• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5407-5409
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• 2014

Background: In National Cancer Registry Programme (NCRP) reports, various rates are routinely provided for 50 cancer sites of males and 54 cancer sites of females. Very often, depending on our interest, we wish to see these rates for group of cancers like head and neck cancers, oral cancers, and reproductive cancers. In such a situation, the desired rates are calculated independently from the actual data and reported. The question is can we derive the rates for groups of cancers from the published reports when the data is provided only for the individual sites? Objective: In the present paper, an attempt is made to explore the mathematical properties of various rates to derive them directly for the group of cancer sites from the published data when the rates are provided only for the individual sites. Source of data: The cancer incidence data collected by two urban Population Based Cancer Registries (PBCRs), under the network of NCRP for the period of 2006-08 was considered for the study purposes. The Registries included were: Bangalore and Bhopal. Results: In the present communication, we have shown that the crude rate (CR), age specific rates and age-adjuste rates (AAR) all possess additive properties. This means, given the above rates for individual sites, the above rates can be calculated for groups of sites by simply adding them. In terms of formula it can be stated that CR(Site1+Site2+++ SiteN) = CR(Site1)+CR(Site2) +++ CR(SiteN). This formula holds good for age specific rates as well as for AAR. This property facilitates the calculation of various rates for defined groups of cancers by simply adding the above rates for individual sites from which they are made up.

• Korea journal of population studies
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• v.29 no.2
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• pp.53-88
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• 2006

The major aim of this paper is to develop a hypothetical set of age-specific fertility rates which are logically derived and reasonably accurate in the projection of future population. The first procedure is to select a generalized log-gamma distribution model, which includes Coale-McNeil nuptiality model, in order to estimate and project a set of age-specific fertility rates by birth cohort and birth order. The second is to apply the log-gamma model with an empirical adjustment to the actual data to estimate and project the future fertility rates for relatively young birth cohorts who did not complete their reproductive career. This study reconstructs or translates a set of cohort age-specific fertility rates into a set of period age-specific fertility rates which must be hypothesized in order to establish the broader framework of future population projection. For example, the fertility at age 20 in the year of 2020 is the fertility at age 20 for the cohort born in 1990, while the fertility at age 21 in the year of 2020 is the fertility at 21 for the cohort born in 1989. In turn, once a set of age-specific fertility rates for the cohorts who were born up to the year of 2010, it is possible for one to establish an hypothetical set of period age-specific fertility rates which will be needed to project the future population until the year of 2055. The difference in the hypothetical system of age-specific fertility rates between this study and the 2005 special population projection comes from the fact that the fertility estimation/projection model used in this study was skillfully exploited to reflect better actual trend of fertility decline caused by rise in marriage age and increasing proportion of those who remain single until their end of reproduction. In this regard, this paper argues that the set of age-specific fertility rates derived from this study is more logical and reasonably accurate than the set of those used for the 2005 special projection. In the population projection, however, the fundamental issue of the hypothetical setting of age-specific fertility rates in relation to the fertility estimation/projection model is about how skillfully one can handle the period effects. It is not easy for one to completely cope with the problem of period effects except for the a minor period adjustment based on recent actual data, along with the given framework of a cohort-based fertility estimation/projection model.

• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.347-373
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• 2021

Over the past 50 years, explorative research on the nation's mortality decline patterns has showed a decrease in age-specific mortality rates in all age groups, but there were different improvement patterns in specific mortality rates depending on ages and periods. Greater distinct improvement was observed in mortality rates among women than men, and there was a noticeable improvement in mortality rates in certain groups especially in the more recent decades, revealing a structural change in the overall trends regarding death periods. In this paper, we compare various stochastic mortality models considering cohort effects for mortality projection using Korean female mortality data and further explore the uncertainty related to projection. It also created age-specific mortality rates and life expectancy for women until 2067 based on the results of the analysis, and compared them with future age-specific mortality rates and life expectancy provided by the national statistical office (KOISIS). The best optimal model could vary depending on data usage periods. however, considering the overall fit and predictability, the PLAT model would be regarded to have appropriate predictability in terms of the mortality rates of women in South Korea.

• Communications for Statistical Applications and Methods
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• v.28 no.2
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• pp.119-134
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• 2021

Lung cancer is one of the leading causes of cancer deaths in the world. Investigation of mortality rates is pivotal to adequately understand the determinants causing this disease, allocate public health resources, and apply different control measures. Our study aims to analyze and forecast age-specific US lung cancer mortality trends. We report functions of mortality rates for different age groups by incorporating functional principal component analysis to understand the underlying mortality trend with respect to time. The mortality rates of lung cancer have been higher in men than in women. These rates have been decreasing for all age groups since 1990 in men. The same pattern is observed for women since 2000 except for the age group 85 and above. No significant changes in mortality rates in lower age groups have been reported for both gender. Lung cancer mortality rates for males are relatively higher than females. Ten-year predictions of mortality rates depict a continuous decline for both gender with no apparent change for lower age groups (below 40).

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2461-2464
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• 2014

Background: Cancer accounts for 12.6% of total deaths in the world (just after heart disease). Materials and Methods: Frequency and age-specific incidence rates of breast and gynecologic cancers in Iran are calculated based on the dataset of the National Cancer Registry of Iran in 2005. Results: Gynecologic and breast cancer accounted for 7.6% and 25.6% of total cancer cases, respectively. Ovarian cancer was the most frequent gynecologic cancer followed by endometrium. Endometrial cancer revealed the highest age specific incidence rate followed by ovary (after 59 years). Conclusions: Regarding disease burden, breast and gynecologic cases account for 33.4% of total cancer patients. The age specific incidence rate is a useful guide in epidemiologic and future plans.

• Journal of Preventive Medicine and Public Health
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• v.52 no.2
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• pp.123-130
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• 2019

Objectives: The aim of this study was to evaluate the impact of shifts in maternal age and parity on the increasing trends in the low birth weight (LBW) and very low birth weight (VLBW) rates from 2005 to 2015 in South Korea. Methods: Data from 4 993 041 live births registered with Statistics Korea during the period between 2005 and 2015 were analyzed. Applying a modified standardization method, we partitioned the total increment in the LBW and VLBW rates into (1) the increase in the LBW and VLBW rates due to changes in the maternal age and parity distribution (AP-dis) and (2) the increase due to changes in the age-specific and parity-specific rates (AP-spe) of LBW and VLBW for singleton and multiple births, respectively. Results: During the study period, the total increment in the LBW and VLBW rates was 1.43%p and 0.25%p, respectively. Among singleton births, changes in the AP-dis accounted for 79% (0.34%p) and 50% (0.06%p) of the total increment in the LBW and VLBW rates, respectively. Meanwhile, among multiple births, changes in the AP-dis did not contribute to the increase in the LBW and VLBW rates, with 100% of the increase in the LBW (1.00%p) and VLBW (0.13%p) rates being attributed to changes in the AP-spe. Conclusions: This study demonstrated that shifts in maternal age and parity were prominent contributors to the increase in the LBW and VLBW rates among singleton births between 2005 and 2015 in South Korea.

• Korea journal of population studies
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• v.32 no.1
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• pp.1-23
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• 2009

This paper uses a survey data to analyze the age-specific fertility rates, age-specific cumulative fertility rates, and ages of marriage of the five birth cohorts of Korean women born in the 1940s and thereafter. It was found that later cohorts reach their highest age-specific fertility rate at higher ages than earlier cohorts. The age-specific cumulative fertility rates of the 1950s and 1960 cohorts were found to be much lower than those of the immediately preceding cohorts, while those of the 1970s and 1980s cohorts were not different from those of the 1960s cohorts. Women belonging to later cohorts were found to get married at relatively higher ages. The estimation results of the hazard model show that women belonging to later cohorts and those with more schooling have a tendency to get married at higher ages. The effect of the birth cohorts is thought to be due to the economic, social, and cultural changes in Korea during the late 50 years or so. The time interval between a woman‘s marriage and first birth was found not to be affected by either the year of marriage or that of her birth. Also, those who remained employed for some time around their marriage and those with low schooling were found to have a lower first child birth hazard, which implies that married women’s employment status and family income play an important role in their decisions on childbirth.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9731-9737
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• 2014

Large scale secular registry or surveillance systems have been accumulating vast data that allow mathematical modeling of cancer incidence and mortality rates. Most contemporary models in this regard use time series and APC (age-period-cohort) methods and focus primarily on predicting or analyzing cancer epidemiology with little attention being paid to implications for designing cancer registry, surveillance or evaluation initiatives. This research models age-specific cancer incidence rates using logistic growth equations and explores their performance under different scenarios of data completeness in the hope of deriving clues for reshaping relevant data collection. The study used China Cancer Registry Report 2012 as the data source. It employed 3-parameter logistic growth equations and modeled the age-specific incidence rates of all and the top 10 cancers presented in the registry report. The study performed 3 types of modeling, namely full age-span by fitting, multiple 5-year-segment fitting and single-segment fitting. Measurement of model performance adopted adjusted goodness of fit that combines sum of squred residuals and relative errors. Both model simulation and performance evalation utilized self-developed algorithms programed using C# languade and MS Visual Studio 2008. For models built upon full age-span data, predicted age-specific cancer incidence rates fitted very well with observed values for most (except cervical and breast) cancers with estimated goodness of fit (Rs) being over 0.96. When a given cancer is concerned, the R valuae of the logistic growth model derived using observed data from urban residents was greater than or at least equal to that of the same model built on data from rural people. For models based on multiple-5-year-segment data, the Rs remained fairly high (over 0.89) until 3-fourths of the data segments were excluded. For models using a fixed length single-segment of observed data, the older the age covered by the corresponding data segment, the higher the resulting Rs. Logistic growth models describe age-specific incidence rates perfectly for most cancers and may be used to inform data collection for purposes of monitoring and analyzing cancer epidemic. Helped by appropriate logistic growth equations, the work vomume of contemporary data collection, e.g., cancer registry and surveilance systems, may be reduced substantially.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7281-7285
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• 2014

Background: Gastric cancer is the second most common gastrointestinal cancer and is more common in the East, compared to the West. This study assesses the trend of gastric cancers in Brunei Darussalam, a developing nation with a predominantly Malay population. Materials and Methods: The cancer registry from 1986 to 2012 maintained by the Department of Pathology, the only State Laboratory at the RIPAS Hospital, Ministry of Health, was reviewed and data extracted for analyses. The age standardised rate (ASR) and age specific incidence rate were calculated based on the projected population. Cancers diagnosed below 45 years were categorised as young gastric cancer. Results: Over the study period, there were a total of 551 cases of gastric cancer diagnosed. The most common type was adenocarcinoma (87.9%), followed by lymphoma (6.1%) and gastrointestinal stromal tumour (2.8%). The overall mean age at diagnosis was 61.9 years old (range 15 to 98) with an increasing trend observed, but this was not significant (ANOVA). There were differences in the mean age at diagnosis for the different races (p=0.003 for trend), but not the gender (p=0.105). Young gastric cancer accounted for 14.9%, being more common in women, and in Expatriate and Malay populations compared to the Chinese. There was a decrease in the ASR, from 17.3/100,000 in 1986-1990 to 12.5/100,000 in 2006-2010. Chinese had a higher overall ASR (20.2/100,000) compared to the Malays (11.8/100,000). The age specific rates were comparable between men and women until the age group 55-59 years when the rates started to diverge, becoming higher in men. Chinese men had higher rates then Malay men whereas, the rates were higher or comparable between the women until the age group >70 when the rate for Chinese women overtook their Malay counterpart. Conclusions: Our study showed that there is a declining trend in the incidence of gastric cancer and higher rates were observed in men and Chinese.

• Journal of Korean Academy of Nursing
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• v.37 no.1
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• pp.44-51
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• 2007

Purpose: The purpose of this study was to compare suicide mortality by region in South Korea. Method: Suicide mortality differentials were calculated for several mortality indicators by geographical regions from raw data of the cause of death from KNSO. Results: The results are as follows; the Crude suicide death rate was 22.63 per 100,000. The highest was in Kangwon showing 37.84% whereas, Chungnam, and Jeonbuk followed after. Suicide was 4.4% of all causes of death, but Inchon and Ulsan showed a higher proportion. The male suicide death rate was 31.12 per 100,000 and females 14.09. The ratio of gender suicide mortality was 2.21, per 100,000 and was the highest in Jeju. For age-specific suicide death rates, the rate increased as age advanced, showing 2.33 per 100,000 in 0-19years, 18.68 in 20-39, 30.48 in 40-59, 63.33 in 60 years and over. In Ulsan, Kangwon, and Inchon, age-specific suicide death rates of the 60 and over age group were higher than other regions, Daegu, Busan, and Kangwon showed a higher age-specific suicide mortality of the 40-59 age group, and Kangwon, Jeonnam, and Chungnam had a higher age-specific suicide mortality of the 20-39 age group. Conclusions: Suicide mortality differed by region. These results can be used for a regional health care plan and planning for suicide prevention by regions.