• Title/Summary/Keyword: Cohort effect

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가계 식품수요 요인의 계량분석 - 한국과 일본의 비교 - (Econometric Analysis on Factors of Food Demand in the Household : Comparative Study between Korea and Japan)

  • 조광현
    • 한국식생활문화학회지
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    • 제14권4호
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    • pp.371-383
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    • 1999
  • 본 논문은 한일 양국의 가계에 있어서의 식품수요에 미치는 요인을 파악하기 위해서 종래의 수요모델에 코호트(cohort, 행동을 같이 한 집합체) 분석적인 생각을 도입하여 한일 양국의 식품수요 형태분석을 하였다. 여기에 제시한 새로운 수요분석 모델은 소비지출과 가격이 식료수요에 미치는 경제적 효과 이외에 세대주 연령효과나 출생연도와 같은 비경제적효과 등도 계량한 것이 특징이다. 분석한 결과를 요약하면 다음과 같다. 1. 한일 양국의 식품수요의 품목군별 탄력성을 보면 유지류, 음료, 조리식품의 수요탄력성은 한국보다 일본이 더 탄력적이었지만, 다른 모든 품목은 일본보다 한국이 탄력적이었다. 곡류, 육류, 외식의 외부화 식품의 소비지출과 가격탄력성은 한국의 큰 품목과 일본의 큰 품목이 서로 상충하고 있어서 일정한 경향 파악이 곤란하다. 그러나 신선식품에 대한 소비지출과 가격의 탄력성은 모두 일본보다 한국이 크다. 2. 식품에 대한 지출액은 세대 구성원의 연령을 반영하여 비교하여 볼 때 한국과 일본의 결과가 비슷하였다. 즉 세대주 연령이 젊은 계층의 가족에는 유아가 있기 때문에 유란류의 지출액이, 또한 중년층에서는 청소년이 많기 때문에 과자류의 지출액이 다른 연령계층에 비하여 많았다. 한국은 연령계층이 높을수록 2세대 가족이 많기 때문에 다수 품목에 지출액이 많고, 일본의 중년층은 과자류를 포함하여 특히 곡류, 육류 등의 에너지 식품이나 외식의 지출액이 많다. 그러나 연령이 높은 계층에서는 세대 구성원이 거의 성인이며 평균연령이 높기 때문에 곡류, 육류, 외식 등의 지출액이 적었지만 어패류, 야채류 등의 전통식품이나 조리식품의 지출이 많았다. 3. 식품소비의 패턴은 세대주 출생연도별로 비교하면 한일 양국 모두 구세대일수록 주식 중시의 경향을 나타내고 신세대일수록 축산물, 유지류, 외부화 식품의 비중이 높았다. 그러나 품목 구성의 세대간 차이는 한국에 있어서는 매우 크지만 일본의 경우는 비교적 작았다. 따라서 식생활의 서구화, 외부화는 세대교체에 동반하여 한국에는 급속히 진행하지만 일본은 점진적으로 진행한다고 볼 수 있다. 4. 가계 식품 수요의 장기 변화에 미치는 요인은 소비지출, 가격, 세대주 출생연도, 연령 등의 네 가지 요인으로 나누어서 각각의 효과를 요인간으로 비교하면 한일 양국이 함께 가격의 효과가 가장 작다. 그러나 그 이외 요인별 효과의 상대적 중요성은 양국간에 다른데 한국은 소비지출의 효과가 출생연도나 연령 효과보다 크지만 일본은 경제적 요인인 소비지출보다 세대주의 출생연도나 연령 등의 비경제적 요인의 효과가 크다.

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Re-examination of Opisthorchis viverrini Infection in Northeast Thailand

  • Yeoh, Kheng-Wei;Promthet, Supannee;Sithithaworn, Paiboon;Kamsaard, Supot;Parkin, Donald Maxwell
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3413-3418
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    • 2015
  • Background: Liver fluke infection caused by the parasite Opisthorchis viverrini (O. viverrini), a human carcinogen, is endemic in north-eastern Thailand and remains a major health problem. Objectives: The objectives of the study were to (1) resurvey the prevalence of O. viverrini infection in a field site from the Khon Kaen Cohort Study (in newly recruited subjects as well as previous cohort subjects surveyed in 1992); (2) investigate how subjects' lifestyle habits and their exposure to health promotion initiatives influence changes in prevalence of O. viverrini infection. Materials and Methods: The prevalence of O. viverrini infection in the cohort subjects (as well as new subjects) was investigated using faecal egg counts. Information on demographic factors, lifestyle and awareness of health promotion initiatives were obtained through questionnaires. Results: O. viverrini infection rates in the same individuals of the cohort were lower in 2006 than in 1992. Also, by studying the period effect, the current 35-44 year olds had a 12.4% (95% CI 3.9% to 20.9%) lower prevalence of O. viverrini infection than the 35-44 year olds in 1992 (24.2% versus 11.8%). Lifestyle choices showed that smoking and alcohol consumption were associated with an increased chance of acquiring O. viverrini infection with adjusted odds ratios of 10.1 (95%CI 2.4-41.6) and 5.3 (95%CI 1.2-23.0), respectively. Conclusions: Our study has demonstrated that although the prevalence of O. viverrini infection over a 14-year period has decreased, unhealthy lifestyle was common with smoking and alcohol consumption being associated with increased chances of infection, emphasising the double burden of disease which developing countries are facing.

Depression and the Risk of Breast Cancer: A Meta-Analysis of Cohort Studies

  • Sun, Hui-Lian;Dong, Xiao-Xin;Cong, Ying-Jie;Gan, Yong;Deng, Jian;Cao, Shi-Yi;Lu, Zu-Xun
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3233-3239
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    • 2015
  • Background: Whether depression causes increased risk of the development of breast cancer has long been debated. We conducted an updated meta-analysis of cohort studies to assess the association between depression and risk of breast cancer. Materials and Methods: Relevant literature was searched from Medline, Embase, Web of Science (up to April 2014) as well as manual searches of reference lists of selected publications. Cohort studies on the association between depression and breast cancer were included. Data abstraction and quality assessment were conducted independently by two authors. Random-effect model was used to compute the pooled risk estimate. Visual inspection of a funnel plot, Begg rank correlation test and Egger linear regression test were used to evaluate the publication bias. Results: We identified eleven cohort studies (182,241 participants, 2,353 cases) with a follow-up duration ranging from 5 to 38 years. The pooled adjusted RR was 1.13(95% CI: 0.94 to 1.36; $I^2=67.2%$, p=0.001). The association between the risk of breast cancer and depression was consistent across subgroups. Visual inspection of funnel plot and Begg's and Egger's tests indicated no evidence of publication bias. Regarding limitations, a one-time assessment of depression with no measure of duration weakens the test of hypothesis. In addition, 8 different scales were used for the measurement of depression, potentially adding to the multiple conceptual problems concerned with the definition of depression. Conclusions: Available epidemiological evidence is insufficient to support a positive association between depression and breast cancer.

HbA1c changes in patients with diabetes following periodontal therapy

  • Kim, Su-Hwan;Lee, Jihye;Kim, Won-Kyung;Lee, Young-Kyoo;Kim, Young-Sung
    • Journal of Periodontal and Implant Science
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    • 제51권2호
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    • pp.114-123
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    • 2021
  • Purpose: This retrospective cohort study aimed to assess the effect of nonsurgical periodontal therapy on glycated hemoglobin (HbA1c) levels in patients with both type 2 diabetes and chronic periodontitis. Methods: The intervention cohort (IC) comprised 133 patients with type 2 diabetes who received nonsurgical periodontal treatment, while the matching cohort (MC) included 4787 patients with type 2 diabetes who visited the Department of Endocrinology and Metabolism of Asan Medical Center. The patients in each cohort were divided into 3 groups according to their baseline HbA1c level: subgroup 1, HbA1c <7%; subgroup 2, 7%≤ HbA1c <9%; and subgroup 3, HbA1c ≥9%. Changes in HbA1c levels from baseline to 6 and 12 months were analyzed. In addition, the association between changes in HbA1c levels and the number of periodontal maintenance visits was investigated. Results: There were no statistically significant changes in HbA1c levels in the IC and MC or their subgroups when evaluated with repeated-measures analysis of variance. However, the IC showed maintenance of baseline HbA1c levels, while the MC had a trend for HbA1c levels to steadily increase as shown by pairwise comparisons (baseline to 6 months and baseline to 12 months). IC subgroup 1 also maintained steady HbA1c levels from 6 months to 12 months, whereas MC subgroup 1 presented a steady increase during the same period. The number of periodontal maintenance visits had no association with changes in HbA1c levels during the 1-year study duration. Conclusions: For patients with both type 2 diabetes and periodontitis, nonsurgical periodontal treatment and periodontal maintenance may help to control HbA1c levels.

Association Between Angiotensin II Receptor Blockers and the Risk of Lung Cancer Among Patients With Hypertension From the Korean National Health Insurance Service-National Health Screening Cohort

  • Moon, Sungji;Lee, Hae-Young;Jang, Jieun;Park, Sue K.
    • Journal of Preventive Medicine and Public Health
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    • 제53권6호
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    • pp.476-486
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    • 2020
  • Objectives: The objective of this study was to estimate the risk of lung cancer in relation to angiotensin II receptor blocker (ARB) use among patients with hypertension from the Korean National Health Insurance Service-National Health Screening Cohort. Methods: We conducted a retrospective cohort study of patients with hypertension who started to take antihypertensive medications and had a treatment period of at least 6 months. We calculated the weighted hazard ratios (HRs) and their 95% confidence intervals (CIs) of lung cancer associated with ARB use compared with calcium channel blocker (CCB) use using inverse probability treatment weighting. Results: Among a total of 60 469 subjects with a median follow-up time of 7.8 years, 476 cases of lung cancer were identified. ARB use had a protective effect on lung cancer compared with CCB use (HR, 0.75; 95% CI, 0.59 to 0.96). Consistent findings were found in analyses considering patients who changed or discontinued their medication (HR, 0.50; 95% CI, 0.32 to 0.77), as well as for women (HR, 0.56; 95% CI, 0.34 to 0.93), patients without chronic obstructive pulmonary disease (HR, 0.75; 95% CI, 0.56 to 1.00), never-smokers (HR, 0.64; 95% CI, 0.42 to 0.99), and non-drinkers (HR, 0.69; 95% CI, 0.49 to 0.97). In analyses with different comparison antihypertensive medications, the overall protective effects of ARBs on lung cancer risk remained consistent. Conclusions: The results of the present study suggest that ARBs could decrease the risk of lung cancer. More evidence is needed to establish the causal effect of ARBs on the incidence of lung cancer.

국민건강보험공단 표본코호트 DB를 이용한 스케일링 보험급여화 전후 실태조사 (Evaluation of national health insurance coverage of periodontal scaling: A nationwide cohort study in Korea)

  • 김영택;이재홍;권혜인;이중석;최정규;김동욱;최성호
    • 대한치과의사협회지
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    • 제54권8호
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    • pp.604-612
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    • 2016
  • The aim of this study was to evaluate the effect of national health insurance coverage of periodontal scaling using the National Health Insurance Service-National Sample Cohort for 2009-2013. After the enforcement of periodontal scaling covered by national health insurance, the number of patients diagnosed with periodontal disease and received treatment, has increased from 35,234 to 99,576 people in the last 4 years. Further, the number of patients who received the treatment of periodontal disease more than once, have also increased to around 69% in 2013 when compared to 2012. Moreover, the number of patients receiving periodontal scaling has been steadily increasing every year. Among the patients who visited hospital for periodontal disease, there has been an increase of 280%. As a result, continuous public relations and long-term research on the effect of periodontal scaling as a prophylactic treatment is necessary.

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코호트 기반 조사 공변수 자료의 신뢰도 평가 연구: 원전주변지역주민 역학조사연구 (Reliability of Covariates in Baseline Survey of a Cohort Study: Epidemiological Investigation on Cancer Risk Among Residents Who Reside Near the Nuclear Power Plants in Korea)

  • 배상혁;박보영;이충민;안윤옥
    • Journal of Preventive Medicine and Public Health
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    • 제43권2호
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    • pp.159-165
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    • 2010
  • Objectives: We evaluated the reliability of the possible covariates of the baseline survey data collected for the Epidemiological Investigation on Cancer Risk Among Residents Who Reside Near the Nuclear Power Plants in Korea. Methods: Follow-up surveys were conducted for 477 participants of the cohort at less than 1 year after the initial survey. The mean interval between the initial and follow-up surveys was 282.5 days. Possible covariates were identified by analyzing the correlations with the exposure variable and associations with the outcome variables for all the variables. Logistic regression analysis with stepwise selection was further conducted among the possible covariates to select variables that have covariance with other variables. We considered that these variables can be representing other variables. Seven variables for the males and 3 variables for the females, which had covariance with other possible covariates, were selected as representative variables. The Kappa index of each variable was calculated. Results: For the males, the Kappa indexes were as follow; family history of cancer was 0.64, family history of liver diseases in parents and siblings was 0.56, family history of hypertension in parents and siblings was 0.51, family history of liver diseases was 0.50, family history of hypertension was 0.44, a history of chronic liver diseases was 0.53 and history of pulmonary tuberculosis was 0.36. For females, the Kappa indexes were as follow; family history of cancer was 0.58, family history of hypertension in parents and siblings was 0.56 and family history of hypertension was 0.47. Conclusions: Most of the possible covariates showed good to moderate agreement.

Relationship Between Non-alcoholic Fatty Liver Disease and Decreased Bone Mineral Density: A Retrospective Cohort Study in Korea

  • Sung, Jisun;Ryu, Seungho;Song, Yun-Mi;Cheong, Hae-Kwan
    • Journal of Preventive Medicine and Public Health
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    • 제53권5호
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    • pp.342-352
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    • 2020
  • Objectives: The aim of this retrospective cohort study was to investigate whether non-alcoholic fatty liver disease (NAFLD) was associated with incident bone mineral density (BMD) decrease. Methods: This study included 4536 subjects with normal BMD at baseline. NAFLD was defined as the presence of fatty liver on abdominal ultrasonography without significant alcohol consumption or other causes. Decreased BMD was defined as a diagnosis of osteopenia, osteoporosis, or BMD below the expected range for the patient's age based on dual-energy X-ray absorptiometry. Cox proportional hazards models were used to estimate the hazard ratio of incident BMD decrease in subjects with or without NAFLD. Subgroup analyses were conducted according to the relevant factors. Results: Across 13 354 person-years of total follow-up, decreased BMD was observed in 606 subjects, corresponding to an incidence of 45.4 cases per 1000 person-years (median follow-up duration, 2.1 years). In the model adjusted for age and sex, the hazard ratio was 0.65 (95% confidence interval, 0.51 to 0.82), and statistical significance disappeared after adjustment for body mass index (BMI) and cardiometabolic factors. In the subgroup analyses, NAFLD was associated with a lower risk of incident BMD decrease in females even after adjustment for confounders. The direction of the effect of NAFLD on the risk of BMD decrease changed depending on BMI category and body fat percentage, although the impact was statistically insignificant. Conclusions: NAFLD had a significant protective effect on BMD in females. However, the effects may vary depending on BMI category or body fat percentage.

Regression analysis of doubly censored failure time data with frailty time data with frailty

  • Kim Yang-Jin
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2004년도 학술발표논문집
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    • pp.243-248
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    • 2004
  • The timings of two successive events of interest may not be measurable, instead it may be right censored or interval censored; this data structure is called doubly censored data. In the study of HIV, two such events are the infection with HIV and the onset of AIDS. These data have been analyzed by authors under the assumption that infection time and induction time are independent. This paper investigates the regression problem when two events arc modeled to allow the presence of a possible relation between two events as well as a subject-specific effect. We derive the estimation procedure based on Goetghebeur and Ryan's (2000) piecewise exponential model and Gauss-Hermite integration is applied in the EM algorithm. Simulation studies are performed to investigate the small-sample properties and the method is applied to a set of doubly censored data from an AIDS cohort study.

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Association Between Green Tea Consumption and Lung Cancer Risk

  • Lee, Andy H.;Liang, Wenbin;Hirayama, Fumi;Binns, Colin W.
    • Journal of Preventive Medicine and Public Health
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    • 제43권4호
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    • pp.366-367
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    • 2010
  • Green tea is a popular beverage and its health benefits are well known. However, inconsistent results have been reported in observational studies concerning the association between green tea consumption and the lung cancer risk. In this commentary, several methodological issues underlying the measurement of tea exposure are highlighted. The recommendations should be useful for designing and planning prospective cohort studies to ascertain the protective effect of green tea against lung cancer.