• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8589-8594
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• 2016

Background: Liver cancer is one of the most common causes of death in the world. In Korea, hepatitis B virus (HBV) is a major risk factor for liver cancer but infection rates have been declining since the implementation of the national vaccination program. In this study, we examined the secular trends in liver cancer mortality to distinguish the effects of age, time period, and birth cohort. Materials and Methods: Data for the annual number of liver cancer deaths in Korean adults (30 years and older) were obtained from the Korean Statistical Information Service for the period from 1984-2013. Joinpoint regression analysis was used to study the shapes of and to detect the changes in mortality trends. Also, an age-period-cohort model was designed to study the effect of each age, period, and birth cohort on liver cancer mortality. Results: For both men and women, the age-standardized mortality rate for liver cancer increased from 1984 to 1993 and decreased thereafter. The highest liver cancer mortality rate has shifted to an older age group in recent years. Within the same birth cohort group, the mortality rate of older age groups has been higher than in the younger age groups. Age-period-cohort analysis showed an association with a high mortality rate in the older age group and in recent years, whereas a decreasing mortality rate were observed in the younger birth cohort. Conclusions: This study confirmed a decreasing trend in liver cancer mortality among Korean men and women after 1993. The trends in mortality rate may be mainly attributed to cohort effects.

• Journal of Preventive Medicine and Public Health
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• v.53 no.3
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• pp.198-204
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• 2020

Objectives: This study aimed to analyze the mortality of heart disease (HD), ischemic heart disease (IHD), and cerebrovascular disease (CeVD) through an age-period-cohort (APC) analysis. Methods: We used data on mortality due to cardiovascular disease from 1995 to 2018 in Japan, as determined by Vital Statistics. Age groups from 0 years to 99 years were defined by 5-year increments, and cohorts were defined for each age group of each year with a 1-year shift. We used Bayesian APC analysis to decompose the changes in the diseases' mortality rates into age, period, and cohort effects. Results: The period effects for all diseases decreased during the analyzed periods for both men and women. The cohort effects for men increased substantially in cohorts born from around 1940 to the 1970s for all types of cardiovascular diseases. The cohort effects of HD decreased in the cohorts born in the 1970s or later for both men and women. Regarding IHD and CeVD, either a non-increase or decrease of cohort effects was confirmed for cohorts born in the 1970s or later for men, but the effects for women showed a continuously increasing trend in the cohorts born in the 1960s or later. Conclusions: The cohort effects for IHD and CeVD showed increasing trends in younger generations of women. This suggests that preventive approaches against cardiovascular diseases are needed, particularly for women.

• Health Policy and Management
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• v.28 no.4
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• pp.378-391
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• 2018

Background: People who were born in different years, that is, different birth cohorts, grow in varying socio-historical and dynamic contexts, which result in differences in social dispositions and physical abilities. Methods: This study used age-period-cohort analysis method to establish explanatory models on healthcare expenditure in Korea reflecting birth cohort factor using intrinsic estimator. Based on these models, we tried to investigate the effects of ageing population on future healthcare expenditure through simulation by scenarios. Results: Coefficient of cohort effect was not as high as that of age effect, but greater than that of period effect. The cohort effect can be interpreted to show 'healthy ageing' phenomenon. Healthy ageing effect shows annual average decrease of -1.74% to 1.57% in healthcare expenditure. Controlling age, period, and birth cohort effects, pure demographic effect of population ageing due to increase in life expectancy shows annual average increase of 1.61%-1.80% in healthcare expenditure. Conclusion: First, since the influence of population factor itself on healthcare expenditure increase is not as big as expected. Second, 'healthy ageing effect' suggests that there is a need of paradigm shift to prevention centered-healthcare services. Third, forecasting of health expenditure needs to reflect social change factors by considering birth cohort effect.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3951-3955
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• 2015

Background: Colorectal cancer mortality has started to decrease in several developed countries in Asia. The current study aimed to present the long-term trends in colorectal cancer mortality in Korea using joinpoint analysis and age-period-cohort modeling. Materials and Methods: The number of colorectal cancer deaths and the population for each 5-year age group were obtained from Statistics Korea for the period 1984-2013 for adults 30 years and older. Joinpoint regression analysis was conducted to determine changes in trends in age-standardized mortality rates, and age-period-cohort analysis was performed to describe trends in colorectal cancer mortality using the intrinsic estimator method. Results: In men, the age-standardized mortality rate for colorectal cancer increased from 1984 to 2003, and the mortality rates stabilized thereafter, whereas the mortality rate of colorectal cancer in women has decreased since 2004. The age-specific mortality rate of colorectal cancer increased in both men and women over time, whereas decreases in the age-specific mortality rate in younger cohorts were observed. In the age-period-cohort analysis, old age and recent period were associated with higher mortality for both men and women. The birth cohort born after 1919 showed reduced colorectal cancer mortality in both men and women. Conclusions: Our study showed a recent decreasing trend in colorectal cancer mortality in women and a stable trend in men after 2003-2004. These changes in colorectal cancer mortality may be attributed to birth cohort effects.

• Journal of Preventive Medicine and Public Health
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• v.53 no.6
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• pp.409-418
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• 2020

Objectives: This study conducted an age-period-cohort (APC) analysis of trends in healthy lifestyle behaviors in Japan. Methods: We used National Health and Nutrition Survey data on salt intake and prevalence of smoking, drinking, and physical activity between 1995 and 2018 in Japan. Age groups were defined from 20 years to 69 years old in 10-year increments. Cohorts were defined for each age group of each year with a 1-year shift, and cohorts born in 1926-1935 (first cohort) until 1989-1998 (last cohort) were examined. We conducted a Bayesian APC analysis, calculating estimated values for each behavior by age group, period, and cohort. Results: Estimated salt intake decreased from cohorts born in the 1930s to the 1960s, but increased thereafter in both genders, and the magnitude of increase was larger for men. Estimated smoking prevalence increased in the cohorts starting from the 1930s for men and the 1940s for women, and then decreased starting in the cohorts born in the 1970s for both genders. Although estimated drinking prevalence decreased starting in the cohorts born in approximately 1960 for men, for women it increased until the cohorts born in approximately 1970. Estimated physical activity prevalence decreased starting in the cohorts born in the 1940s in both genders, but the magnitude of decrease was larger for women. Conclusions: Trends in cohort effects differed by gender, which might be related to changes in the social environment for women. Improvements in dietary and exercise habits are required in more recently born cohorts of both genders.

• Journal of Preventive Medicine and Public Health
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• v.45 no.5
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• pp.323-328
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• 2012

Objectives: Economic growth and development of medical technology help to improve the average life expectancy, but the western diet and rapid conversions to poor lifestyles lead an increasing risk of major chronic diseases. Coronary heart disease mortality in Korea has been on the increase, while showing a steady decline in the other industrialized countries. An age-period-cohort analysis can help understand the trends in mortality and predict the near future. Methods: We analyzed the time trends of ischemic heart disease mortality, which is on the increase, from 1985 to 2009 using an age-period-cohort model to characterize the effects of ischemic heart disease on changes in the mortality rate over time. Results: All three effects on total ischemic heart disease mortality were statistically significant. Regarding the period effect, the mortality rate was decreased slightly in 2000 to 2004, after it had continuously increased since the late 1980s that trend was similar in both sexes. The expected age effect was noticeable, starting from the mid-60's. In addition, the age effect in women was more remarkable than that in men. Women born from the early 1900s to 1925 observed an increase in ischemic heart mortality. That cohort effect showed significance only in women. Conclusions: The future cohort effect might have a lasting impact on the risk of ischemic heart disease in women with the increasing elderly population, and a national prevention policy is need to establish management of high risk by considering the age-period-cohort effect.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.2
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• pp.166-181
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• 2020

This paper attempts to compare and analyze the intensity, trend, and regional gap of income inequality, capitalizing upon the Age-Period-Cohort model which considers age, time and cohort effects, with the 1998-2018 Korea Labor Panel (KLIPS) survey data for respondents living in the Capital and Non-Capital Regions. The main analysis results are as follows. First, in the case of both cohort and age effects, those in their 50~60s, including the so-called baby boomers and '386 generation' living in the Capital Region, have relatively lower income inequality effect compared to that of other age groups and cohorts in the Non-Capital Region. Second, the micro-individual characteristics cannot be ignored to account for a regional gap in income inequality, but rather the effects of structural and institutional omitted variables and the social discrimination effects of individual characteristics variables are more significant in explaining it. Overall, intra-and inter-cohort income inequalities appear to overlap.

• Human Ecology Research
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• v.57 no.1
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• pp.51-71
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• 2019

This study analyzed the poverty rate by poverty dimension, correlation between multidimensional poverty, variables that affected the number of poverty dimension and the probability of the poor or not. The sample consisted of 6,361 elderly households (1,561 baby boom birth cohort, 1,793 post-liberation birth cohort, 3,007 Japanese colonial period birth cohort) taken from the $12^{th}$ Korean Welfare Panel Study. First, the highest poverty rate among the baby boom birth cohort was 62.8% of employment poverty. The highest rate among the post-liberation birth cohort and Japanese colonial period birth cohort, was 82.5%, 92.3% of health poverty, respectively. Second, the highest coefficient in the baby boom birth cohort was .354 for asset poverty and relation poverty. In the remaining two cohorts, the coefficient for asset poverty and relation poverty was the highest at .268, .284, respectively. Third, the average number of poverty dimensions was 2.318 of the baby boom birth cohort, 2.921 of the post-liberation birth cohort, 3.564 of the poverty in the Japanese colonial period birth cohort. Also, the poverty rate for each cohort was 20.179%, 28.779%, and 50.083%, respectively. Fourth, the significant variables in all cohorts were gender, education, marital status, residence, and equalized ordinary income for the multiple regression analysis on the number of poverty dimensions. Additionally, age of the post-liberation birth cohort was significant, age and family numbers of the Japanese colonial period birth cohort were significant. Significant variables in logistic analysis on the probability of poverty or not were the same as those of regression analysis.

• Journal of Preventive Medicine and Public Health
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• v.52 no.3
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• pp.188-194
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• 2019

Objectives: Outbreaks of scarlet fever in Mexico in 1999, Hong Kong and mainland China in 2011, and England in 2014-2016 have received global attention, and the number of notified cases in Korean children, including in Jeju Province, has also increased since 2010. To identify relevant hypotheses regarding this emerging outbreak, an age-period-cohort (APC) analysis of scarlet fever incidence was conducted among children in Jeju Province, Korea. Methods: This study analyzed data from the nationwide insurance claims database administered by the Korean National Health Insurance Service. The inclusion criteria were children aged ${\leq}14years$ residing in Jeju Province, Korea who received any form of healthcare for scarlet fever from 2002 to 2016. The age and year variables were categorized into 5 groups, respectively. After calculating the crude incidence rate (CIR) for age and calendar year groups, the intrinsic estimator (IE) method was applied to conduct the APC analysis. Results: In total, 2345 cases were identified from 2002 to 2016. Scarlet fever was most common in the 0-2 age group, and boys presented more cases than girls. Since the CIR decreased with age between 2002 and 2016, the age and period effect decreased in all observed years. The IE coefficients suggesting a cohort effect shifted from negative to positive in 2009. Conclusions: The results suggest that the recent outbreak of scarlet fever among children in Jeju Province might be explained through the cohort effect. As children born after 2009 showed a higher risk of scarlet fever, further descriptive epidemiological studies are needed.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3893-3898
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• 2012

In previous studies we predicted future trends in cancer incidence for each prefecture in order to plan cancer control. Those predictions, however, did not take into account the characteristics of each prefecture. We therefore used the results of age-period-cohort analysis of incidence and mortality data of Osaka, and estimated the incidence and mortality of cancers at all sites and selected sites. The results reflect the characteristics of Osaka, which has and is expected to have large number of patients with liver cancer. We believe our results to be useful for planning and evaluating cancer control activities in Osaka. It would be worthwhile to base the estimation of cancer incidence and mortality in each prefecture on each population-based cancer registry.