Age-period-cohort Model Research Articles

Impacts of risk aversion on tourism consumption: A hierarchical age-period-cohort analysis

This study extends tourism demand research by focusing on how an important psychological factor, risk aversion, affects tourism participation and expenditure. Based on five waves of national longitudinal data from the China Household Financial Survey, this study represents an initial attempt in the tourism literature to integrate a Heckman model with a hierarchical age–period–cohort model to decompose the effects of time-related factors (age, period, and birth cohorts) when analyzing the role of risk aversion in tourism decisions. Findings showed that risk aversion significantly influenced tourism participation and expenditure. The propensity to travel and the amount of tourism expenditure each declined over one's lifetime. Period and cohort effects differentially affected tourism participation and expenditure.

National situation, trends, and predictions of disease burden of atopic dermatitis in Chinese children and adolescents.

Atopic dermatitis (AD) is an important global health problem affecting children and adolescents and detailed national information of disease burden in China is lacking. We aimed to evaluate the national disease burden of AD in Chinese children and adolescent, to provide the temporal trends over the past 30 years and to predict the burden for the next 10 years. The data of AD in China, including incidence, prevalence, and DALY, and population data were obtained from the Global Burden of Disease Study 2019 (GBD study 2019), which were estimated using the DisMod-MR 2.1. We analyzed the three measures by age and sex; the age groups were <5 years, 5-9 years, 10-14 years, and 15-19 years. The joinpoint regression analyses was conducted to assess the temporal trends from 1990 to 2019. The Bayesian age-period cohort (BAPC) model was used to predict measures from 2020 to 2030. In 2019, the highest incidence case and rate were observed in <5 years group; for prevalence and disability adjusted life year (DALY), the groups of <5 years and 5-9 years showed similar higher levels and the groups of 10-14 years and 15-19 years had similar relatively lower levels. Overall, the male-to-female ratios were >1 in <5 years group and <1 in 10-14 and 15-19 age groups. The trend analyses found an overall trend of decrease in cases of the three measures; in recent about 3 years, slight increase trends were shown in cases and rates of the three measures in <5 years group. The prediction analyses found a slight decreasing trend for cases of these measures and a slight increasing trend for rates of these measures in the <5 years group in the next 10 years; the 5-9 years group was predicted to increase slightly in rates of the three measures. In conclusion, the groups of <5 years and 5-9 years are two important populations that need targeted measures to reduce disease burden of AD in China. Regarding sex disparity, we should pay more attention to males in <5 years group and to females in 10-19 years group.

Preventable burden of head and neck cancer attributable to tobacco and alcohol between 1990 and 2039 in China.

Tobacco use and heavy alcohol consumption are risk factors for head and neck cancer (HNC), including oral, pharynx, and larynx cancer. No study has investigated the preventable burden of HNC attributable to tobacco and alcohol in China. We extracted data from 1990 to 2019 from the Global Burden of Disease. The preventable burden attributable to tobacco and alcohol was estimated by subtracting the overlapping fraction derived from a literature search. Descriptive analyses were performed initially, followed by joinpoint regression and age-period-cohort (APC) analysis. The future burden was forecasted using a Bayesian APC model. The crude burden increased significantly, while the age-standardized rates showed a downward trend from 1990 to 2019 in China. Both all-age and age-standardized population attributable fractions rose significantly, potentially due to the poor prognosis of tobacco- and alcohol-associated HNC. The absolute burden would continue to climb in the next 20 years from 2019, largely due to population aging. For site-specific burden, compared with total, pharynx, and larynx cancer burden, the substantial upward trend of oral cancer burden indicated a strong interaction with risk factors such as genetic susceptibility, betel nut chewing, oral microbiota, and human papillomavirus. The burden of oral cancer attributable to tobacco and alcohol is a major concern and is anticipated to become more severe than cancer in other anatomic sites. Altogether, our study provides useful information to rethink the current restrictions on tobacco and alcohol, lean healthcare resources, and develop effective HNC prevention and control strategies.

Global, Regional, and National Prevalence of Gout From 1990 to 2019: Age-Period-Cohort Analysis With Future Burden Prediction.

Gout is a common and debilitating condition that is associated with significant morbidity and mortality. Despite advances in medical treatment, the global burden of gout continues to increase, particularly in high-sociodemographic index (SDI) regions. To address the aforementioned issue, we used age-period-cohort (APC) modeling to analyze global trends in gout incidence and prevalence from 1990 to 2019. Data were extracted from the Global Burden of Disease Study 2019 to assess all-age prevalence and age-standardized prevalence rates, as well as years lived with disability rates, for 204 countries and territories. APC effects were also examined in relation to gout prevalence. Future burden prediction was carried out using the Nordpred APC prediction of future incidence cases and the Bayesian APC model. The global gout incidence has increased by 63.44% over the past 2 decades, with a corresponding increase of 51.12% in global years lived with disability. The sex ratio remained consistent at 3:1 (male to female), but the global gout incidence increased in both sexes over time. Notably, the prevalence and incidence of gout were the highest in high-SDI regions (95% uncertainty interval 14.19-20.62), with a growth rate of 94.3%. Gout prevalence increases steadily with age, and the prevalence increases rapidly in high-SDI quantiles for the period effect. Finally, the cohort effect showed that gout prevalence increases steadily, with the risk of morbidity increasing in younger birth cohorts. The prediction model suggests that the gout incidence rate will continue to increase globally. Our study provides important insights into the global burden of gout and highlights the need for effective management and prophylaxis of this condition. The APC model used in our analysis provides a novel approach to understanding the complex trends in gout prevalence and incidence, and our findings can inform the development of targeted interventions to address this growing health issue.

The role of environmental factors on sporadic Creutzfeldt-Jakob disease mortality: evidence from an age-period-cohort analysis

Sporadic Creutzfeldt-Jakob disease (sCJD) is the most common form of prion diseases. The causes of sCJD are still unknown and exogenous factors may play a role. Worldwide, the number of patients with sCJD has progressively increased over time. This increase can be partly explained by increasing life expectancy and better case ascertainment, but a true increase in the number of sCJD cases cannot be excluded. We estimated mortality rates from sCJD in France (1992–2016) and studied variation in mortality rates by age, period, and time.We included all cases aged 45–89 years old who died with a probable/definite sCJD diagnosis based on the French national surveillance network. We used age-period-cohort (APC) Poisson regression models to study variation in mortality rates by sex, age, period, and time.A total of 2475 sCJD cases aged 45–89 years were included. Mortality rates increased with age, reached a peak between 75 and 79 years, and decreased thereafter. Mortality rates were higher in women than men at younger ages and lower at older ages. The full APC model with a sex×age interaction provided the best fit to the data, thus in favour of sex, age, period, and cohort effects on mortality rates. In particular, mortality rates increased progressively with successive birth cohorts.Based on 25 years of active surveillance in France, we show evidence for sex, age, period, and cohort effects on sCJD mortality. The identification of cohort effects suggests that environmental exposures may play a role in sCJD etiology.

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.

Risk Factors and Trends for HPV-Associated Subsequent Malignant Neoplasms among Adolescent and Young Adult Cancer Survivors.

Subsequent malignant neoplasms (SMN; new cancers that arise after an original diagnosis) contribute to premature mortality among adolescent and young adult (AYA) cancer survivors. Because of the high population prevalence of human papillomavirus (HPV) infection, we identify demographic and clinical risk factors for HPV-associated SMNs (HPV-SMN) among AYA cancer survivors in the SEER-9 registries diagnosed from 1976 to 2015. Outcomes included any HPV-SMN, oropharyngeal-SMN, and cervical-SMN. Follow-up started 2 months after their original diagnosis. Standardized incidence ratios (SIR) compared risk between AYA survivors and general population. Age-period-cohort (APC) models examined trends over time. Fine and Gray's models identified therapy effects controlling for cancer and demographic confounders. Of 374,408 survivors, 1,369 had an HPV-SMN, occurring on average 5 years after first cancer. Compared with the general population, AYA survivors had 70% increased risk for any HPV-SMN [95% confidence interval (CI), 1.61-1.79] and 117% for oropharyngeal-SMN (95% CI, 2.00-2.35); cervical-SMN risk was generally lower in survivors (SIR, 0.85; 95% CI, 0.76-0.95), but Hispanic AYA survivors had a 8.4 significant increase in cervical-SMN (SIR, 1.46; 95% CI, 1.01-2.06). AYAs first diagnosed with Kaposi sarcoma, leukemia, Hodgkin, and non-Hodgkin lymphoma had increased HPV-SMN risks compared with the general population. Oropharyngeal-SMN incidence declined over time in APC models. Chemotherapy and radiation were associated with any HPV-SMN among survivors with first HPV-related cancers, but not associated among survivors whose first cancers were not HPV-related. HPV-SMN in AYA survivors are driven by oropharyngeal cancers despite temporal declines in oropharyngeal-SMN. Hispanic survivors are at risk for cervical-SMN relative to the general population. Encouraging HPV vaccination and cervical and oral cancer screenings may reduce HPV-SMN burden among AYA survivors.

Comparison of Secular Trends in Peptic Ulcer Diseases Mortality in China, Brazil and India during 1990-2019: An Age-Period-Cohort Analysis.

Peptic ulcer disease (PUD) is a common disease worldwide, especially in developing countries. China, Brazil, and India are among the world's fastest-growing emerging economies. This study aimed to assess long-term trends in PUD mortality and explore the effects of age, period, and cohort in China, Brazil, and India. We collected data from the 2019 Global Burden of Disease Study and used an age-period-cohort (APC) model to estimate the effects of age, period, and cohort. We also obtained net drift, local drift, longitudinal age curve, and period/cohort rate ratios using the APC model. Between 1990 and 2019, the age-standardized mortality rates (ASMRs) of PUD and PUD attributable to smoking showed a downward trend in all countries and both sexes. The local drift values for both sexes of all ages were below zero, and there were obvious sex differences in net drifts between China and India. India had a more pronounced upward trend in the age effects than other countries. The period and cohort effects had a similar declining trend in all countries and both sexes. China, Brazil, and India had an inspiring decrease in the ASMRs of PUD and PUD attributable to smoking and to period and cohort effects during 1990-2019. The decreasing rates of Helicobacter pylori infection and the implementation of tobacco-restricting policies may have contributed to this decrease.

Abstract 5763: Risk factors, trends, and disparities in HPV-associated subsequent malignant neoplasms among adolescent and young adult cancer survivors

Abstract Background: Subsequent malignant neoplasms (SMN) are a leading cause of premature mortality among adolescent and young adult (AYA) cancer survivors, who have unique health needs. Human Papillomavirus-related second cancers (HPV-SMN) are generally preventable through screenings and vaccination. We identified disparities in HPV-SMN among AYA survivors by demographics and first cancer therapy, and examined temporal trends in incidence of HPV-SMN. Methods: We identified diagnoses of any HPV-SMN, oropharyngeal-SMN, and cervical-SMN among AYA survivors in the SEER 9 1976-2015 registries starting two months after the first cancer. Standardized incidence ratios (SIR) compared risk between AYA survivors and general population. We used Fine and Gray competing risk models to estimate hazard ratios (HR) of therapy on risk for HPV-SMN while controlling for cancer site and demographic confounders. Age-period-cohort (APC) models identified temporal trends in HPV-SMN incidence. Results: Of 374,408 survivors diagnosed with a first primary cancer ages 15-44, a total of 1,369 had an HPV-SMN occurring on average five years after the first cancer. Compared to the general population, AYA survivors had increased risks of 70% for any HPV-SMN (95%CI=1.61-1.79) and 117% for oropharyngeal-SMN (95%CI=2.00-2.35). Cervical-SMN risk was generally lower in survivors (SIR=0.85, 95%=CI 0.76-0.95). Hispanic AYA survivors had a significant increase in cervical-SMN relative to the general population (SIR=1.46, 95%CI=1.01-2.06). AYAs who were uninsured or on Medicaid at diagnosis had significant increases in HPV-SMN risk relative to the general populations (Uninsured SIR=5.23, 95%CI=2.26-10.31; Medicaid SIR=5.95, 95%CI=4.07-8.40). AYAs first diagnosed with Kaposi sarcoma, leukemia, Hodgkin, and Non-Hodgkin lymphoma had increased risk for HPV-SMN relative to the general population. Among survivors with HPV-related first primary cancers, radiation was associated with increased risk for HPV-SMN (HR=1.35, 95%CI-1.03-1.77). Among survivors whose first primary cancer was not HPV-related, chemotherapy was associated with increased risk for HPV-SMN (HR=1.20, 95%CI=1.00-1.44) but the general effect of treatment was not significant (p=0.16). In APC models, incidence of oropharyngeal-SMN significantly declined over time. Conclusion and Impact: While the overall risk is low, AYA survivors are at higher risk for HPV-SMNs than the general population, largely driven by oropharyngeal-SMN. Hispanic survivors are the only group at higher risk for cervical-SMN than the general population suggesting a need to improve their cervical cancer screening. Uninsured/Medicaid AYA survivors also face higher HPV-SMN risks. Improving access to screening and HPV vaccination is needed to reduce the burden of HPV-SMN in AYA survivors. Citation Format: Judy Y. Ou, Natalie Bennion, Kellee Parker, Douglas Fair, Heidi A. Hanson, Deanna Kepka, Echo L. Warner, Joemy M. Ramsay, Heydon K. Kaddas, Anne C. Kirchhoff. Risk factors, trends, and disparities in HPV-associated subsequent malignant neoplasms among adolescent and young adult cancer survivors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5763.

Earnings, Cohort Effects, and Inter‐Generational Inequality: Evidence From the Luxembourg Income Study

AbstractResearch suggests that inequalities between generations are most pronounced in the conservative European welfare states. However, it is likely that across all advanced capitalist societies superior earnings opportunities and steady employment are pursued at a later age due to secular labor market trends. In this paper, I examine the variation in generational inequalities across different regimes using data from the Luxembourg Income Study (LIS). The repeated cross‐sectional data allow me to trace the generational changes in income for eight countries, using both Age Period Cohort (APC) and synthetic cohort models. My results suggest that for most countries, cohorts born after 1980 have experienced lower entry‐level earning opportunities, relative to cohorts born between 1960 and 1980. However, synthetic cohort models suggest that while recent generations have suffered from successively worse entry positions, they appear to be “catching up,” which suggests that permanent “scarring effects” to lifetime earnings may not be inevitable.

Temporal Trends in the Incidence and Mortality of Major Reproductive-Related Cancers in Women in Guangzhou From 2010 to 2020: A Joinpoint and Age-Period-Cohort Study.

Objective: To understand the temporal trends of cancer incidence and mortality in women in Guangzhou during the past 11years and provide clues for future research. Methods: Data were obtained from the Guangzhou Cancer and Death Registry. Average annual percentage changes (AAPCs) in age-standardized incidence rates (ASIRs) and age-standardized mortality rates (ASMRs) were obtained by joinpoint regression. The age-period-cohort (APC) model was generated to quantify the effects of age, period, and cohort. Results: The ASIRs for cervical (AAPC = -4.3%) and ovarian (AAPC = -3.2%) cancers showed a downward trend during 2010-2020, and that for uterine cancer showed an upward trend. The ASMRs of breast (APC = 5.0%) and cervical (APC = 8.8%) cancers increased. The APC model highlights different age, period, and birth cohort effects depending on the cancer site. Conclusion: The ASIRs for cervical and ovarian cancers among women in Guangzhou showed a decreasing trend during the period. The APC model showed mortality for 4 cancers increased with age. Incidence and mortality decreased with increasing birth cohort. Annual reproductive cancer screening is recommended for women of appropriate age to reduce the disease burden.

Penalized smoothing splines resolve the curvature identifiability problem in age‐period‐cohort models with unequal intervals

Age-period-cohort (APC) models are frequently used in a variety of health and demographic-related outcomes. Fitting and interpreting APC models to data in equal intervals (equal age and period widths) is nontrivial due to the structural link between the three temporal effects (given two, the third can always be found) causing the well-known identification problem. The usual method for resolving the structural link identification problem is to base a model on identifiable quantities. It is common to find health and demographic data in unequal intervals, this creates further identification problems on top of the structural link. We highlight the new issues by showing that curvatures which were identifiable for equal intervals are no longer identifiable for unequal data. Furthermore, through extensive simulation studies, we show how previous methods for unequal APC models are not always appropriate due to their sensitivity to the choice of functions used to approximate the true temporal functions. We propose a new method for modeling unequal APC data using penalized smoothing splines. Our proposal effectively resolves the curvature identification issue that arises and is robust to the choice of the approximating function. To demonstrate the effectiveness of our proposal, we conclude with an application to UK all-cause mortality data from the Human mortality database.

Secular trends of suicide risk for residents in mainland China (2004 to 2019): An updated age–period–cohort analysis

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

Patterns of Birth Cohort‒Specific Smoking Histories in Brazil

Smoking prevalence has decreased considerably in Brazil from 34.8% in 1989 to 12.6% in 2019 owing to the implementation of strong tobacco control policies. However, recent data show that the downward trend may be stagnating. Detailed analyses of historical smoking patterns by birth cohort could guide tobacco control decision making in Brazil. Using the 2008 Global Adult Tobacco Survey and the 2013 and 2019 National Health Surveys, historical smoking patterns in Brazil were estimated, supplemented with data from the 2006‒2019 Surveillance System of Risk Factors for Chronic Diseases by Telephone Interviews. Age‒period‒cohort models with constrained natural splines were applied to estimate the annual probabilities of smoking initiation and cessation, current smoker prevalence, and mean cigarettes smoked per day by age, gender, and birth cohort. Analysis was conducted in 2021‒2022. Current smoker prevalence has declined considerably since the 1950 and 1955 birth cohorts for males and females, respectively, reflecting decreased smoking initiation and increased smoking-cessation probabilities over time. Among female cohorts born on or after 2000, smoking initiation may be increasing even as their smoking cessation has increased considerably. Mean cigarettes smoked per day has remained relatively constant across period and cohorts, showing only a minor decrease among males. These detailed cohort-specific smoking parameters can be used to inform models that evaluate the impact of tobacco use and policies on long-term health outcomes and guide public health decision making in Brazil. Stagnant mean cigarettes smoked per day, increasing female smoking initiation, and limited improvement in male cessation among recent cohorts present challenges to tobacco control.

Nasopharyngeal Carcinoma Burden and Its Attributable Risk Factors in China: Estimates and Forecasts from 1990 to 2050.

Nasopharyngeal carcinoma (NPC) is an uncommon and aggressive malignant head and neck cancer, which is highly prevalent in southern and southwestern provinces in China. The aim of this study was to examine the disease burden and risk factors of nasopharyngeal carcinoma in China from 1990 to 2019 and to predict the incidence trends from 2020 to 2049. All data were extracted from the 2019 Global Burden of Disease (GBD) study. Joinpoint regression and age-period-cohort (APC) models were chosen to analyze prevalence trends. The temporal trends and age distribution of risk factors were also analyzed descriptively. Bayesian APC models were used to predict the prevalence from 2020 to 2049. The results indicate a higher disease burden in men and older adults. Their attributable risk factors are smoking, occupational exposure to formaldehyde, and alcohol use. We predict that the incidence will be on the rise in all age groups between 2020 and 2049, with the highest incidence in people aged 70 to 89 years. In 2049, the incidence rate is expected to reach 13.39 per 100,000 (50-54 years), 16.43 (55-59 years), 17.26 (60-64 years), 18.02 (65-69 years), 18.55 (70-74 years), 18.39 (75-79 years), 19.95 (80-84 years), 23.07 (85-89 years), 13.70 (90-94 years), and 6.68 (95+ years). The findings of this study might deserve consideration in China's NPC prevention and control policy design.

A joinpoint and age–period–cohort analysis of ocular cancer secular trends in Iran from 2004 to 2016

Investigating secular trends of ocular cancer registration in Iran. After acquiring Iranian national population-based cancer registry data, trends of age-standardised incidence rates (ASIR) of ocular cancers and annual percent changes (APC) between 2004 and 2016 were analysed in age groups, gender, topography and morphology types with joinpoint regression analysis. Age, period, and cohort effects on incidence rates were estimated by age–period–cohort model. Geographic distribution of ASIR was assessed using GIS. Overall ASIR of ocular cancers was 16.04/100,000 (95% CI 15.77–16.32). Joinpoint regression analysis showed a significant increase of ASIR between 2004 and 2009 for males (APC = 5.5, 95% CI 0.9–10.2), ages over 50 years (APC = 5.2, 1.2–9.4), skin/canthus/adnexal cancers (APC = 4.2, 0.8–7.7), and carcinomas/adenocarcinomas (APC = 4.3, 0.6–8.1); however, between 2009 and 2016 a declining trend was observed in all investigated variables. ASIR of retinoblastoma was significantly increased (averaged APC = 20.7, 9–33.7) between 2004 and 2016. age–period–cohort analyses showed that incidence rates of ocular cancers significantly increased with aging, time periods, and birth cohort effects (p < 0.001). ASIR varied from 6.7/100,000 to 21.7/100,000 in Iran. Excepting retinoblastoma, all ocular cancer incidence trends were downward over a 13-year period; however, it was increasing between 2004 and 2009 cancer. ASIR was significant aging in Iran.

Patterns of Birth Cohort‒Specific Smoking Histories by Race and Ethnicity in the U.S.

U.S. smoking prevalence varies greatly by race/ethnicity. However, little is known about how smoking initiation, cessation, and intensity vary by birth cohort and race/ethnicity. Adult smoking data were obtained from the 1978-2018 National Health Interview Surveys. Age‒period‒cohort models with constrained natural splines were developed to estimate historical smoking patterns among non-Hispanic White, non-Hispanic Black, Hispanic, non-Hispanic Asian and Pacific Islander, and non-Hispanic American Indian and Alaskan Native individuals. Annual smoking prevalence and probabilities of smoking initiation, cessation, and intensity by age, year, gender, and race/ethnicity were estimated for the 1900 to 2000 birth cohorts. Analysis was conducted in 2020-2021. Smoking initiation probabilities were highest for the American Indian and Alaskan Native population, second highest among the non-Hispanic White population, and lowest among Asian and Pacific Islander and Hispanic populations across birth cohorts. Historically, initiation probabilities among non-Hispanic Black populations were comparable with those among non-Hispanic White populations but have decreased since the 1970 birth cohort. Cessation probabilities were lowest among American Indian and Alaskan Native and non-Hispanic Black populations and highest among non-Hispanic White and Asian and Pacific Islander populations across cohorts and ages. Initiation and cessation probabilities produce observed patterns of smoking where prevalence among American Indian and Alaskan Native populations is highest across all ages and cohorts. Across cohorts, smoking prevalence among non-Hispanic Black populations, particularly males, is lower than among non-Hispanic White populations at younger ages but higher at older ages. There are important and persistent racial/ethnic differences in smoking prevalence, initiation, cessation, and intensity across U.S. birth cohorts. Targeted interventions should address widening smoking disparities by race/ethnicity, particularly for American Indian and Alaskan Native and non-Hispanic Black populations.

Birth Cohort‒Specific Smoking Patterns by Family Income in the U.S.

In the U.S., low-income individuals generally smoke more than high-income individuals. However, detailed information about how smoking patterns differ by income, especially differences by birth cohort, is lacking. Using the National Health Interview Survey 1983-2018 data, individual family income was calculated as a ratio of the federal poverty level. Missing income data from 1983 to 1996 were imputed using sequential regression multivariate imputation. Age‒period‒cohort models with constrained natural splines were used to estimate annual probabilities of smoking initiation and cessation and smoking prevalence and intensity by gender and birth cohort (1900-2000) for 5 income groups: <100%, 100%-199%, 200%-299%, 300%-399%, and ≥400% of the federal poverty level. Analysis was conducted in 2020-2021. Across all income groups, smoking prevalence and initiation probabilities are decreasing by birth cohort, whereas cessation probabilities are increasing. However, relative differences between low- and high-income groups are increasing markedly, such that there were greater declines in prevalence among those in high-income groups in more recent cohorts. Smoking initiation probabilities are lowest in the ≥400% federal poverty level group for males across birth cohorts, whereas for females, this income group has the highest initiation probabilities in older cohorts but the lowest in recent cohorts. People living below the federal poverty level have the lowest cessation probabilities across cohorts. Smoking prevalence has been decreasing in all income groups; however, disparities in smoking by family income are widening in recent birth cohorts. Future studies evaluating smoking disparities should account for cohort differences. Intervention strategies should focus on reducing initiation and improving quit success among low-income groups.

Smoking Histories by State in the U.S.

Smoking rates across U.S. states have declined at different rates over time because some states have progressive tobacco control policies, whereas others have yet to adopt them. Therefore, each state has its own unique historical experience of smoking initiation, cessation, and prevalence. This study characterizes smoking histories for each U.S. state by birth cohort. Using 1965-2018 National Health Interview Survey and 1992-2019 Tobacco Use Supplement to the Current Population Survey data, statistical methods applied an age‒period‒cohort modeling framework to reconstruct population-level smoking histories for each state. Smoking initiation, cessation, and intensity by age, gender, and cohort were estimated for each state. These were used to construct state-specific trends in the prevalence of current, former, and never smoking as well as the mean smoking duration and pack years. Analysis was conducted from 2017 to 2022. California and Kentucky, respectively, are exemplar states of more and less aggressive tobacco control. Initiation probabilities were consistently lower in California than in Kentucky, and cessation probabilities were higher. Hence, the smoking prevalence derived from these parameters is higher in Kentucky. The intensity of cigarette smoking was higher in Kentucky than in California, yielding considerably higher estimated pack years when used with the other parameters. Summaries of smoking trends are given for all states. Smoking initiation, cessation, and intensity trends vary substantially across states, resulting in major differences in estimated smoking prevalence, duration, and pack years. Some states show improvements in smoking metrics over time with more recent birth cohorts, but others have shown very little.

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

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. 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. 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. 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.