive birth cohorts among the high educated, driven by mortality decreases from all causes, with the strongest reductions for cardiovascular disease mortality. Among the low educated, mortality stabilised or increased in cohorts born since the 1930s in particular for mortality from cardiovascular diseases, lung cancer, chronic obstructive pulmonary disease and alcohol-related causes.

CONCLUSIONS

Trends in mortality inequalities by birth cohort are less favourable than by calendar period. In many European countries, trends among more recently born generations are worrying. If current trends among younger birth cohorts persist, educational inequalities in mortality may further widen.

Use of 2-Stage Modeling to Identify How Colorectal Cancer Risk Changes With Period and Cohort

Colorectal cancer (CRC) incidence rates have decreased among adults aged 50 years or older while increasing in adults under age 50 years. Understanding these trends is challenging because of the multiple related time scales of age, diagnosis period, and birth cohort. We analyzed incidence rates of rectal, distal colon, and proximal colon cancer for individuals aged 20 years or more from the Surveillance, Epidemiology, and End Results Program for diagnosis years 1978-2017. We used a 2-stage generalized linear model to determine age, period, and cohort effects for CRC incidence. We first estimated birth cohort effects among people under age 45 years. We used these results to specify prior distributions for cohort effects in a Bayesian model to estimate period effects among people aged 45 years or more. There was no evidence of period effects for people under age 45 years. Risks of rectal and distal colon cancer increased for later birth cohorts. Compared with the 1943-1952 birth cohort, the 1983-1992 birth cohort had 2.2 times the risk of rectal cancer, 1.9 times the risk of distal colon cancer, and 1.3 times the risk of proximal colon cancer. For people aged ≥45 years, period effects showed declines in CRC risk that were attributable to screening.

Impact of human papillomavirus vaccine on cervical cancer epidemic: Evidence from the surveillance, epidemiology, and end results program

Introduction

Since 2006, the human papillomavirus (HPV) vaccine has been recommended for females aged 9-26 years in the United States. Aiming to evaluate the early effect of the HPV vaccine on cervical cancer, this study assessed the incidence of cervical cancer by age and histology before and after the introduction of HPV vaccination.

Methods

Data on cervical cancer incidence from 1975-2019 were extracted from the Surveillance, Epidemiology, and End Results Program. Joinpoint regression was used to determine temporal trends over time. Future cervical cancer incidence (2015-2039) was projected using Bayesian age-period-cohort analysis. Age-period-cohort (APC) models were created to evaluate age, period, and cohort effects.

Results

For overall cervical cancer and cervical squamous cell carcinoma (SCC), incidence rate showed decreasing trends (-0.7%, and -1.0% annually, respectively), whereas cervical adenocarcinoma (AC) incidence continuously increased (2.6% annually). The incidence trends for AC were stable in the 20-24 and 25-29-year age groups, whereas there was an increasing trend in older age groups. Similarly, the projected trend for AC in females aged 20-30 years exhibited a decline, whereas an increase was predicted in the 31-40-year age group, especially in the 35-44 year age group. The birth cohort and period effects in SCC and AC were extracted from APC models.

Discussion

During the period of 1975-2019, the incidence of cervical AC remained almost unchanged in the age groups receiving HPV vaccines while increased in the age groups not receiving HPV vaccines. The birth cohort effects of SCC and AC of the cervix provided evidence supporting the effectiveness of the HPV vaccine in preventing cervical cancer.

Trends in gestational diabetes mellitus among nulliparous pregnant individuals with singleton live births in the United States between 2011 to 2019: an age-period-cohort analysis

BACKGROUND

The rate of gestational diabetes mellitus has increased over the past decade. An age, period, and cohort epidemiologic analysis can be used to understand how and why disease trends have changed over time.

OBJECTIVE

This study aimed to estimate the associations of age (at delivery), period (delivery year), and cohort (birth year) of the pregnant individual with trends in the incidence of gestational diabetes mellitus in the United States.

STUDY DESIGN

We conducted an age, period, and cohort analysis of nulliparous pregnant adults aged 18 to 44 years with singleton live births from the National Vital Statistics System from 2011 to 2019. Generalized linear mixed models were used to calculate the adjusted rate ratios for the incidence of gestational diabetes mellitus for each 3-year maternal age span, period, and cohort group compared with the reference group for each. We repeated the analyses with stratification according to self-reported racial and ethnic group (non-Hispanic Asian-Pacific Islander, non-Hispanic Black, Hispanic, and non-Hispanic White) because of differences in the incidence of and risk factors for gestational diabetes mellitus by race and ethnicity.

RESULTS

Among 11,897,766 pregnant individuals, 5.2% had gestational diabetes mellitus. The incidence of gestational diabetes mellitus was higher with increasing 3-year maternal age span, among those in the more recent delivery period, and among the younger birth cohort. For example, individuals aged 42 to 44 years at delivery had a 5-fold higher risk for gestational diabetes mellitus than those aged 18 to 20 years (adjusted rate ratio, 5.57; 95% confidence interval, 5.43-5.72) after adjusting for cohort and period. Individuals who delivered between 2017 and 2019 were at higher risk for gestational diabetes mellitus than those who delivered between 2011 and 2013 (adjusted rate ratio, 1.24; 95% confidence interval, 1.23-1.25) after adjusting for age and cohort. Individuals born between 1999 and 2001 had a 3-fold higher risk for gestational diabetes mellitus than those born between 1969 and 1971 (adjusted rate ratio, 3.12; 95% confidence interval, 2.87-3.39) after adjusting for age and period. Similar age, period, and cohort effects were observed for the assessed racial and ethnic groups, with the greatest period effects observed among Asian and Pacific Islander individuals.

CONCLUSION

Period and birth cohort effects have contributed to the rising incidence of gestational diabetes mellitus in the United States from 2011 to 2019.

Trends in Liver Cancer Incidence and Survival in Italy by Histologic Type, 2003-2017

(1) Background: Liver cancer in Italy is characterised by one of the highest incidence rates worldwide outside of Asia coupled with comparatively favourable survival figures. The objective of this study was to evaluate the most recent epidemiologic trends of the disease. (2) Methods: Thirteen cancer registries covering a population of about 12,740,000 (21% of the national population) made available the records of 35,574 cases registered between 2003 and 2017. Trends in age-standardised (Europe 2013) incidence rates were analysed using the results of age-drift models. Trends in survival were analysed using 1-year, 2-year, 5-year and 10-year net survival (NS) and 5|1-year and 5|2-year conditional NS. (3) Results: Over the study period, the average annual incidence rates per 100,000 persons were 29.4 (men) and 9.4 (women) for total liver cancer; 14.6 and 3.5 for hepatocellular carcinoma (HCC); 1.8 and 1.1 for intrahepatic cholangiocarcinoma (ICC); and 13.0 and 4.8 for the 'other liver cancer types' group. The incidence of total liver cancer and HCC decreased significantly for both sexes. For total liver cancer, the estimated average annual percent change was -1.6% among men and -2.1% among women. For HCC, the change was -1.3% among men and -2.7% among women. ICC followed an opposite trend. For men, the risk of HCC had two peaks, one in the birth cohorts of 1928 and 1933 and another, more moderate peak in the cohort of 1958. Men and women exhibited comparable improvements in both early and mid-term conditional NS from HCC. In 2013-2017, 5-year NS was 28.9% (95% CI: 27.3%; 30.6%) for men and 30.1% (95% CI: 26.9%; 33.5%) for women. The uptrend in survival from ICC was less pronounced and was weakly significant, with a 5-year NS in 2013-2017 of 13.9% (95% CI: 10.8%; 17.3%) for men and 17.4% (95% CI: 13.5%; 21.7%) for women. (4) Conclusions: The opposite incidence trends of HCC and ICC confirm a pattern observed in other populations. The generalised, albeit slow, improvement in survival from HCC indicates a trend towards earlier detection coupled with improvements in treatments.

Long-Term Projections of Cancer Incidence and Mortality in Japan and Decomposition Analysis of Changes in Cancer Burden, 2020-2054: An Empirical Validation Approach

PURPOSE

The aim of this study was to project new cancer cases/deaths forward to 2054, and decompose changes in cancer cases/deaths to assess the impact of demographic transitions on cancer burden.

METHODS

We collected data on cancer cases/deaths up to 2019, empirically validated the projection performance of multiple statistical models, and selected optimal models by applying time series cross-validation.

RESULTS

We showed an increasing number of new cancer cases but decreasing number of cancer deaths in both genders, with a large burden attributed to population aging. We observed the increasing incidence rates in most cancer sites but reducing rates in some infection-associated cancers, including stomach and liver cancers. Colorectal and lung cancers were projected to remain as leading cancer burdens of both incidence and mortality in Japan over 2020-2054, while prostate and female breast cancers would be the leading incidence burdens among men and women, respectively.

CONCLUSIONS

Findings from decomposition analysis require more supportive interventions for reducing mortality and improving the quality of life of Japanese elders. We emphasize the important role of governments and policymakers in reforming policies for controlling cancer risk factors, including oncogenic infections. The rapid increase and continued presence of those cancer burdens associated with modifiable risk factors warrant greater efforts in cancer control programs, specifically in enhancing cancer screening and controlling cancer risk factors in Japan.

The comparative burden of brain and central nervous system cancers from 1990 to 2019 between China and the United States and predicting the future burden

Background

Brain and central nervous system (CNS) cancers represent a major source of cancer burden in China and the United States. Comparing the two countries' epidemiological features for brain and CNS cancers can help plan interventions and draw lessons.

Methods

Data were extracted from the Global Burden of Disease repository. The average annual percentage change (AAPC) and relative risks of cancer burdens were calculated using joinpoint regression analysis and age-period-cohort (APC) models, respectively. Moreover, a Bayesian APC model was employed to predict the disease burden over the next decade.

Results

From 1990 to 2019, the number of incidences, deaths, and disability-adjusted life-years (DALYs) increased in China and the US, with a larger increase in China. Age-standardized incidence rates in China and the United States have shown an increasing trend over the past three decades, with AAPCs of 0.84 and 0.16%, respectively. However, the rates of age-standardized mortality and age-standardized DALYs decreased in both countries, with a greater decrease in China. Overall, age trends in cancer burden were similar for males and females, with two peaks in the childhood and elderly groups, respectively. The period and cohort effects on incidence showed an overall increasing trend in China and limited change in the US. However, the period effects for mortality and DALY were decreasing in both countries, while the cohort effects tended to increase and then decrease. Moreover, we predicted that the cancer burdens would continue to rise in China over the next decade.

Conclusion

The burden of brain and CNS cancers is substantial and will continue to increase in China. Comprehensive policy and control measures need to be implemented to reduce the burden.

Secular trends in the epidemiologic patterns of peripheral artery disease and risk factors in China from 1990 to 2019: Findings from the global burden of disease study 2019

Background

An understanding of the epidemiologic patterns of peripheral artery disease is essential in public health policy-making. We aimed to assess secular trends in the epidemiologic patterns and risk factors of peripheral artery disease from 1990 to 2019 in China.

Materials and methods

We extracted data on prevalence, incidence, death, and disability-adjusted life years (DALYs) due to peripheral artery disease from the Global Burden of Disease study 2019. In addition, risk factors for peripheral artery disease were reported.

Results

The age-standardized prevalence of peripheral artery disease significantly increased from 1330.42 to 1423.78 per 100,000 population, with an average annual percentage change (AAPC) of 0.16 [95% confidence interval (CI), 0.07 to 0.24] from 1990 to 2019 in China. In addition, the age-standardized mortality rate significantly increased, with an AAPC of 0.62 (95% CI, 0.54 to 0.7), contrasting with the significantly declining trend in age-standardized DALYs (AAPC, −0.45; 95% CI, −0.52 to −0.39) between 1990 and 2019. The age-standardized prevalence was almost three times higher in females than males [2022.13 (95% CI: 1750 to 2309.13) vs. 744.96 (95% CI: 644.62 to 850.82) per 100,000 population] in 2019. The age-specific incidence significantly increased in individuals aged 40–44, 45–49, 50–54, 55–59, and 60–64 years groups but decreased in 70–74, 75–79, and 80–84 years groups. The age and period effects showed that the relative risks of incident peripheral artery disease increased with age and time. The cohort assessment showed that the incidence decreased in successive birth cohorts. Smoking was identified as the risk factor that contributed the most to age-standardized DALYs of peripheral artery disease in 2019.

Conclusion

The burden of peripheral artery disease showed unexpected patterns that varied by age, sex, and year in China. More attention should be given to addressing the increasing incidence among middle-aged individuals and mortality among males.

Racial Disparities in Spatial and Temporal Youth Suicide Clusters

OBJECTIVE

Deaths by suicide correlate both spatially and temporally, leading to suicide clusters. This study aimed to estimate racial patterns in suicide clusters since 2000.

METHOD

Data from the US National Vital Statistics System included all International Classification of Diseases, Tenth Revision (ICD-10)-coded suicide cases from 2000-2019 among American Indian/Alaska Native (AI/AN), Asian/Pacific Islander (A/PI), Black, or White youth and young adults, aged 5-34 years. We estimated age, period, and cohort (APC) trends and identified spatiotemporal clusters using the SaTScan space-time statistic, which identified lower- and higher-than-expected suicide rates (cold and hot clusters) in a prespecified area (150 km) and time interval (15 months). We also calculated the average proportion of deaths by suicide contained in clusters, to quantify the relative importance of spatiotemporal patterning as a driver of overall suicide rates.

RESULTS

From 2010-2019, suicide rates increased from between 37% among AI/AN (95% CI = 1.22, 1.55) to 81% among A/PI (95% CI = 1.65, 2.01) groups. Suicide clusters accounted for 0.8%-10.3% of all suicide deaths, across racial groups. Since 2000, the likelihood of detecting cluster increased over time, with considerable differences in the number of clusters in each racial group (4 among AI/AN to 72 among White youth). Among Black youth and young adults, 27 total clusters were identified. Hot clusters were concentrated in southeastern and mid-Atlantic counties.

CONCLUSION

Suicide rates and clusters in youth and young adults have increased in the past 2 decades, requiring attention from policy makers, clinicians, and caretakers. Racially distinct patterns highlight opportunities to tailor individual- and population-level prevention efforts to prevent suicide deaths in emerging high-risk groups.

Analysis of Rheumatic Heart Disease Mortality in the Chinese Population: A JoinPoint and Age-Period-Cohort Study

(1) Background: We aimed to analyze rheumatic heart disease (RHD) mortality trends in China's urban and rural areas and to determine the roles of age, period, and cohort effects. (2) Methods: Based on mortality data extracted from the China Health Statistics Yearbook, we calculated the crude mortality rate of RHD. Age-adjusted rates were computed by the direct method using the 2020 census as the standard population. The annual percentage change (APC) and average annual percentage change (AAPC) were determined by the JoinPoint regression model. The age-period-cohort model was used to estimate the effects of age, period, and cohort. (3) Results: From 2006 to 2020, the general trend in RHD standardized mortality declined. The RHD mortality rate was higher in rural than in urban areas and among females than males. The elderly (over 60 years old) were at high risk for RHD deaths in China. The age effect increased with age, and the cohort effect showed a declining trend as chronology grew, but the period effect was not significant. (4) Conclusions: China has achieved great success in RHD, but RHD mortality may increase with age. Compared with the period effect, age and cohort effects dominated the risk of RHD deaths.

The Age-Period-Cohort-Interaction Model for Describing and Investigating Inter-cohort Deviations and Intra-cohort Life-course Dynamics

Social scientists have frequently sought to understand the distinct effects of age, period, and cohort, but disaggregation of the three dimensions is difficult because cohort = period - age. We argue that this technical difficulty reflects a disconnection between how cohort effect is conceptualized and how it is modeled in the traditional age-period-cohort framework. We propose a new method, called the age-period-cohort-interaction (APC-I) model, that is qualitatively different from previous methods in that it represents Ryder's (1965) theoretical account about the conditions under which cohort differentiation may arise. This APC-I model does not require problematic statistical assumptions and the interpretation is straightforward. It quantifies inter-cohort deviations from the age and period main effects and also permits hypothesis testing about intra-cohort life-course dynamics. We demonstrate how this new model can be used to examine age, period, and cohort patterns in women's labor force participation.

Burden of carbon monoxide poisoning in China, 1990–2019: A systematic analysis of data from the global burden of disease study 2019

Background

Carbon monoxide (CO) poisoning is one of the most common toxic occupational diseases, but related data in China are scarce. A better understanding of the burden of CO poisoning is essential for improving its management.

Methods

A systematic analysis of data from the Global Burden of Disease (GBD) Study 2019 was conducted. Following the general analytical strategy used in the GBD Study 2019, the sex- and age-specific incidence and mortality rates of CO poisoning and disability-adjusted life years (DALYs) due to CO poisoning in China were analyzed. Estimated average annual percentage changes (AAPCs) in age-standardized rates were calculated by joinpoint regression analysis. The effects of age, period and cohort on the incidence of CO poisoning and DALYs due to CO poisoning were estimated by an age-period-cohort model.

Results

The age-standardized incidence and mortality rates as well as DALYs of CO poisoning per 100,000 population were estimated to be 21.82 [95% uncertainty interval (UI): 15.05–29.98], 0.93 (95% UI: 0.63–1.11), and 40.92 (95% UI: 28.43–47.85), respectively, in 2019. From 1990 to 2019, the AAPCs in the age-standardized incidence significantly increased in both males and females, while the age-standardized mortality rates and DALYs significantly decreased in both males and females. The incidence of CO poisoning peaked in individuals aged 15–19 years. Males had a higher burden of CO poisoning than females. The age effect showed that the relative risks (RRs) of incident CO poisoning decreased with age among males and females and that individuals aged 15–24 years had the highest RRs. The RRs of incident CO poisoning increased with time. The cohort effect showed that the incidence increased in successive birth cohorts.

Conclusions

The incidence of CO poisoning in China increased from 1990 to 2019. More attention should be given to improving the burden of CO poisoning in Chinese adolescents. The results of this study can be used by health authorities to inform preventative measures to reduce the burden of CO poisoning.

Time Trends in Psoriasis and Psoriatic Arthritis Incidence from 2002 to 2016 in Taiwan: An Age–Period–Cohort Analysis

Background: Psoriatic disease is a chronic inflammatory disease that is associated with morbidity and a poor quality of life. However, studies on the trends of psoriatic disease incidence are limited. We examined trends in psoriasis and psoriatic arthritis from 2002 to 2016 in Taiwan and distinguished the effects of age, period, and cohort on those trends. Methods: Data from the National Health Insurance Research Database were analyzed for the annual incidence of psoriasis and psoriatic arthritis. An age–period–cohort model was designed in order to investigate the effects of each age, period, and birth cohort on the incidence. Results: From 2002 to 2016, the incidence of psoriasis significantly decreased from 43.33 to 23.14 per 100,000 persons. The incidence of psoriatic arthritis significantly increased from 3.57 to 5.22 per 100,000 persons. In the age–period–cohort analysis, the net age effect on the incidence of psoriasis and psoriatic arthritis increased with advancing age (6-fold and 7.7-fold difference, respectively). Conclusion: The age–period–cohort analysis revealed that the incidence of psoriasis and psoriatic arthritis is associated with older age and early birth cohorts. Elderly individuals in Taiwan may be at a higher risk of developing new-onset psoriasis and psoriatic arthritis.

Trends in Musculoskeletal Rehabilitation Needs in China From 1990 to 2030: A Bayesian Age-Period-Cohort Modeling Study

Background

Disability and medical expenses caused by musculoskeletal disorders in China had a great impact on the global health and economy. Rehabilitation is essential for dealing with musculoskeletal disorders. However, China's musculoskeletal rehabilitation needs remain unknown. This study aimed to examine the secular trends for musculoskeletal rehabilitation needs in China from 1990 to 2030.

Methods

Data on musculoskeletal rehabilitation needs were extracted from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) repository. Estimated annual percentage changes (EAPCs) were calculated to reflect fluctuations in the age-standardized rates. The Bayesian age-period-cohort models were used to project rehabilitation needs.

Results

The number of prevalent cases and years lived with disability (YLD) counts in need of musculoskeletal rehabilitation increased greatly in China from 1990 to 2019. There will be 465.9 million Chinese people in need of rehabilitation, with the age-standardized prevalence rate increasing to 21,151.0 [2.5-97.5% predictive interval (95% PI) 14,872.6-27,429.3] per 100,000 persons in 2030. Similarly, the YLD counts will increase to 40.1 million, with the age-standardized YLD rate increasing to 1,811.2 (95% PI 1,232.5-2,390.0) per 100,000 persons in 2030.

Conclusions

Increasing trends in musculoskeletal rehabilitation needs were found from 1990 to 2019, which will be anticipated through 2030. Rehabilitation is suggested to be integrated into primary care settings.

An Age-Period-Cohort Approach to Analyse Late-Life Depression Prevalence in Six European Countries, 2004-2016

Late-life depression is a condition that affects an ever-growing share of the population in ageing societies. While depression prevalence varies across countries for a myriad of reasons, generational factors, expressed in the shared experience of birth cohorts, may also play a part in such differentials. This paper describes the presence of age, period, and cohort (APC) effects in late-life depression prevalence trends (for adults aged 50 and above) for selected countries in Europe, using the Survey of Health and Ageing and Retirement of Europe (SHARE). We analysed six countries during the 2004-2016 period: Denmark, Sweden, and Germany, with a lower baseline prevalence, and Italy, Spain, and France, with a higher baseline prevalence. By applying a set of APC statistical models to visualise linear and nonlinear effects, we found that all countries followed a J-shaped curve when describing the transversal and longitudinal age trajectories of late-life depression. We also found a combination of nonlinear effects present in Germany, France and Sweden in males, indicating that younger male cohorts had a higher relative risk of depression. In females, we found nonlinear cohort effects, indicating that younger and older cohorts presented a higher risk of depression in Sweden and Germany and a lower risk in Spain. The presence of an increased risk for younger male cohorts may be indicative of a new trend in some countries, which may reduce the sex gap in prevalence. Future analysis should focus on the causes and mechanisms that lead to differential risks across cohorts.

How a faecal immunochemical test screening programme changes annual colorectal cancer incidence rates: an Italian intention-to-screen study

Background

This study aimed to evaluate the effectiveness of a biennial faecal immunochemical test (FIT) screening programme in reducing annual colorectal cancer (CRC) incidence in its dynamic target population.

Methods

The target population included over 1,000,000 persons aged 50–69 living in a region of northern Italy. The average annual response rate to invitation was 51.4%. Each observed annual age-standardised (Europe) rate per 100,000 persons between 2005, the year of introduction of the programme, and 2016 was compared with each expected annual rate as estimated with age-period-cohort (men) and age-period (women) models.

Results

For both sexes, the rates observed in 1997–2004 and those expected in 2005–2016 were stable. Observed rates increased in 2005, peaked in 2006 (the first full year of screening), dropped significantly below the expected level in 2009, and continued to decrease until 2013 (the eighth full year), after which no further significant changes occurred. In the pooled years 2013–2016, the observed incidence rate per 100,000 persons was 102.2 [95% CI: 97.4, 107.1] for men, 75.6 [95% CI: 71.6, 79.7] for women and 88.4 [95% CI: 85.3, 91.5] for both sexes combined, with an observed:expected incidence rate ratio of 0.68 [95% CI: 0.65, 0.71], 0.79 [95% CI: 0.76, 0.82] and 0.72 [95% CI: 0.66, 0.81], respectively.

Discussion

The study provided multiple consistent proofs of a causal relationship between the introduction of screening and a stable 28% decrease in annual CRC incidence after eight years.

Forecast of peak attainment and imminent decline after 2017 of oral cancer incidence in men in Taiwan

Oral cancer is the fourth most common cancer among men in Taiwan. The age-standardized incidence rate of oral cancer among men in Taiwan has increased since 1980 and became six times greater in 2014. To enable effective public health planning for oral cancer, research on the projection of oral cancer burden is essential. We conducted an age-period-cohort analysis on the incidence of oral cancer among men in Taiwan from 1997 to 2017 and extrapolated the trend to 2025. We found that the period trends for young adults aged between 25 and 44 have already peaked before 2017; the younger, the earlier, and then the trends declined. The cohort trends have peaked roughly at the 1972 birth cohort and then declined for all ages. Despite the increasing trend in the age-standardized incidence rate for oral cancer among men in Taiwan from 1997 to 2017, we forecast a peak attained, an imminent decline after 2017, and a decrease of 8.4% in age-standardized incidence rate from 2017 to 2025. The findings of this study contribute to developing efficient and comprehensive strategies for oral cancer prevention and control.

Birth cohort relative to an influenza A virus's antigenic cluster introduction drives patterns of children's antibody titers

An individual's antibody titers to influenza A strains are a result of the complicated interplay between infection history, cross-reactivity, immune waning, and other factors. It has been challenging to disentangle how population-level patterns of humoral immunity change as a function of age, calendar year, and birth cohort from cross-sectional data alone. We analyzed 1,589 longitudinal sera samples from 260 children across three studies in Nicaragua, 2006-16. Hemagglutination inhibition (HAI) titers were determined against four H3N2 strains, one H1N1 strain, and two H1N1pdm strains. We assessed temporal patterns of HAI titers using an age-period-cohort modeling framework. We found that titers against a given virus depended on calendar year of serum collection and birth cohort but not on age. Titer cohort patterns were better described by participants' ages relative to year of likely introduction of the virus's antigenic cluster than by age relative to year of strain introduction or by year of birth. These cohort effects may be driven by a decreasing likelihood of early-life infection after cluster introduction and by more broadly reactive antibodies at a young age. H3N2 and H1N1 viruses had qualitatively distinct cohort patterns, with cohort patterns of titers to specific H3N2 strains reaching their peak in children born 3 years prior to that virus's antigenic cluster introduction and with titers to H1N1 and H1N1pdm strains peaking for children born 1-2 years prior to cluster introduction but not being dramatically lower for older children. Ultimately, specific patterns of strain circulation and antigenic cluster introduction may drive population-level antibody titer patterns in children.

Age, Period, and Cohort Effects of Internalizing Symptoms Among US Students and the Influence of Self-Reported Frequency of Attaining 7 or More Hours of Sleep: Results From the Monitoring the Future Survey 1991-2019

Adolescent internalizing symptoms have increased since 2010, whereas adequate sleep has declined for several decades. It remains unclear how self-reported sleep attainment has affected internalizing-symptoms trends. Using 1991-2019 data from the Monitoring the Future Study (n ~ 390,000), we estimated age-period-cohort effects in adolescent internalizing symptoms (e.g., loneliness, self-esteem, self-derogation, depressive affect) and the association with yearly prevalence of a survey-assessed, self-reported measure of attaining ≥7 hours of sleep most nights. We focused our main analysis on loneliness and used median odds ratios to measure variance in loneliness associated with period differences. We observed limited signals for cohort effects and modeled only period effects. The feeling of loneliness increased by 0.83% per year; adolescents in 2019 had 0.68 (95% CI: 0.49, 0.87) increased log odds of loneliness compared with the mean, which was consistent by race/ethnicity and parental education. Girls experienced steeper increases in loneliness than boys (P < 0.0001). The period-effect median odds ratio for loneliness was 1.16 (variance = 0.09; 95% CI: 0.06, 0.17) before adjustment for self-reported frequency of getting ≥7 hours sleep versus 1.07 (variance = 0.02; 95% CI: 0.01, 0.03) after adjustment. Adolescents across cohorts are experiencing worsening internalizing symptoms. Self-reported frequency of <7 hours sleep partially explains increases in loneliness, indicating the need for feasibility trials to study the effect of increasing sleep attainment on internalizing symptoms.

Time trends in cardiovascular disease mortality attributable to non-optimal temperatures in China: An age-period-cohort analysis using the Global Burden of Disease Study 2019

Background

Associations between non-optimal temperatures and cardiovascular disease (CVD) mortality risk have been previously reported, yet the trends of CVD mortality attributable to non-optimal temperatures remain unclear in China. We analyzed trends in CVD mortality attributable to non-optimal temperatures and associations with age, period, and birth cohort.

Methods

Data were obtained from the Global Burden of Disease Study (GBD) 2019. Joinpoint regression analysis was used to calculate annual percent change (APC) and average annual percent change (AAPC) from 1990 to 2019. We used the age-period-cohort model to analyze age, period, and cohort effects in CVD mortality attributable to non-optimal temperatures between 1990 and 2019.

Results

The age-standardized mortality rate (ASMR) of CVD attributable to non-optimal temperature generally declined in China from 1990 to 2019, whereas ischemic heart disease (IHD) increased slightly. Low temperatures have a greater death burden than high temperatures, but the death burden from high temperatures showed steady increases. Joinpoint regression analysis showed that CVD mortality decreased in all age groups except for IHD, and the decreases were greater in females than in males. The mortality of CVD attributable to non-optimal temperatures of males was higher than females. The mortality rate showed an upwards trend with age across all CVD categories. Period risks were generally found in unfavorable trends. The cohort effects showed a progressive downward trend during the entire period.

Conclusion

Although there have been reductions in CVD mortality attributable to non-optimum temperatures, the mortality of IHD has increased and the burden from non-optimal temperatures remains high in China. In the context of global climate change, our results call for more attention and strategies to address climate change that protect human health from non-optimal temperatures.

Single-cell profiling of immune system alterations in lymphoid, barrier and solid tissues in aged mice

Aging exerts profound and paradoxical effects on the immune system, at once impairing proliferation, cytotoxicity and phagocytosis, and inducing chronic inflammation. Previous studies have focused on individual tissues or cell types, while a comprehensive multisystem study of tissue-resident and circulating immune populations during aging is lacking. Here we reveal an atlas of age-related changes in the abundance and phenotype of immune cell populations across 12 mouse tissues. Using cytometry-based high parametric analysis of 37 mass-cytometry and 55 spectral flow-cytometry parameters, mapping samples from young and aged animals revealed conserved and tissue-type-specific patterns of both immune atrophy and expansion. We uncovered clear phenotypic changes in both lymphoid and myeloid lineages in aged mice, and in particular a contraction in natural killer cells and plasmacytoid dendritic cells. These changes correlated with a skewing towards myelopoiesis at the expense of early lymphocyte genesis in aged mice. Taken together, this atlas represents a comprehensive, systematic and thorough resource of the age-dependent alterations of the mammalian immune system in lymphoid, barrier and solid tissues.

Characterizing Trends in Cancer Patients' Survival Using the JPSurv Software

BACKGROUND

Improvements in cancer survival are usually assessed by comparing survival in grouped years of diagnosis. To enhance analyses of survival trends, we present the joinpoint survival model webtool (JPSurv) that analyzes survival data by single year of diagnosis and estimates changes in survival trends and year-over-year trend measures.

METHODS

We apply JPSurv to relative survival data for individuals diagnosed with female breast cancer, melanoma cancer, non-Hodgkin lymphoma (NHL), and chronic myeloid leukemia (CML) between 1975 and 2015 in the Surveillance, Epidemiology, and End Results Program. We estimate the number and location of joinpoints and the trend measures and provide interpretation.

RESULTS

In general, relative survival has substantially improved at least since the mid-1990s for all cancer sites. The largest improvements in 5-year relative survival were observed for distant-stage melanoma after 2009, which increased by almost 3 survival percentage points for each subsequent year of diagnosis, followed by CML in 1995-2010, and NHL in 1995-2003. The modeling also showed that for patients diagnosed with CML after 1995 (compared with before), there was a greater decrease in the probability of dying of the disease in the 4th and 5th years after diagnosis compared with the initial years since diagnosis.

CONCLUSIONS

The greatest increases in trends for distant melanoma, NHL, and CML coincided with the introduction of novel treatments, demonstrating the value of JPSurv for estimating and interpreting cancer survival trends.

IMPACT

The JPSurv webtool provides a suite of estimates for analyzing trends in cancer survival that complement traditional descriptive survival analyses.

Mortality trends in chronic liver disease and cirrhosis from 1981 to 2015 in Taiwan

Background

Globally, the morbidity and mortality rates for chronic liver disease and cirrhosis are increasing. The National Viral Hepatitis Therapy Program in Taiwan was implemented in 2003, but evidence regarding the program’s effect on the trends of mortality for chronic liver disease and cirrhosis is limited.

Methods

We analyzed mortality rates for chronic liver disease and cirrhosis in Taiwan for the period from 1981 to 2015. An autoregressive age–period–cohort model was used to estimate age, period, and cohort effects.

Results

Age-adjusted mortality rates for chronic liver disease and cirrhosis all displayed a flat but variable trend from 1981 to 2004 and a decreasing trend thereafter for both sexes. The age–period–cohort model revealed differential age gradients between the two sexes; mortality rates in the oldest age group (90–94 years) were 12 and 66 times higher than those in the youngest age group (30–34 years) for men and women, respectively. The period effects indicated that mortality rates declined after 2004 in both sexes. Mortality rates decreased in men but increased in women in the 1891–1940 birth cohorts and increased in both sexes in the birth cohorts from 1950 onward.

Conclusions

The National Viral Hepatitis Therapy Program in Taiwan may have contributed to the decrease in mortality rates for chronic liver disease and cirrhosis in adulthood.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12963-021-00269-w.

Secular Trends in the Incidence of and Mortality Due to Alzheimer's Disease and Other Forms of Dementia in China From 1990 to 2019: An Age-Period-Cohort Study and Joinpoint Analysis

Background

The number of individuals with dementia is increasing, which negatively affects families, communities, and health care systems worldwide. The changes in the incidence of and mortality due to Alzheimer’s disease and other forms of dementia at the national level in China have remained unknown over the past three decades.

Methods

Following the general analytical strategy used in the Global Burden of Disease Study (GBD) 2019, the age- and sex-specific incidence and mortality rates for dementia in China were analyzed. Trends in the incidence of and mortality due to dementia from 1990 to 2019 were assessed by joinpoint regression analysis. The effects of age, period and cohort on the incidence of and mortality due to dementia were estimated by an age-period-cohort model.

Results

The age-standardized incidence and mortality rates per 100,000 population were 103.83 (95% UI, 87.93–118.87) and 23.32 (95% UI, 5.66–61.31), respectively, for dementia in 2019. From 1990 to 2019, a significant average annual percentage change (AAPC) in the age-standardized incidence rate was observed in both males [0.49% (95% CI, 0.43–0.55%)] and females [0.31% (95% CI, 0.24–0.38%)], and the age-standardized mortality rate significantly increased in males [0.42% (95% CI, 0.31–0.53%)]. The population aged 55–59 years had the highest AAPC in the incidence of dementia [0.87% (95% CI, 0.81–0.93%)]. The age effect showed that the relative risks (RRs) of incident dementia and dementia-associated mortality increased with age among males and females, and individuals aged 60 years and older had significantly higher RRs. The RR of incident dementia increased with time, and the RR started to substantially increase in 2009. The cohort effect showed that the incidence decreased in successive birth cohorts.

Conclusion

Alzheimer’s disease and other forms of dementia continue to become more common among males and females in China, and the associated mortality rate in males significantly increased from 1990 to 2019. Early interventions should be implemented to reduce the burden of dementia on individuals at high risk in China.

A Survivorship-Period-Cohort Model for Cancer Survival: Application to Liver Cancer in Taiwan, 1997-2016

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

The Impact of the Human Papillomavirus Vaccine on High-Grade Cervical Lesions in Urban and Rural Areas: An Age-Period-Cohort Analysis

Simple Summary

Human papillomavirus (HPV) vaccination disparities between urban and rural regions may moderate the vaccine’s impact on reducing cervical precancer (CIN2+) and cancer incidence. We assessed population-level trends in CIN2+ incidence (2008–2018) in urban and rural areas among Medicaid-enrolled women aged 18–39 years in Tennessee, United States. A sub-group analysis among women screened for cervical cancer was conducted to control for changing screening trends. CIN2+ incidence among young women aged 18–20 and 21–24 years, who most likely benefited from the HPV vaccine, declined similarly between urban and rural areas, although significant declines began earlier in urban versus rural areas. Our results suggest evidence of HPV vaccine impact regardless of urbanicity but demonstrate lagged impact in rural areas. These findings emphasize the importance of reducing barriers to HPV vaccination, particularly in rural areas, to improve the reduction of cervical precancer and cancer incidence, toward the World Health Organization’s goals of eliminating cervical cancer.

Abstract

Disparities in human papillomavirus (HPV) vaccination exist between urban (metropolitan statistical areas (MSAs)) and rural (non-MSAs) regions. To address whether the HPV vaccine’s impact differs by urbanicity, we examined trends in cervical intraepithelial neoplasia grades 2 or 3 and adenocarcinoma in situ (collectively, CIN2+) incidence in MSAs and non-MSAs among Tennessee Medicaid (TennCare)-enrolled women aged 18–39 years and among the subset screened for cervical cancer in Tennessee, United States. Using TennCare claims data, we identified annual age-group-specific (18–20, 21–24, 25–29, 30–34, and 35–39 years) CIN2+ incidence (2008–2018). Joinpoint regression was used to identify trends over time. Age–period–cohort Poisson regression models were used to evaluate age, period, and cohort effects. All analyses were stratified by urbanicity (MSA versus non-MSA). From 2008–2018, 11,243 incident CIN2+ events (7956 in MSAs; 3287 in non-MSAs) were identified among TennCare-enrolled women aged 18–39 years. CIN2+ incident trends (2008–2018) were similar between women in MSAs and non-MSAs, with largest declines among ages 18–20 (MSA average annual percent change (AAPC): −30.4, 95% confidence interval (95%CI): −35.4, −25.0; non-MSA AAPC: −30.9, 95%CI: −36.8, −24.5) and 21–24 years (MSA AAPC: −14.8, 95%CI: −18.1, −11.3; non-MSA AAPC: −15.1, 95%CI: −17.9, −12.2). Significant declines for ages 18–20 years began in 2008 in MSAs compared to 2010 in non-MSAs. Trends were largely driven by age and cohort effects. These patterns were consistent among screened women. Despite evidence of HPV vaccine impact on reducing CIN2+ incidence regardless of urbanicity, significant declines in CIN2+ incidence were delayed in non-MSAs versus MSAs.

Disparities of birth cohort effects on pancreatic cancer incidence between the United States and urban China

Background

Pancreatic cancer has been associated with lifestyle factors, but few comparative studies were conducted among countries of different culture and lifestyle habits. This study compared the trends of pancreatic cancer incidence and birth cohort effects in the United States and urban China and explored the potential discrepancies of risk patterns.

Materials and methods

Age-standardized incidence rates (ASIRs) were calculated using data from national or regional cancer registries of the United States and two large cities of China (Shanghai, Hong Kong). The temporal trends of incidence were assessed by joinpoint regression. The effects of birth cohort and calendar period were identified through age–period–cohort modeling.

Results

The ASIR in the United States from 1976 to 2015 was 8.26/100 000, which was higher than that in Hong Kong (4.29/100 000) and Shanghai of China (6.63/100 000). Shanghai had lower incidence (4.41/100 000) in 1976-1980 but increased annually by 1.38% in males and 1.67% in females, with a sharper upward trend than the United States and Hong Kong. Males had higher risks than females, with a male-to-female ratio of 1.34, 1.44, and 1.37 in the United States, Hong Kong, and Shanghai, respectively. A significant and prominent increase in incidence rate was observed among successive generations in China particularly for Shanghai, but such a pattern was not apparent in the United States.

Conclusions

The differences in pancreatic cancer incidence by sex may be multi-factorial involving known risk factors like tobacco smoking and alcohol consumption. The significant birth cohort effects among recent and early generations in the Shanghai population were in line with a society in socioeconomic transition and adoption of Western lifestyle mainly including consumption of calorie-rich foods and physical inactivity. Differences in these risk patterns will have implications on health care efforts and policies for cancer control.

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The ASIR of pancreatic cancer in the U.S. is higher than that in urban China.

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Higher risk of pancreatic cancer was observed in the youth of urban China, but this pattern was not prominent in the U.S.

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The disparities of birth cohort effects are consistent with a society in socioeconomic transition.

Trends in breast and cervical cancer in India under National Cancer Registry Programme: An Age-Period-Cohort analysis

BACKGROUND

Trend analysis in cancer quantifies the incidence rate and explains the trend and pattern. Breast and cervical cancers are the two most common cancers among Indian women which contributed 39.4 % to the total cancer in India for the year 2020. This study aimed to report the time trends in cancer incidence of breast and cervical cancer using Age-Period-Cohort (APC) model from five Population Based Cancer Registries (PBCRs) in India for the period of 1985-2014.

METHOD

Age-Period-Cohort model was fitted to five PBCRs of Bangalore, Chennai, Delhi, Bhopal and Barshi rural for breast and cervical cancer for 25-74 age-groups. The Estimated Annual Percent Change (EAPC) was calculated. Rate Ratio (RR) of cohort effects were estimated with a constraint of period slope to be zero (p = 0) since cohort has a stronger association with incidence than period.

RESULT

A significant increase was noted in breast cancer in all PBCRs (EAPC, Range: Delhi, 1.2 % to Bangalore, 2.7 %) while significant decrease in cervical cancer (EAPC, Range: Bangalore -2.5 % to Chennai, -4.6 %) from all the PBCRs including Barshi rural during the period. RR estimates for breast cancer showed increasing trend whereas cervical cancer showed decreasing trend in successive birth cohorts across all five PBCRs.

CONCLUSION

In both breast and cervical cancers, a significant age, cohort and period effect was noted in Bangalore, Chennai and Delhi. Despite period effect, the cohort effect was predominant and it may be attributed to the generational changes in risk factors among cancer breast and cervix.

Age, period, and cohort effects on suicide death in the United States from 1999 to 2018: moderation by sex, race, and firearm involvement

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

Global trend of aetiology-based primary liver cancer incidence from 1990 to 2030: a modelling study

BACKGROUND

Predictions of primary liver cancer (PLC) incidence rates and case numbers are critical to understand and plan for PLC disease burden.

METHODS

Data on PLC incidence rates and case numbers from 1990 to 2017 were retrieved from the Global Burden of Disease database. The estimated average percentage change (EAPC) was calculated to quantify the trends of PLC age-standardized incidence rates (ASRs). Bayesian age-period-cohort models were constructed to project PLC incidence rates and case numbers through 2030.

RESULTS

Globally, the PLC case number doubled from 472 300 in 1990 to 953 100 in 2017. The case number will further increase to 1 571 200 in 2030, and the ASR will increase from 11.80 per 100 000 in 2018 to 14.08 per 100 000 in 2030. The most pronounced increases are observed in people afflicted by non-alcoholic steatohepatitis (NASH) and in older people. The trends of PLC incidence rates between 1990 and 2030 are heterogeneous among countries and can be summarized as five scenarios: (i) 46 countries that have and will continue to experience a persistent increase (e.g. Australia); (ii) 21 countries that experienced an initial decrease (or remained stable) but are predicted to increase (e.g. China); (iii) 7 countries that experienced an initial increase but are predicted to remain stable (e.g. USA); (iv) 29 countries that experienced an initial increase but are predicted to decrease (e.g. Egypt); and (v) 82 countries that have and will continue to experience a persistent decrease (e.g. Japan).

CONCLUSION

PLC incidence rates and case numbers are anticipated to increase at the global level through 2030. The increases in people afflicted by NASH and among older people suggest a dearth of attention for these populations in current prevention strategies and highlight their priority in future schedules for global control of PLC.

Trends in cannabis use and attitudes toward legalization and use among Australians from 2001-2016: an age-period-cohort analysis

BACKGROUND AND AIMS

Changes in cannabis legalization and availability in Australia necessitate monitoring use and attitudes. We estimated age-period-cohort effects of past-year cannabis use and attitudes toward criminalization and legalization.

DESIGN

Analysis of six waves of the Australian National Drug Strategy Household Survey (NDSHS) every 3 years (2001-2016).

SETTING AND PARTICIPANTS

The study was nationally representative of Australian households using multistage random sampling, totaling 145 168 respondents 18-79 years old. Data were collected using telephone, face-to-face, and drop-and-collect. Sample sizes per analysis varied based on data availability (~107 000-127 000 per model).

MEASUREMENTS

Six waves of data for past-year cannabis use (by sex and education), attitudes toward criminalization and legalization.

FINDINGS

Past-year cannabis use decreased in young adults ages 18-35 from 2001-2016 (25.1%-18.6%) and increased in middle adults ages 36-55 (8.6%-10.1%) and older adults ages 56-79 (0.6%-3.0%). We observed a positive period effect and negative cohort effect for recent cohorts for past-year use (e.g. 1955 cohort had 1.41 (95% CI: [1.11, 1.70]) increased log odds vs. 1998 cohort had -2.86 (95% CI: [-3.17, -2.55]) increased log odds) compared with the mean across years. Results were consistent by sex and varied by education. We observed a negative period effect for criminalization favorability (0.14 (95% CI: [0.003, 0.28]) increased log odds in 2001 vs. -0.31 (95% CI: [-0.45, -0.17]) increased log odds in 2016) and positive cohort effect for recent cohorts. Last, we observed a positive period effect for legalization support (-0.03 (95% CI: [-0.20, 0.14]) increased log odds in 2001 vs. 0.38 (95% CI: [0.22, 0.55]) increased log odds in 2016) and negative cohort effect for recent cohorts.

CONCLUSION

Cannabis use appears to be increasing in Australia among adults over 35, while decreasing among adolescents and young adults. Legalization support also appears to have been increasing since 2007, signaling discordance between use and attitudes among adolescents and young adults, and potentially predicting increases in use over time.

Future Alcohol-Attributable Mortality in France Using a Novel Generalizable Age-Period-Cohort Projection Methodology

AIM

To forecast age- and sex-specific alcohol-attributable mortality in France for the period 2015-2050 using a novel generalizable methodology that includes different scenarios regarding period and cohort change.

METHODS

For the French national population aged 25-90 years (1979-2014), we estimated alcohol-attributable mortality by mortality from the main causes of death wholly attributable to alcohol, plus liver cirrhosis mortality. We modelled sex-specific alcohol-attributable mortality by adjusting for age, period and birth cohort. We forecasted the model parameters to obtain future age- and sex-specific alcohol-attributable mortality up until 2050 using a conventional baseline, scenario I (favourable period change) and scenario II (unfavourable cohort change).

RESULTS

Alcohol-attributable mortality is clearly declining in France, with the decline decelerating from 1992 onwards. In 2014, the age-standardized alcohol-attributable mortality rates, in deaths per 100,000, were 34.7 among men and 9.9 among women. In 2050, the estimated rates are between 10.5 (prediction interval: 7.6-14.4; scenario I) and 17.6 (13.1-23.7; scenario II) among men, and between 1.1 (0.7-1.7; scenario I) and 1.8 (1.2-2.9; scenario II) among women; which implies declines of 58% for men and 84% for women (baseline).

CONCLUSION

Alcohol-attributable mortality in France is expected to further decline in the coming decades, accompanied by age pattern changes. However, France's levels are not expected to reach the current lower levels in Italy and Spain for 15 years or more. Our results point to the value of implementing preventive policy measures that discourage alcohol consumption among people of all ages, but especially among adolescents.

Multidimensional penalized splines for incidence and mortality-trend analyses and validation of national cancer-incidence estimates

BACKGROUND

Cancer-incidence and mortality-trend analyses require appropriate statistical modelling. In countries without a nationwide cancer registry, an additional issue is estimating national incidence from local-registry data. The objectives of this study were to (i) promote the use of multidimensional penalized splines (MPS) for trend analyses; (ii) estimate the national cancer-incidence trends, using MPS, from only local-registry data; and (iii) propose a validation process of these estimates.

METHODS

We used an MPS model of age and year for trend analyses in France over 1990-2015 with a projection up to 2018. Validation was performed for 22 cancer sites and relied essentially on comparison with reference estimates that used the incidence/health-care ratio over the period 2011-2015. Alternative estimates that used the incidence/mortality ratio were also used to validate the trends.

RESULTS

In the validation assessment, the relative differences of the incidence estimates (2011-2015) with the reference estimates were <5% except for testis cancer in men and < 7% except for larynx cancer in women. Trends could be correctly derived since 1990 despite incomplete histories in some registries. The proposed method was applied to estimate the incidence and mortality trends of female lung cancer and prostate cancer in France.

CONCLUSIONS

The validation process confirmed the validity of the national French estimates; it may be applied in other countries to help in choosing the most appropriate national estimation method according to country-specific contexts. MPS form a powerful statistical tool for trend analyses; they allow trends to vary smoothly with age and are suitable for modelling simple as well as complex trends thanks to penalization. Detailed trend analyses of lung and prostate cancers illustrated the suitability of MPS and the epidemiological interest of such analyses.

Impacts of Human Papillomavirus Immunization Programs on Rates of Anogenital Warts in British Columbia, Canada, 2000 to 2017

BACKGROUND

In 2008, British Columbia (BC) implemented a school-based quadrivalent human papillomavirus (HPV-4) immunization program for girls born in 1994 or later. In 2015, an expanded clinic-based program included men who report sex with men (MSM) born in 1989 or later. To evaluate the impacts of HPV-4 programs on anogenital warts (AGWs), diagnosis rates were measured among women who report sex with men (WSM), men who report sex with women (MSW), and MSM.

METHODS

Diagnoses of AGW were ascertained from 16 sexually transmitted infection clinics. Rates were calculated as new AGW diagnoses over person-years (py) at risk and stratified by age group, calendar period, and birth cohort. Adjusted relative rates (aRR) were estimated using multivariable Poisson regression.

RESULTS

There were 204,832 clinic visits by 85,158 individuals: 28,366 (33%) WSM, 35,688 (42%) MSW, and 14,534 (17%) MSM. After adjusting for age and period, AGW rates in the 1994-1996 birth cohort decreased by 56% overall (1.21 vs. 2.72 cases/100 py; aRR, 0.44; 95% confidence interval [CI], 0.34-0.59), 65% among WSM (0.97 vs. 2.77 cases/100 py; aRR, 0.35; 95% CI, 0.22-0.57), 58% among MSW (1.60 vs. 3.78 cases/100 py; aRR, 0.42; 95% CI, 0.28-0.65), and 41% among MSM (1.14 vs. 1.19 cases/100 py; aRR, 0.59; 95% CI, 0.38-0.91) versus the 1991-1993 birth cohort.

CONCLUSIONS

The HPV-4 programs had significant impacts on lowering AGW rates in BC. The greatest decrease was among WSM eligible for the school-based program, followed by birth cohorts of men who likely have sex with HPV-4 eligible women. The smallest decrease among MSM may reflect the later introduction of the clinic-based program.

Time trends of major cancers incidence and mortality in Guangzhou, China 2004-2015: A Joinpoint and Age-Period-Cohort Analysis

Background

Cancer is an important focus of public health worldwide. This study aims to provide a comprehensive overview of temporal trends in incidence and mortality of leading cancer in Guangzhou, China from 2004 to 2015.

Methods

Data were collected from the population‐based registry in Guangzhou. Age‐standardized incidence rate (ASIR) and age‐standardized mortality rate (ASMR) were calculated and Joinpoint regression was used for evaluating the average annual percent changes (AAPC) among the entire study period and the estimated annual percent changes (EAPC) in time segments. The effects of age, period, and birth cohort were assessed by the age–period–cohort model.

Results

The age‐standardized incidence and mortality by the world standard population decreased significantly among males with AAPC of −1.7% (95% CI: −3.0%, 0.2%) and −2.7% (95% CI: −4.3%, −1.1%) for all malignancies during 2004–2015, while among females, the age‐standardized incidence had a non‐significant reduction with AAPC of −1.3% (95% CI: −2.8%, 0.2%) and the age‐standardized mortality demonstrated a remarkable decline (AAPC −2.0%, 95% CI: −3.6%, −0.3%). For males, the most commonly diagnosed cancers were trachea, bronchus, and lung (TBL), liver, colorectal, nasopharyngeal, stomach, and prostate cancer. For females, breast, TBL, colorectal, liver stomach, and thyroid cancer ranked the top. Unfavorable trends were observed in ASIR of colorectal, thyroid, and prostate cancer. APC models yielded different ages, periods, and birth cohort effect patterns by cancer sites.

Conclusions

Cancer burden remained a public health challenge in Guangzhou as the aging population and lifestyles changes, despite declines in incidence and mortality rates in some cancers. Surveillance of cancer trends contributed to valuable insights into cancer prevention and control.