퇴행성 관절염 환자를 대상으로 새로운 진통제 평가를 위한 임상시험자료의 GEE 분석

임회정,김윤이,정영복,성상철,안진환,노권재,김정만,박병주,Lim, Hoi-Jeong,Kim, Yoon-I,Jung, Young-Bok,Seong, Sang-Cheol,Ahn, Jin-Hwan,Roh, Kwon-Jae,Kim, Jung-Man,Park, Byung-Joo 대한예방의학회 2004 예방의학회지 Vol.37 No.4

Objective : To compare the efficacy between SKI306X and Diclofenac by using generalized estimating equations (GEE) methodology in the analysis of correlated bivariate binary outcome data in Osteoarthritis (OA) diseases. Methods : A randomized, double-blind, active comparator-controlled, non-inferiority clinical trial was conducted at 5 institutions in Korea with the random assignment of 248 patients aged 35 to 75 years old with OA of the knee and clinical evidence of OA. Patients were enrolled in this study if they had at least moderate pain in the affected knee joint and a score larger than 35mm as assessed by VAS (Visual Analog Scale). The main exposure variable was treatment (SKI 306X vs. Diclofenac) and other covariates were age, sex, BMI, baseline VAS, center, operation history (Yes/No), NSAIDS (Y/N), acupuncture (Y/N), herbal medicine (Y/N), past history of musculoskeletal disease (Y/N), and previous therapy related with OA (Y/N). The main study outcome was the change of VAS pain scores from baseline to the 2nd and 4th weeks after treatment. Pain scores were obtained as baseline, 2nd and 4th weeks after treatment. We applied GEE approach with empirical covariance matrix and independent(or exchangeable) working correlation matrix to evaluate the relation of several risk factors to the change of VAS pain scores with correlated binary bivariate outcomes. Results : While baseline VAS, age, and acupuncture variables had protective effects for reducing the OA pain, its treatment (Joins/Diclofenac) was not statistically significant through GEE methodology (ITT:aOR=1.37, 95% CI=(0.8200, 2.26), PP:aOR=1.47, 95% CI=(0.73, 2.95)). The goodness-of-fit statistic for GEE (6.55, p=0.68) was computed to assess the adequacy of the fitted final model. Conclusions : Both ANCOVA and GEE methods yielded non statistical significance in the evaluation of non-inferiority of the efficacy between SKI306X and Diclofenac. While VAS outcome for each visit was applied in GEE, only VAS outcome for the fourth visit was applied in ANCOVA. So the GEE methodology is more accurate for the analysis of correlated outcomes.

노인인구에서 음주와 대장직장암 발생간의 연관성에 관한 코호트연구

임회정,박병주,Lim, Hoi-Jeong,Park, Byung-Joo 대한예방의학회 2008 예방의학회지 Vol.41 No.1

Objectives : We examined the association between alcohol consumption and incidence of colorectal cancer in elderly Koreans. Methods : The cohort members (n=14,304) consisted of 4,834 males and 9,470 females derived from the Korea Elderly Pharmacoepidemiologic Cohort (KEPEC), a population-based dynamic cohort. They were aged 65 years old or older and lived in Busan between 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). Baseline information was surveyed by a self-administered, mailed questionnaire. This study population was restricted to 14,304 participants who reported alcohol drinking habits on the questionnaire and had not been diagnosed with colorectal cancer at baseline. The adjusted hazard ratios (aHR) of status, type, frequency and daily average amount of alcohol consumption were computed with Cox's proportional hazard model, with the never-drinkers as a reference group and controlling for age and gender. Results : After 4.82 person-years of mean follow-up 112 cases of colorectal cancer occurred. The incidence densities of colorectal cancer were 161 (95% CI=123-200) for never-drinkers, 219 (95% CI=125-339) for ex-drinkers, and 137 (95% CI=84-189) for current-drinkers per 100,000 person-year. The status, type, frequency, and daily average amount of alcohol consumption were not significantly related to the incidence of colorectal cancer after controlling for age and gender. Conclusions : There was no significant association between alcohol consumption and colorectal cancer among elderly people after controlling for age and gender.

치의학 분야에서의 메타 분석

임회정(Hoi-Jeong Lim) 대한치과의사협회 2014 대한치과의사협회지 Vol.52 No.8

Recently, importance of meta analysis is increasing in the field of dentistry, since it is not easy to settle controversies arising from conflicting studies. Meta analysis is the statistical method of combining results from two or more individual studies that have been done on the same topic. Merits of meta analysis include an increase in power, an improvement in precision, and the ability to address solution not provided by individual studies. However, it might mislead researchers when variation across studies and publication bias are not carefully taken into consideration. The purpose of this study is to help understand meta analysis by making use of individual results in dental research paper.

치주 영역에서 오렌지 데이터마이닝을 활용한 랜덤 포레스트 모델의 단계별 안내

임회정 ( Hoi-jeong Lim ) 대한예방치과·구강보건학회 2021 大韓口腔保健學會誌 Vol.45 No.4

Objectives: The purpose of this study was to show a procedure for a random forest (RF) analysis which predicts periodontal disease status by using R and Orange Data Mining software, and helps us to understand how to apply the RF technique for dental research. Methods: Oral examination data of the 7th Korea National Health and Nutrition Examination Survey were used. A RF model was adopted to analyze the data where the target variable was periodontal disease status and the features were gender, age, education level, marital status, alcohol consumption level, smoking status, brushing before sleep, hypertension, and diabetes-related variables. Results: The important features of the RF analysis were in the order of age, marital status, and prevalence of hypertension and diabetes. The accuracy of the RF analysis was 73% which is not high enough for use in the clinical field. Conclusions: The RF technique is an ensemble method used to predict periodontal disease status which produces higher accurate outputs than a single method. This study provides a step-by-step guide using Orange Data Mining for researchers who want to study machine learning techniques.

치의학 연구에서의 표본크기 산출

임회정(Hoi-Jeong Lim) 대한치과의사협회 2014 대한치과의사협회지 Vol.52 No.9

Sample size determination is critical, but not easy to do. Sample size defined as the number of observations in a sample to be studied should be big enough to have a high likelihood of detecting a true difference between groups. Practical procedure for determining sample size, using G*power and previous dental articles, was shown in this study. Examples involving independent t test, paired t test, one way analysis of variance(ANOVA), and one way repeated measures(RM) ANOVA were used. The purpose of this study is to enable researchers with non statistical backgrounds to use in practice freely available statistical software G*power to determine sample size and power.

치의학 분야에서 SPSS를 이용한 일반화 추정방정식의 단계별 안내

임회정(Hoi-Jeong Lim),박수현(Su-Hyeon Park) 대한치과의사협회 2016 대한치과의사협회지 Vol.54 No.11

The Generalized Estimating Equations (GEE) approach is a widely used statistical method for analyzing longitudinal data and clustered data in clinical studies. In dentistry, due to multiple outcomes obtained from one patient, the outcomes produced from an individual patient are correlated with one another. This study focused on the basic ideas of GEE and introduced the types of covariance matrix and working correlation matrix. The quasi-likelihood information criterion (QIC) and quasi-likelihood information criterion approximation (QICu) were used to select the best working correlation matrix and the best fitting model for the correlated outcomes. The purpose of this study is to show a detailed process for the GEE analysis using SPSS software along with an orthodontic miniscrew example, and to help understand how to use GEE analysis in dental research.

안면비대칭 3차원 CT 분석

윤숙자,임회정,강병철,황현식,Yoon, Suk-Ja,Lim, Hoi-Jeong,Kang, Byung-Cheol,Hwang, Hyeon-Shik 대한영상치의학회 2007 Imaging Science in Dentistry Vol.37 No.1

Purpose : This study aimed to identify the range of normal facial asymmetry using three-dimensional CT and to develop a simple method of diagnosis of facial asymmetry. Materials and Methods : Twenty eight adults with normal occlusion (16 males and 12 females; mean age 24 years and 1 month) were selected whose faces were assessed to be symmetric by an orthodontist. Three-dimensional reconstructions were obtained utilizing spiral CT scans and an oral and maxillofacial radiologist evaluated nineteen anatomic landmarks in three-dimensional coordinates. Facial asymmetry index of each landmark was caluculated. Results : The range of normal facial asymmetry of each landmark was identified using mean and standard deviation of facial asymmetry index. Conclusions : The range of normal facial asymmetry identified in this study may be used as a diagnostic standard for facial asymmetry analysis.

치의학 연구에서 R program을 이용한 성향점수매칭의 단계적 안내

안화연(Hwayoen An),임회정(Hoi-Jeong Lim) 대한치과의사협회 2020 대한치과의사협회지 Vol.58 No.3

The propensity score matching method is a statistical method used to reduce selection bias in observational studies and to show effects similar to random allocation. There are many observational studies in dentistry research, and differences in baseline covariates between the control and case groups affect the outcome. In order to reduce the bias due to confounding variables, the propensity scores are used by equating groups based on the baseline covariates. This method is effective, especially when there are many covariates or the sample size is small. In this paper, the propensity score matching method was explained in a simple way with a dental example by using R software. This simulated data were obtained from one of retrospective study. The control group and the case group were matched according to the propensity score and compared before and after treatment. The propensity score matching method could be an alternative to compensate for the disadvantage of the observation study by reducing the bias based on the covariates with the propensity score.

치의학 연구에서 RevMan을 이용한 이분형 결과변수를 분석하기 위한 메타분석의 단계적 안내

박수현(Su-Hyeon Park),임회정(Hoi-Jeong Lim) 대한치과의사협회 2018 대한치과의사협회지 Vol.56 No.1

Meta-analysis is a statistical method that combines the results of individual studies on the same topic. This method is becoming popular, due to providing the combined result that individual studies cannot provide and giving a more precise result. Despite meta-analysis having such significance, there were few Korean guides for the use of the Review Manager (RevMan) software. This study will provide a step-by-step guide, using orthodontic mini-screw as a dental example, to help researcher carry out metaanalysis more easily and accurately.

토픽모델링과 네트워크 분석을 이용한 자율 주행 윤리 연구 동향 분석

김강민(Kang-Min Kim),임회정(Hoi-Jeong Lim) 한국디지털콘텐츠학회 2024 한국디지털콘텐츠학회논문지 Vol.25 No.1