• Communications for Statistical Applications and Methods
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• 제30권4호
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• pp.389-402
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• 2023

Multivariate or clustered failure time data often occur in many medical, epidemiological, and socio-economic studies when survival data are collected from several research centers. If the data are periodically observed as in a longitudinal study, survival times are often subject to various types of interval-censoring, creating multivariate interval-censored data. Then, the event times of interest may be correlated among individuals who come from the same cluster. In this article, we propose a unified linear regression method for analyzing multivariate interval-censored data. We consider a semiparametric multivariate accelerated failure time model as a statistical analysis tool and develop a generalized Buckley-James method to make inferences by imputing interval-censored observations with their conditional mean values. Since the study population consists of several heterogeneous clusters, where the subjects in the same cluster may be related, we propose a generalized estimating equations approach to accommodate potential dependence in clusters. Our simulation results confirm that the proposed estimator is robust to misspecification of working covariance matrix and statistical efficiency can increase when the working covariance structure is close to the truth. The proposed method is applied to the dataset from a diabetic retinopathy study.

• 응용통계연구
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• 제33권5호
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• pp.627-637
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• 2020

본 논문에서는 건강보험심사평가원에서 제공한 약 120만명의 2014년 고령환자의료자료(HIRA-APS-2014-0053)과 기상자료를 일반화추정방정식(generalized estimating equation; GEE) 모형과 long short term memory (LSTM) 기반 순환신경망(recurrent neural network; RNN) 모형으로 분석하여 기상 조건에 따른 주요 주상병의 발생 빈도를 예측한다. 이를 위해 환자가 의료 서비스를 받은 기관의 지역을 이용하여 환자의 거주지를 추정하고 해당 지역의 주별 기상 관측소 자료와 의료자료를 병합하였다. 질병 발생 상태를 세 개의 범주(질병에 걸리지 않음, 관심 주상병 발생, 다른 질병 방생)로 나누었으며 각 범주에 속할 확률을 GEE 모형과 RNN 모형으로 추정하였다. 각 범주별 발생 건수는 해당 범주의 속할 추정확률의 합으로 계산하였으며 비교분석결과 RNN을 이용한 예측이 GEE를 이용한 예측보다 정확도가 높은 것으로 나타났다.

• 한국수자원학회논문집
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• 제49권8호
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• pp.645-656
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• 2016

본 연구에서는 금강유역에 대한 지역홍수빈도분석을 실시하고 재현기간에 따른 홍수량을 추정하는 관계식을 제안하였다. 유역 내 유량자료의 수문학적 독립성과 동질성에 대한 검증을 위하여 Lag-1 자기상관성 분석, 동질성 검정, 이상치 검정, 불일치척도 검정을 수행하였다. 검정 결과, 금강유역의 대상 관측소들은 시간에 대하여 독립적이고 동질적 모집단에 속하며 이상치는 없었다. 일반 극치 분포(GEV), 3변수 대수정규 분포(LN-III), 피어슨-III 분포(P-III), 일반 로지스틱 분포(GLO), 일반 파레토 분포(GPA) 등 5개의 3변수 확률분포함수에 대한 L-모멘트비도와 평균가중거리(AWD), 그리고 $Z^{DIST}$ 적합도 산정 결과, GLO 분포함수가 금강유역의 최적 확률분포형으로 선정되었다. GLO 분포를 바탕으로 지역홍수빈도를 추정하는 회귀모형을 제안하였고, 강경 관측소의 관측 유량을 이용하여 회귀모형의 적용성을 검증하였다.

• 사회복지연구
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• 제48권4호
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• pp.33-57
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• 2017

본 연구는 점증하는 가계부채에 대한 관심과 우려가 커지는 상황에서 가계부채가 부부폭력의 위험에 미치는 영향을 분석하였다. 자료는 한국복지패널 4~11차(2009~2016년) 데이터를 활용하였으며, 분석방법으로는 일반화추정방정식(Generalized Estimating Equations)을 사용하였다. 분석 결과, 가계부채비(가처분소득 대비 총부채액)와 부채상환비(가처분소득 대비 부채상환액)가 높아질수록 부부폭력의 위험도 증가하는 경향이 있었 다. 비빈곤층에서는 높은 부채상환비가, 빈곤층에서는 높은 비우량부채비가 부부폭력의 위험을 높이는 것으로 나타났다. 물질적 결핍의 매개효과 역시 빈곤지위에 따라 달랐는데, 빈곤층에서는 물질적 결핍이 비우량부채비와 부부폭력의 관계를 매개하는 것으로 보이나, 비빈곤층에서는 그러한 관계가 관찰되지 않았다. 이 연구는 경제적 곤란이 부부관계의 질에 영향을 미친다는 가족스트레스모델을 가계부채의 역할에 초점을 맞추어 적용하고, 경제적 곤란을 야기하는 다양한 요인 중 부채 부담 수준이 부부폭력의 위험에 미치는 영향을 실증분석 하였다는데 의미가 있다.

• 보건행정학회지
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• 제32권1호
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• pp.53-62
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• 2022

Background: This study was designed to examine regional proportions for people who experienced unmet health care needs due to reduced mobility or unhealthiness and factors associated with experience of unmet health care needs by them. Methods: A total of 11,620 people were retrieved from the Korea Health Panel data (2014-2018). Regional proportions for people who experienced unmet health care needs due to reduced mobility or unhealthiness were estimated using cross-sectional weights and the factors associated with them were analyzed using generalized estimating equation. Results: The number of people who experienced unmet health care needs due to reduced mobility or unhealthiness was estimated as 278,083 in 2018. Women, the aged (65+), below elementary school, single as marital status, low income, bad self-rated health, people with disabilities, and long-term insurance beneficiaries were statistically significantly associated with experience of unmet health care needs due to reduced mobility or unhealthiness. Conclusion: Given high and dispersed demand for visiting health care, government need to expand the infrastructure and finance to facilitate visiting health care.

• Management Science and Financial Engineering
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• 제12권1호
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• pp.65-77
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• 2006

This study proposes a Bayesian dynamic model in a hierarchical way to assess the time-varying effect of risk factors on the likelihood of corporate bankruptcy. For the longitudinal data, we aim to describe dynamically evolving effects of covariates more articulately compared to the Generalized Estimating Equation approach. In the analysis, it is shown that the proposed model outperforms in terms of sensitivity and specificity. Besides, the usefulness of this study can be found from the flexibility in describing the dependence structure among time specific parameters and suitability for assessing the time effect of risk factors.

• Communications for Statistical Applications and Methods
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• 제23권6호
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• pp.555-562
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• 2016

Interval censored data often occur in an observational study where the subject is followed periodically. Instead of observing an exact failure time, two inspection times that include it are available. There are several methods to analyze interval censored failure time data (Sun, 2006). However, in the presence of competing risks, few methods have been suggested to estimate covariate effect on interval censored competing risk data. A sub-distribution hazard model is a commonly used regression model because it has one-to-one correspondence with a cumulative incidence function. Alternatively, Klein and Andersen (2005) proposed a pseudo-value approach that directly uses the cumulative incidence function. In this paper, we consider an extension of the pseudo-value approach into the interval censored data to estimate regression coefficients. The pseudo-values generated from the estimated cumulative incidence function then become response variables in a generalized estimating equation. Simulation studies show that the suggested method performs well in several situations and an HIV-AIDS cohort study is analyzed as a real data example.

• Journal of Nutrition and Health
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• 제28권1호
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• pp.71-83
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• 1995

The purpose of the study was to develop generalized equations for estimating stature and weight for the nonambulatory elderly persons. Height weight recumbent knee height total ann length, midarm, waist and calf circumferences, triceps and subscapular skinfolds were measured from over 60 years old 315 ambulatory elderly. The equations to predict stature and weight were derived from participants in the validation sample and were applied to the participants in the cross-validation to test the accuracy and validity of equations. Stature and weight were significantly and negatively associated with age of women and similar patterns observed in men but associated to a slight degree. Knee height and total arm length were highly correlated with stature but the majority of the variances in stature was accounted for by knee height for both the men and women. In men, waist circumference was the most significantly correlated with weight and am, calf circumferences and so forth. But in women arm circumference was the highest then waist and calf circumference in order. The possible predictor variables to estimate of stature were knee height total arm length and age for both elderly men and women. Predictor variables to estimate of weight were recumbent measures of waist am, calf circumferences and knee height for both sexes. Inclusion of skinfold thickness measurements did not improve the prediction power of estimation for weight. When both equations developed from the present study and Chumlea's study were applied to cross-valida-tions samples, the equations derived from present study showed better accuracy and validity. The presentation of prediction equations using two, three, or four recommended measurements allows the selection of an equation based upon the measurements that are possible to collect on an individual basis.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.4067-4076
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• 2015

본 연구는 2008년~2011년 "한국의료패널" 원시자료를 이용하여 연간 가구 과부담 의료비 지출 추이와 과부담 의료비 발생에 영향을 미치는 요인을 알아보고자 하였다. 연도별 과부담 의료비 발생률 추이는 교차분석(correspondence analysis)을 실시하였고, 과부담 의료비 발생에 영향을 미치는 요인은 일반화 추정방정식(generalized estimating equation)을 이용하였다. 연간 과부담 의료비 발생률 추이는 10%, 15%, 20%, 30%, 40% 역치 수준에서 각각 평균 25.1%, 15.4%, 10.1%, 5.4%, 3.2%로 나타났다. 과부담 의료비 발생에 영향을 미치는 요인을 살펴본 결과, 연간 총가구소득이 낮을수록, 가구주의 교육수준이 낮을수록, 의료보장형태가 건강보험가입 가구일수록, 가구주가 장애가 있을수록, 가구주의 연령이 높아질수록, 총가구원 수가 적을수록, 가구원의 주관적 건강수준이 낮을수록, 가구당 만성질환 유병률이 높을수록 과부담 의료비 발생 확률이 높게 나타났다(p<0.05). 따라서 의료 접근성 향상을 위한 전반적인 보장성 확대를 위한 노력과 동시에 특히 의료비 부담이 큰 노인 가구, 만성질환 가구 등의 취약계층을 우선으로 고려하는 정책 마련이 필요하다.

• 보건행정학회지
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• 제31권1호
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• pp.125-139
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• 2021

Background: In Korea, the health gap widens due to the number of medical resources and access to medical services between metropolitan and rural. The purpose of this study is to identify the impact of residential migration on medical utilization and accessibility. Methods: This study extracted 528,516 claimed cases in the National Health Insurance Service-Cohort Sample Database from 2006 to 2015. Subjects were classified into two groups by the magnitude of the region, the metropolitan and the rural. The inversed probability weights were calculated for each group. And coefficients of the two-part model were estimated by generalized estimation equation. Results: Those who moved region from metropolitan to rural tend to increase the length of stay and inpatients with ambulatory care sensitive conditions (ACSC) disease. Contrariwise, those who moved areas from rural to metropolitan tend to decrease the total medical cost, the adjusted patient days, the number of outpatients and the number of outpatients and inpatients with ACSC disease. Conclusion: This study identified that between the residents who continued to reside in the region and the migrants, there were significant differences in the medical accessibility, quality of primary care, and unmet medical need.