Statistics in clinical Trials : Meta Analysis in Clinical Trials

남정모 ( Chung Mo Nam ) 한국보건정보통계학회 2007 보건정보통계학회 추계학술대회 Vol.2007 No.-

건강관련이론 : 연구방법 ; 시계열 자료의 분석 : 시계열 개입분석

남정모(Chung Mo Nam) 연세대학교 김모임간호학연구소 1995 간호학탐구 Vol.4 No.1

N/A

초경시기와 아동기 및 청소년기의 신체성장의 변화 : 강화연구

김창수,남정모,김덕희,김현창,이강희,지선하,서일,Kim, Chang-Soo,Nam, Chung-Mo,Kim, Duck-Hi,Kim, Hyun-Chang,Lee, Kang-Hee,Jee, Sun-Ha,Suh, Il 대한예방의학회 2000 예방의학회지 Vol.33 No.4

Objectives : To assess height, weight and body mass index from childhood to adolescence according to the age at menarche and hence to study the influence of childhood growth on the menarche age. Methods : $\lceil$The Kangwha Study$\rfloor$was a community-based prospective cohort study which included the entire population of 219 female first graders in Kangwha county in 1986. Among the 219 girls, 119 girls who had received complete follow up checks during the study period$(1986\sim1997)$, were included in this study, except one for whom menarche age information was unavailable. The remaining 118 girls were divided into three groups according to the timing of menarche : early(<25 percentile), intermediate and late($\geq75$ percentile) maturers. Results : The average age at menarche was 12.7 years . early 11.3 years, intermediate 12.6 years and late 13.7 years. The early maturers were taller and heavier between $6\sim8$ years. But, the mean weight and body mass index at the menarche age did not differ statistically among the three groups. The weight and body mass index of the early maturers were consistently higher than those of the late maturers over the entire period of the study. Conclusions : Critical body weight and body mass index must be attained for menstruation to be attained and the age at menarche is largely determined by the childhood growth. In addition, it seems that childhood growth and age at menarche are associated with adolescent weight and body mass index.

이중구간중도절단된 생존자료의 생존함수 비교를 위한 검정: 한국인 암 예방연구 중 당뇨병에의 응용

지선하,남정모,김진흠,Jee, Sun-Ha,Nam, Chung-Mo,Kim, Jin-Heum 한국통계학회 2009 응용통계연구 Vol.22 No.3

이중구간중도절단된 자료의 생존함수를 비교하기 위한 두 검정법을 소개하고 한국인 암 예방연구 (Jee 등, 2005) 자료에 적용하여 당뇨병 잠복시간의 분포를 성별과 연령에 따라 비교하였다. Kim 등 (2006)의 검정법을 이중구간중도절단된 자료로 확장한 검정법은 위험집합의 크기에만 의존하는 가중값을 사용하기 때문에 대용량 자료의 분석에서 Sun (2006)의 검정법보다 계산 시간을 대폭 줄일 수 있으며, 이산형 생존자료뿐만 아니라 연속형 생존자료에도 적용가능한 장점이 있다. 당뇨병의 잠복시간이 성별에 따라 매우 유의하게 달랐으며 여자의 잠복시간이 남자보다 긴 것으로 나타났다. 4개 연령그룹 간 당뇨병의 잠복시간도 성별에 관계 없이 매우 유의하게 달랐으며 여자의 경우가 남자의 경우보다 그 차이가 훨씬 더 유의했다. 한편, 소표본 모의실험을 통해 제안한 검정법과 Sun (2006)의 검정법의 검정력을 비교하였으며 제안한 검정법의 검정력이 Sun (2006)의 검정법보다 더 좋은 것으로 나타났다. Two tests were introduced for comparing several survival functions with doubly interval-censored data and illustrated with data surveyed by Korean Cancer Prevention Study (Jee et al., 2005). The test which extended Kim et al. (2006)'s test to the doubly interval-censored data has an advantage over Sun (2006)'s test in terms of saving computation time because the proposed test only depends on the size of risk set, and also the proposed test is applicable to continuous failure time data as well as discrete failure time data unlike Sun's test. Comparing male with female groups on the incubation time of diabetes was highly different and the survival of female group was longer than that of male one. Regardless of gender, the difference in survival functions of four age groups was highly significant with p-value of less than 0.001. This trend was more remarkable for female group than for male one. Simulation results showed that the significance level of both tests was well controlled and the proposed test was better than Sun's test in terms of power.

일배체형에 기초한 고혈압과 ACE 유전자의 연관성 분석

김진흠,남정모,강대룡,서일,Kim Jinheum,Nam Chung Mo,Kang Dae Ryong,Suh Il 한국통계학회 2005 응용통계연구 Vol.18 No.2

In this study we investigate the association between the haplotype block of 4 SNPs in ACE genes and hypertension with a case-control dataset of size of 277 and 40 families data collected from Kangwha studies. To this end we perform a haplotype-based case-control association study and a haplotype-based TDT study. We do the same analysis with tag-SNPs that can identify the haplotype block. Through a cladogram analysis we make the evolution-tree of haplotypes and then classify the haplotypes into a few clades by collecting haplotypes exposed to the disease to the same extent. We also discuss the association between these clades and hypertension. 본 연구에서는 강화연구(서일, 2004)를 통해 수집된 277명의 환자-대조군 자료와 40개의 가계 자료를 이용하여 ACE(angiotensin-I converting enzyme) 유전자 내에 있는 4개의 단일염기다형성(single nucleotide polymorphism; SNP)으로 이루어진 일배체형(haplotype)과 고혈압의 관련성을 알아보고자 한다. 이를 위해 일배체형에 기초한 환자-대조군의 우도비 검정과 가계 자료의 TDT(transmission/disequilibrium test) 연구를 수행하고자 한다. 또한 이 일배체형을 동정(identification)할 수 있는 tag-SNPs에 기초하여 동일한 연구를 하고자 하며, Seltman 등(2003)이 제안한 분기도(cladogram) 분석 방법을 써서 일배체형의 진화 과정에서 가깝게 위치하고 질병 발생 위험이 비슷한 클레이드(clade)를 찾아내고 이 클레이드와 고혈압의 연관성을 살펴보고자 한다.

혈압의 역학적 연구와 지속성(tracking)에 대한 통계학적 분석

서일,남정모,강형곤,Suh, Il,Nam, Chung-Mo,Kang, Hyung-Gon 한국통계학회 1993 응용통계연구 Vol.6 No.2

이 연구는 혈압에 대한 역학적인 연구의 특성 및 중요성을 소개하고 우리나라 아동의 혈압에 지속성 현상이 있는가를 밝히고자 하였다. 지속송에 대한 통계적 분석방법으로서 상관분석, 성장곡선 모형을 이용한 McMahan의 방법, 그리고 Blomqvist가 제안한 방법등을 우리나라 일부지역에서 6년간 추적관찰된 아동혈압자료에 적용하여 그 결과들을 비교 분석하였다. 측정오차를 교정한 상관분석은 계산이 용이하다는 장점이 있으나 추정된 상관계수 행렬이 시간의 차(lag-difference)에 따라 단조함수가 되지 않을 수 있으며 이런 경우 지속성에 대한 해석상의 어려움이 있다. McMahan 모형은 지속성을 역학적인 관점에서 타당성이 이다고 생각되는 상대 순위의 유지도란 개념으로 정의하고 또한 전체자료에 대한 공분산구조를 모형에 반영하여 요약된 지속성에 대한 지표를 계산할 수 있는 장점이 있으나, 계산이 복잡하고 성장곡선모수의 치수를 결정하는데 따른 어려움이 있다. Blomqvist 모형은 지속성을 초기 시점에서의 측정값과 전체 시계열자료에서의 변화율간의 선형적인 관계로부터 정의하고 이 경우 발생할 수 있는 평균으로서의 회귀에 대한 영향을 수학적으로 교정하였다는 장점이 있으나, 추정값이 양수가 아닌 경우 역학적인 관점에서의 해석상의 문제점이 존재한다. This study introduced speical characteristics of an epidemiologic study on blood pressure and compared several statistical methods for evaluating the tracking phenomenon of blood pressure for Korean children. While correlation coefficients adjusted for measurement error are commonly used for the evaluation of tracking, it is hard to interpretate the results when correlation functions for lag-difference are not monotonous. McMahan defined a tracking as maintenance of relative rank over time and calculated tracking index usng growth curve model. The tracking index in McMahan's model is complicate to calculate, and it is hard to determine the degree of growth curve parameter. Blomqvist showed the relationship between the rate of change and the initial value. This concept could be extended for the evaluation of tracking. However, it is not so easy to interpretate the estimates in his model when those are non-positive.

과천시민의 고혈압 인지, 치료, 조절과의 관련요인

최연희,남정모,주미현,문기태,심지선,김현창,서일,Choi, Youn-Hee,Nam, Chung-Mo,Joo, Mi-Hyun,Moon, Ki-Tae,Shim, Jee-Seon,Kim, Hyeon-Chang,Suh, Il 대한예방의학회 2003 예방의학회지 Vol.36 No.3

Objectives : To identify the factors related to awareness, treatment, and control of hypertension in a Gwacheen population. Methods : This study surveyed 1,176 Gwacheon residents older than 40 years, and measured blood pressure using a standardized guideline in 1999. The study subjects were 473 adults (175 males, 295 females) with hypertension defined as a systolic blood pressure $\geq$140 mmHg, diastolic blood pressure $\geq$90 mmHg or reported treatment with antihypertensive medication. Information on awareness, treatment, and control of hypertension, and sociodemographic and health-related factors .was collected through person-to-person interviews with a structured questionnaire. Results : Overall, 252 (53.3%) of hypertensive subjects were aware of their condition, of whom as many as 193 (76.6%) were being treated, and 81 (42.0%) had their blood pressure controlled at the recommended level (<140/90 mmHg). However, of the 473 subjects found to have hypertension, only 40.8% were being treated, and 17.1% were under control. There were no significant differences in the proportions of awareness, treatment, and control of hypertension. In multiple logistic regression models, awareness of hypertension was positively associated with age and family history of hypertension in females. Control of hypertension was also positively associated with haying a partner and marital status in females.. Conclusion : These findings demonstrate that much greater efforts on improving awareness, treatment, and control of hypertension are needed, even in urban community settings, considering related factors such as a9e, family history, and marital status. However, these factors should be further investigated for their causal relationship.

농약사용과 사망률과의 관계에 대한 코호트연구

오희철,남정모,이선희,Oh, Hee-Chul,Nam, Chung-Mo,Lee, Sun-Hee 대한예방의학회 1991 예방의학회지 Vol.24 No.3

The purpose of this study is to examine the relationship between pesticide use and mortality, and cancer mortality which are recognized as health hazards of pesticides. Data were analyzed from a cohort of 6,066 people aged fifty-five or over and who have been residing in the main island of Kangwha county. Death certificates, computerized citizenship registers searches, and household interview survey lead to get more than ninety-seven percents follow-up rate for the first five year observation period. Important findings are as follows : 1. Age specific mortality rates of pesticide users are significantly lower than those of pesticides nonusers. The SMR of male is 0.80, and 0.58 for females respectively probably due to healthy worker effects. But, age specific cancer mortality rates are significantly higher than those of pesticide nonusers (SMR=1.59) in males. This finding is not observed in females (SMR=0.85), however. 2. Logistic regression analyses showed that self-reported health status, drinking, and smoking histories in male are significantly associated with total mortality rate. The histories of pesticide use are also calculated to be highly associated with cancer mortality as in univariate analyses in males. In female, self-reported health status, age of first delivery are found to be significantly related to total mortality rate. Only drinking history is calculated to be associated with cancer mortalities in females. Data from further observation of 'Kangwha cohort' and indepth analyses of these are highly expected.

성장기 청소년의 혈압변화와 결정요인

서일,남정모,지선하,김석일,김영옥,김성순,심원흠,김춘배,이강희,하종원,강형곤,오경원,Suh, Il,Nam, Chung-Mo,Jee, Sun-Ha,Kim, Suk-Il,Kim, Young-Ok,Kim, Sung-Soon,Shim, Won-Heum,Kim, Chun-Bae,Lee, Kang-Hee,Ha, Jong-Won,Kang, Hyung-Gon,Oh, Ky 대한예방의학회 1997 예방의학회지 Vol.30 No.2

본 연구는 1992년 당시 경기도 강화군 강화읍내에 거주하는 중학교 1학년에 재학중인 남자 335명과 여자 375명을 대상으로 5년간 혈압수준 및 변화에 대한 분포를 제시하고 혈압수준 및 변화의 결정 요인을 밝히고자 하였다. 혈압의 수준 및 변화와 관련된 요인으로는 신체적 요인, 혈청학적 요인 및 영양소 섭취요인을 조사하였다. 주요 연구결과는 다음과 같다. 1. 12세부터 16세까지 5년간 남자의 수축기혈압의 평균은 108.7mmHg에서 118.1mmHg로, 이완기혈압의 평균은 69.5mmHg에서 73.4mmHg로 증가하였으며 15세에 가장 높은 혈압수준을 보였다. 그러나 동기간 동안 여자의 수축기혈압의 평균은 114.4mmHg에서 113.5mmHg로, 이완기혈압의 평균은 75.2mmHg에서 72.1mmHg로 감소하였으며 13-14세 때에 가장 높은 혈압 수준을 보였다. 2. 남자의 5년간 신장, 체중, 신체비만지수 등은 계속 성장하였으나 여자는 15세를 기점으로 신체적 성장이 둔화되는 경향을 보였다. 한편 연령이 증가할 수록 남자의 혈청 총 콜레스테롤은 감소하고 중성지방은 증가하는 경향을 보였으나 여자에서는 특별한 변화가 없었다. 식이섭취에서는 지질의 섭취가 연령에 따라 약간 증가하는 경향을 보였으나 전반적으로 남녀 모두 에너지의 20% 정도였다. 3. 혈압수준과 체중, 신체비만지수, 피부두께 등은 남녀 모두 각 연령에서 통계학적으로 유의한 관련성이 있었다. 신체비만지수의 영향을 통제하였을 때 혈청 총 콜레스테롤은 남자에서 연령의 증가에 따라 수축기혈압과 음의 관계에서 양의 관계로, 여자의 경우에는 이완기혈압과 15-16세에서 양의 관련성을 보였다. 그리고 중성지방과 크레아티닌은 남자에서는 혈압과 양의 관련성을 보였으나 여자의 경우에는 관련성이 없었다. 한편 영양소 섭취와 혈압과의 관계는 성별-연령별로 일관성 있는 결과가 없었으나 남자의 이완기혈압과 단백질 섭취가 양의 관련성이 있었고 여자의 14세 때 수축기혈압과 비타민 A 섭취가 음의 관련성이 있었다. 4. 혈압변화와 신체비만지수의 변화, 혈청 총 콜레스테롤의 변화는 남녀 모두 양의 관련성을 보였으며 크레아티닌의 변화는 남자에서는 양의 관계를, 여자에서는 음의 관계를 보였다. 또한 남자에서 소디움 섭취가 높은 군이 계속해서 높은 혈압수준을 유지하였으며 여자의 경우에는 에너지에 대한 지질 섭취비율이 높은 군이 계속해서 낮은 혈압수준을 유지하여 성별에 따른 차이를 보였다. 전체적으로 성장기 혈압변화에 가장 큰 영향을 미치는 요인은 남녀 모두 신체비만 지수이었다. Many studies have led to the notion that essential hypertension in adults is the result of a process that starts early in life: investigation of blood pressure(BP) in children and adolescents can therefore contribute to knowledge of the etiology of the condition. A unique longitudinal study on BP in Korea, known as Kangwha Children's Blood Pressure(KCBP) Study was initiated in 1986 to investigate changes in BP in children. This study is a part of the KCBP study. The purposes of this study are to show changes in BP and to determine factors affecting to BP level and change in Korean adolescents during age period 12 to 16 years. A total of 710 students(335 males, 375 females) who were in the first grade at junior high school(12 years old) in 1992 in Kangwha County, Korea have been followed to measure BP and related factors(anthropometric, serologic and dietary factors) annually up to 1996. A total of 562 students(242 males, 320 females) completed all five annual examinations. The main results are as follows: 1. For males, mean systolic and diastolic BP at age 12 and 16 years old were 108.7 mmHg and 118.1 mmHg(systolic), and 69.5 mmHg and 73.4 mmHg(diastolic), respectively. BP level was the highest when students were at 15 years old. For females, mean systolic and diastolic BP at age 12 and 16 years were 114.4 mmHg and 113.5 mmHg(systolic) and 75.2 mmHg and 72.1 mmHg(diastolic), respectively. BP level reached the highest point when they were 13-14 years old. 2. Anthropometric variables(height, weight and body mass index, etc) increased constantly during the study period for males. However, the rate of increase was decreased for females after age 15 years. Serum total cholesterol decreased and triglyceride increased according to age for males, but they did not show any significant trend fer females. Total fat intake increased at age 16 years compared with that at age 14 years. Compositions of carbohydrate, protein and fat among total energy intake were 66.2:12.0:19.4, 64.1:12.1:21.8 at age 14 and 16 years, respectively. 3. Most of anthropometric measures, especially, height, body mass index(BMI) and triceps skinfold thickness showed a significant correlation with BP level in both sexes. When BMI was adjusted, serum total cholesterol showed a significant negative correlation with systolic BP at age 12 years in males, but at age 14 years the direction of correlation changed to positive. In females serum total cholesterol was negatively correlated with diastolic BP at age 15 and 16 years. Triglyceride and creatinine showed positive correlation with systolic and diastolic BP in males, but they did not show any correlation in females. There was no consistent findings between nutrient intake and BP level. However, protein intake correlated positively with diastolic BP level in males. 4. Blood pressure change was positively associated with changes in BMI and serum total cholesterol in both sexes. Change in creatinine was associated with BP change positively in males and negatively in females. Students whose sodium intake was high showed higher systolic and diastolic BP in males, and students whose total fat intake was high maintained lower level of BP in females. The major determinants on BP change was BMI in both sexes.

DRG 도입이 메디케어 의료비 증가억제에 미친 효과

김한중,남정모,Kim, Han-Joong,Nam, Chung-Mo 대한예방의학회 1994 예방의학회지 Vol.27 No.1

The United States adopted DRG based prospective payment system (PPS) in order to control the inflation of health care costs. No study used statistical test while many studies reported the cost containing effect of the PPS. To study impacts of the PPS on the Medicare expenditure, this study set the following three hypotheses (1) The PPS decelerated the increase in the hospital expenditure (Part A), (2) the PPS accelerated the increase in the expenditure of outpatients and physicians (Part B), (3) the increase in total expenditure was decelerated inspite of the spill over (substitution) effect because saving in the Part A expenditure were greater than losses in the Part B expenditure. The dependent variables are per capita hospital expenditure, per capita Part B expenditure, and per capita total expenditure for the Medicare beneficiaries. An intervention analysis, which added intervention effect to the time series variation on the Box-Jenkins model, was used. The observations included 120 months from 1978 to 1987. The results are as follows : (1) The annual increase in the per capita Part A expenditure was $5.11 after the implementation of DRG where as that before the PPS had been $11.1. The effect of the reduction ($5.99) was statistically significient (t=-3.9). (2) The spill over (substitution) effect existed because the annual increase in the per capita Part B expenditure was accelerated by $1.73 (t=1.91) after the implementation of the PPS. (3) The increase in the total Medicare expenditure per capita was reduced by $4.26 (t=-2.19) because the spill over effect was less than cost savings in the Part A expenditure.