• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.402-408
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• 2016

Background: Ascertainment bias are common in epidemiologic studies to assess the association between thyroid cancer risk and living near nuclear power plants because many thyroid cancers are diagnosed by chance through health examination. We surveyed the ultra sonography (USG) examination history and conducted thyroid and breast USG in residents living near nuclear power plants. Materials and Methods: The study population comprised 2,421 residents living near nuclear power plants in Korea. Information on demographic characteristics, including diagnostic examination history, was collected by interview using questionnaires. USG examination was conducted to evaluate the presence of thyroid nodules and breast lesion. Study participants were divided into 3 groups according to the distance of their respective villages from a nuclear power plant. The proportions of USG examination history and prevalence of thyroid nodules and breast lesions were compared between groups. Results and Discussion: Examination histories of thyroid USG were 23.1%, 13.7%, and 10.5% in men and 31.3%, 26.7%, 18.3% in women in the short, intermediate, and long distance groups, respectively. There were significant inverse associations between thyroid USG history and the distance from nuclear power plants (P for trend = 0.001 for men and 0.017 for women). However, there was no association between the distance of villages from nuclear power plants and prevalence of thyroid nodules. Conclusion: Our results suggest that there may be an ascertainment bias in population-based studies examining the harmful effects of NPPs examination and researchers should pay attention to ascertainment bias resulted from differential health examination. Correction for ascertainment bias, active follow-up and examination for all study population to remove differential health examination is needed.

• Communications for Statistical Applications and Methods
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• 제26권2호
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• pp.103-129
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• 2019

The main goal of a case-control study is to learn the association between various risk factors and a primary outcome (e.g., disease status). Particularly recently, it is also quite common to perform secondary analyses of the case-control data in order to understand certain associations between the risk factors of the primary outcome. It has been repeatedly documented with case-control data, association studies of the risk factors that ignore the case-control sampling scheme can produce highly biased estimates of the population effects. In this article, we review the issues of the naive secondary analyses that do not account for the biased sampling scheme, and also the various methods that have been proposed to account for the case-control ascertainment. We additionally compare the results of many of the discussed methods in an example examining the association of a particular genetic variant with smoking behavior, where the data were obtained from a lung cancer case-control study.

• 한국과 국제사회
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• 제1권2호
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• pp.5-32
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• 2017

5.18 광주 민중항쟁은 1993년 5월 김영삼 대통령에 의해 합법적인 민주화운동으로 인정받았고, 2011년 유네스코는 '5.18 광주민주항쟁'을 세계기록 유산으로 승인하였다. 이는 광주시민의 명예 회복에 전기를 마련하는 일이었다. 하지만 사건 발생 37년이 지난 지금도 이에 대한 평가는 전국적으로 통일되지 않았고, 어쩌면 광주만의 정신, 광주만의 자부심으로 기억되고 있는지 모르겠다. 이러한 상황이 지속되는 여러 요인들이 있겠지만, 본 연구자는 5.18의 진상규명과 시대정신에 맞는 재해석, 시민교육을 담당할 전문가들이 전라도와 서울에 집중적으로 분포되어 있다는 점이 가장 큰 요인으로 작용하고 있다고 생각한다. 게다가 5.18을 달리 평가하는 저널이 가해자 지역에 적을 두고 활동하고 있어 평가가 양분 된 채 통일되지 못하고 호남에 갇혀있게 된 것이라 생각한다. 본 연구는 5.18의 의미가 전국적으로 통일되지 못하고 호남에 갇혀있게 된 요인으로 5.18관련자들만의 "당사자주의"의 한계에 있다 판단하고 있다. 특히 이 사건을 객관적인 시각으로 분석하고 해명해야 할 연구자들이 연고지역에 편중분포(광주 전라도>서울>경남)되어 있어 5.18의 의미가 통일되지 못하고 있는 것이 아닌지 그 개연성에 주목하게 되었다. 이 연구에서는 학술연구논문과 저널 저자 및 출판 소재지가 양분되어 있고, 편중분포 되어 있음을 밝히고, 연구자들의 편중분포가 지역성 극복에 걸림돌이 되고 있다는 개연성을 밝히고자 한다.