보건ㆍ의학 통계의 이해

강대룡 대한인터벤션영상기술학회 2005 대한인터벤션영상기술학회지 Vol.8 No.1

Impact of Serum Leptin to Adiponectin Ratio on Regression of Metabolic Syndrome in High-Risk Individuals: The ARIRANG Study

강대룡,안성복,Dhananjay Yadav,고상백,김장영 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.2

Purpose: The ratio of serum leptin to adiponectin (L/A ratio) could be used as a marker for insulin resistance. However, few prospectivestudies have investigated the impact of L/A ratio on improvement of metabolic components in high-risk individuals with metabolic syndrome. We examined the association between L/A ratio and the regression of metabolic syndrome in a population-based longitudinal study. Materials and Methods: A total of 1017 subjects (431 men and 586 women) with metabolic syndrome at baseline (2005–2008) were examined and followed (2008–2011). Baseline serum levels of leptin and adiponectin were analyzed by radioimmunoassay. Area under the receiver operating characteristics curve (AUROC) analyses were used to assess the predictive ability of L/A ratio for the regression of metabolic syndrome. Results: During an average of 2.8 years of follow-up, metabolic syndrome disappeared in 142 men (32.9%) and 196 women (33.4%). After multivariable adjustment, the odds ratios (95% confidence interval) for regression of metabolic syndrome in comparisonsof the lowest to the highest tertiles of L/A ratio were 1.84 (1.02–3.31) in men and 2.32 (1.37–3.91) in women. In AUROC analyses, L/A ratio had a greater predictive power than serum adiponectin for the regression of metabolic syndrome in both men (p=0.024) and women (p=0.019). Conclusion: Low L/A ratio is a predictor for the regression of metabolic syndrome. The L/A ratio could be a useful clinical marker for management of high-risk individuals with metabolic syndrome.

Dr. Chang Sei Kim: A Public Health Pioneer Devoted to Korea’s Independence Movement

강대룡,서일,최재건 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.5

초등학교 체육과 열린수업의 실제

강대룡 晋州敎育大學校 初等敎育硏究所 1999 初等敎育硏究 Vol.9 No.-

환자-대조군 연구에서 인구집단 층화가 일배체형 경향성 검정에 미치는 영향

김진흠,강대룡,임현선,남정모,Kim, Jin-Heum,Kang, Dae-Ryong,Lim, Hyun-Sun,Nam, Chung-Mo 한국통계학회 2009 응용통계연구 Vol.22 No.5

Population stratification can cause spurious associations between genetic markers and disease locus. In order to handle this population stratification in haplotype-based case-control association studies, we added population indicators as covariates to the haplotype trend regression model proposed by Zaykin et al. (2002). We investigated through simulations how both population stratification and measurement error in the estimation of true population of each individual affect type I error probabilities of the association tests based on both Zaykin et al.'s (2002) model and the proposed model. Based on those results, in the situation that there exists population stratification but there is no error in population classification of each individual, our proposed model does satisfy a type I error probability whereas Zaykin et al.'s (2002) model does not. However, as the measurement error increases, a type I error probability of our model correspondingly becomes larger than a nominal significance level. It implies that as long as uncertainty in the estimation of true population of each individual still remains, it is nearly impossible to avoid false positive in case-control association studies based on haplotypes. 환자-대조군 연관성 연구에서 후보 유전자와 질병이 연관되어 있지 않더라도 인구집단 층화로 인해 가짜 연관성이 발생할 수도 있다. 본 연구에서는 일배체형에 기초한 환자-대조군 연관성 연구에서 인구집단 층화로 인한 가짜 연관성을 해결하기 위한 방법으로, Zaykin 등 (2002)이 제안한 일배체형 경향성 모형에 인구집단 층화에 대한 정보를 추가하고자 한다. Zaykin 등 (2002)의 모형과 제안한 모형에 기초한 일배체형의 유의성 검정에서 인구집단 층화와 인구집단에 대한 관측 오차가 제1종 오류율에 미치는 영향을 모의실험을 통해 살펴보았다. 인구집단이 층화되어 있지만 각 개체가 속한 인구집단을 정확히 알 수 있을 때, Zaykin 등 (2002)의 모형에 기초한 검정은 제1종 오류율을 잘 조절하지 못했지만 본 연구에서 제안한 모형에 기초한 검정은 제1종 오류율을 잘 조절하는 것으로 나타났다. 그러나 인구집단이 층화되어 있고 관측 오차가 존재하면 제안한 모형에 기초한 검정도 제1종 오류율을 조절하지 못하고 명목 유의수준보다 큰 값을 갖는 것으로 나타났다. 따라서 단일염기다형성에 기초한 환자-대조군 연관성 연구와 마찬가지로 일배체형에 기초한 환자-대조군 연관성 연구에서도 인구집단 층화에 대한 정보를 갖고 있다할지라도 그 속에 관측 오차가 존재하면 위양성을 피하기 어렵다는 것을 알 수 있었다.

상부위장관 : 내시경 또는 내시경 초음파를 이용한 위암 심달도 판정의 정확도 비교

송경호,강대룡,이상길,천재희,김지현,정재복,이용찬 대한소화기학회 2007 대한소화기학회 추계학술대회 Vol.2007 No.-

유방암 조기진단을 위한 검진주기 결정에 대한 연구

정성화,강대룡,허남욱,김진흠,이순영,정상혁,남정모,Jeong, Seong-Hwa,Kang, Dae-Ryong,Hur, Nam-Wook,Kim, Jin-Heum,Lee, Soon-Young,Jung, Sang-Hyuk,Nam, Chung-Mo 대한예방의학회 2006 예방의학회지 Vol.39 No.4

Objectives: The purposes of this study were to propose a screening schedule for the early detection of breast cancer among Korean women, as based on the statistical model, and to compare the efficacy of the proposed screening schedule with the current recommendations. Methods: The development of the screening schedule for breast cancer closely followed the work of Lee and Zelen (1998). We calculated the age-specific breast cancer incidence rate from the Korea Central Cancer Registry (2003), and then we estimated the scheduling of periodic examinations for the early detection of breast cancer, using mammography, and based on the threshold method. The efficacy of the derived screening schedule was evaluated by the schedule sensitivity. Results: For estimating the screening schedule threshold method, we set the threshold value as the probability of being in the preclinical stage at age 35, the sensitivity of mammography as 0.9 and the mean sojourn time in the preclinical stage as 4 years. This method generated 14 examinations within the age interval [40, 69] of 40.0, 41.3, 42.7, 44.1, 45.4, 46.7, 48.0, 49.3, 51.0, 53.2, 55.3, 57.1, 59.0 and 63.6 years, and the schedule sensitivity was 75.4%. The proposed screening schedule detected 85.2% (74.5/87.4) of the cases that could have been detected by annual screening, but it required only about 48.7% (14.0/30.0) of the total number of examinations. We also examined the threshold screening schedules for a range of sensitivities of mammography and the mean sojourn time in the preclinical stage. Conclusions: The proposed screening schedule for breast cancer with using the threshold method will be helpful to provide guidelines for a public health program for choosing an effective screening schedule for breast cancer among Korean women.

모유수유 실천 및 수유기간에 영향을 미치는 요인

황원주,강대룡,서문희,정우진,Hwang, Won-Ju,Kang, Dae-Ryong,Suh, Moon-Hee,Chung, Woo-Jin 대한예방의학회 2006 예방의학회지 Vol.39 No.1

Objectives: The purpose of this study is to examine the factors affecting the rate and duration of breastfeeding. Methods: We analyzed the data from the year 2000 Korea National Fertility Survey that was collected through direct interviews. In particular, the mothers who delivered their last child and the child was under 1 year of age from January 1998 to June 2000 (N=1,066) were analyzed via a logistic model to assess the factors affecting the breastfeeding rate. Among the study subjects, those who had initiated breastfeeding (N=740) were analyzed through Cox's proportional hazard model to evaluate the factors affecting the duration of breastfeeding. Results: The multivariate logistic model showed that the delivery type and the baby's birth-weight have a statistically significant influence on the breastfeeding rate. Women who delivered their babies through Cesarean section were less likely than others to breastfeed. In contrast, the women whose babies weighed 2.5Kg or more were more likely than others to breastfeed. The results obtained from the survival analysis are as follows: the higher the mother's education level, the shorter is the breastfeeding duration. The mother's work status played a significant role in the early termination of breastfeeding. Women aged 35 or older showed a longer breastfeeding duration than the younger age groups, whereas the maternal age was not a significant factor in affecting whether or not a mother would breastfeed. Conclusions: Reducing the cases of operative delivery (Cesarean section) and low weight births, enlightening young and highly educated women on breastfeeding and improving the environment for breastfeeding on the job are important strategies to encourage women to breastfeed.

일배체형에 기초한 연쇄분석의 통계학적 알고리즘 연구

김진흠,강대룡,이윤경,신선미,서일,남정모,Kim, Jin-Heum,Kang, Dae-Ryong,Lee, Yun-Kyung,Shin, Sun-Mi,Suh, Il,Nam, Chung-Mo 대한예방의학회 2004 예방의학회지 Vol.37 No.4

Objectives : This study was conducted to propose a new transmission/disequilibrium test(TDT) to test the linkage between genetic markers and disease-susceptibility genes based on haplotypes. Simulation studies were performed to compare the proposed method with that of Zhao et al. in terms of type I error probability and powers. Methods : We estimated the haplotype frequencies using the expectation-maximization(EM) algorithm with parents genotypes taken from a trio dataset, and then constructed a two-way contingency table containing estimated frequencies to all possible pairs of parents haplotypes. We proposed a score test based on differences between column marginals and their corresponding row marginals. The test also involved a covariance structure of marginal differences and their variances. In simulation, we considered a coalescent model with three genetic markers of biallele to investigate the performance of the proposed test under six different configurations. Results : The haplotype-based TDT statistics, our test and Zhao et al.'s test satisfied a type I error probability, but the TDT test based on single locus showed a conservative trend. As expected, the tests based on haplotypes also had better powers than those based on single locus. Our test and that of Zhao et al. were comparable in powers. Conclusion : We proposed a TDT statistic based on haplotypes and showed through simulations that our test was more powerful than the single locus-based test. We will extend our method to multiplex data with affected and/or unaffected sibling(s) or simplex data having only one parent s genotype.

우리나라 노인여성의 골다공증성 척추골절로 인한 경제적 부담 추계

강혜영,강대룡,장영화,박성은,최원정,문성환,양규현,Kang, Hye-Young,Kang, Dae-Ryong,Jang, Young-Hwa,Park, Sung-Eun,Choi, Won-Jung,Moon, Seong-Hwan,Yang, Kyu-Hyun 대한예방의학회 2008 예방의학회지 Vol.41 No.5

Objectives : To estimate the economic burden of osteoporotic vertebral fracture (VF) from a societal perspective. Methods : From 2002 to 2004, we identified all National Health Insurance claims records for women ${\geq}50$ years old with a diagnosis of VF. The first 6-months was defined as a "clearance period," such that patients were considered as incident cases if their first claim of fracture was recorded after June 30, 2002. We only included patients with ${\geq}$ one claim of a diagnosis of, or prescription for, osteoporosis over 3 years. For each patient, we cumulated the claims amount for the first visit and for the follow-up treatments for 1 year. The hospital charge data from 4 hospitals were investigated to measure the proportion of the non-covered services. Face-to-face interviews were conducted with 106 patients from the 4 study sites to measure the out-of-pocket spending outside of hospitals. Results : During 2.5 years, 131,453 VF patients were identified. The patients had an average of 3.38 visits, 0.40 admissions and 6.36 inpatient days. The per capita cost was 1,909,690 Won: 71.5% for direct medical costs, 20.6% for direct non-medical costs and 7.9% for indirect costs. The per capita cost increased with increasing age: 1,848,078 Won for those aged 50-64, 2,084,846 Won for 65-74, 2,129,530 Won for 75-84and 2,121,492 Won for those above 84. Conclusions : Exploring the economic burden of osteoporotic VF is expected to motivate to adopt effective treatment options for osteoporosis in order to prevent the incidence of fracture and the consequent costs.