• 한국농촌간호학회지
• /
• 제16권1호
• /
• pp.18-28
• /
• 2021

Purpose: This study attempted to confirm whether the suicide prevention effect could be achieved by managing the frailty of the elderly in rural areas. Methods: This study is a single-group pre-post study design. The frailty management program was applied twice a week for 12 weeks for the vulnerable elderly in the rural area from 16th April to 31st May in 2020. The program consisted of physical exercise, health education on nutrition management and disease control, cognitive training, and protein drink provision. Results: The average age of the participants was 77.1 years, and they lived alone (88.6%). As a result of providing the program, there were positive results such as increase in body strength (pre 12.27: post 13.27) and weight (pre 58.51: post 59.13), and decrease in depression (pre 4.66: post 1.20), and there was no statistically significant change in quality of life, Time Up & Go, and BMI. Conclusion: Frailty should be managed to prevent suicide in the elderly. It is necessary to expand and apply various programs that combine physical functions and emotional interventions such as health education, and exercise to maintain muscle strength.

• 한국통계학회:학술대회논문집
• /
• 한국통계학회 2004년도 학술발표논문집
• /
• pp.243-248
• /
• 2004

The timings of two successive events of interest may not be measurable, instead it may be right censored or interval censored; this data structure is called doubly censored data. In the study of HIV, two such events are the infection with HIV and the onset of AIDS. These data have been analyzed by authors under the assumption that infection time and induction time are independent. This paper investigates the regression problem when two events arc modeled to allow the presence of a possible relation between two events as well as a subject-specific effect. We derive the estimation procedure based on Goetghebeur and Ryan's (2000) piecewise exponential model and Gauss-Hermite integration is applied in the EM algorithm. Simulation studies are performed to investigate the small-sample properties and the method is applied to a set of doubly censored data from an AIDS cohort study.

• 한국보건간호학회지
• /
• 제30권2호
• /
• pp.247-258
• /
• 2016

Purpose: The purpose of this study was to evaluate the effects of a comprehensive exercise program for the prevention of urinary incontinence (UI), frailty, and depression, as well as the promotion of physical function in community-dwelling elderly female living alone. Methods: A nonequivalent control group pretest-posttest design was employed. The participants were 76 vulnerable elderly female with a mild-to-moderate urinary incontinence. The exercise group completed 12 weeks of a moderate intensity, comprehensive exercise program. Descriptive statistics, independent t-tests and ANCOVA were used for data analysis with SPSS. Results: Upon the completion of the 12-week exercise program, significant improvements for UI symptoms (p=.001), timed up and go (p<.001), frailty (p=.006), and depression (p<.001) were observed, but not for hand grip strength (p=.053). Conclusion: The findings of this study indicate that the 12-week comprehensive exercise program for the prevention of urinary incontinence had positive effects on improving UI symptoms, physical function, levels of frailty and depression in elderly women living alone. More prolonged exercise programs with other types of exercise should be developed for these vulnerable elderly women, and future studies are encouraged to confirm the effect of the comprehensive exercise program in other settings.

• Journal of the Korean Data and Information Science Society
• /
• 제16권4호
• /
• pp.1017-1026
• /
• 2005

We consider the problem of modeling count data where the observation period is determined by the survival time of the individual under study. We assume random effects or frailty model to allow for a possible association between the death times and the counts. We assume that, given a random effect, the death times follow a Weibull distribution with a rate that depends on some covariates. For the counts, given the random effect, a Poisson process is assumed with the intensity depending on time and the covariates. A gamma model is assumed for the random effect. Maximum likelihood estimators of the model parameters are obtained. The model is applied to data set of patients with breast cancer who received a bone marrow transplant. A model for the time to death and the number of supportive transfusions a patient received is constructed and consequences of the model are examined.

• Journal of the Korean Data and Information Science Society
• /
• 제25권2호
• /
• pp.327-336
• /
• 2014

재발 사건 자료란 연구대상이 같은 종류의 사건을 반복적으로 경험할 때 발생하는 자료이다. 이러한 재발 사건은 사회과학, 자연과학, 공학, 의약학 등 다양한 분야에서 나타날 수 있다. 재발 사건자료를 분석할 때 연구자의 관심에 따라 사건 발생시간이나 사건 발생간의 소요시간을 이용하여 분석할 수 있다. 이 논문에서는 사건 발생시점간의 소요시간을 이용하여 불완전한 관측을 가진 재발 사건자료를 분석하고자 한다. 이 자료의 특징은 일부 관측대상들이 일정기간 동안 연구에서 제외되는 관측틈을 갖는다는 것이다. 이 때 관측틈은 불완전한 형태로 나타나게 되는데 그 이유는 관측틈의 시작시점은 알고 있지만 종료시점은 알 수 없기 때문이다. 이러한 미지의 종료시점을 추정하기 위해서 구간 중도 절단 방법이 적용된다. 따라서 종료시점이 추정된 후 프레일티를 포함한 회귀모형을 적용하여 공변량이 사건 재발에 미치는 영향을 알아볼 수 있다. 또한 제안한 방법을 실제자료에 적용하여 관측틈을 고려한 경우와 고려하지 않은 경우를 비교하고자 한다.

• 응용통계연구
• /
• 제23권5호
• /
• pp.871-882
• /
• 2010

동물종양 실험에서는 종양발생 시간이 직접 관찰되지 않고 단지 자연사로 인한 관찰 시점이나 강제적으로 희생시킨 시점 이전에 종양이 발생했는지 유무만을 알 수 있다. 이와 같은 형태의 결측을 가진 자료를 분석하기 위해 3단계(건강$\rightarrow$종양발생$\rightarrow$사망) 모형이 널리 사용되고 있다. 본 논문에서는 자연사로 인한 사망 시간이 종속적인 중도절단으로 작용하여 사망 시간과 종양발생 시간이 종속될 때, 이를 모형에 반영하기 위해 감마 프레일티 효과를 도입하였다. 모수 추정은 종양발생 시간과 프레일티 효과의 결측을 다루기 위해 EM 알고리즘 방법을 사용하였다. 제안한 추정량의 소표본 성질을 살펴보기 위해 제안한 방법을 Lindsey와 Ryan (1993, 1994)의 방광암 자료에 적용하여 모수를 추정하였으며, 그 추정값을 바탕으로 모의실험을 수행하였다.

• Communications for Statistical Applications and Methods
• /
• 제27권1호
• /
• pp.37-46
• /
• 2020

Recurrent event data frequently occur in clinical studies, demography, engineering reliability and so on (Cook and Lawless, The Statistical Analysis of Recurrent Events, Springer, 2007). Sometimes, two or more different but related type of recurrent events may occur simultaneously. In this study, our interest is to estimate the covariate effect on bivariate recurrent event times with zero inflations. Such zero inflation can be related with susceptibility. In the context of bivariate recurrent event data, furthermore, such susceptibilities may be different according to the type of event. We propose a joint model including both two intensity functions and two cure rate functions. Bivariate frailty effects are adopted to model the correlation between recurrent events. Parameter estimates are obtained by maximizing the likelihood derived under a piecewise constant hazard assumption. According to simulation results, the proposed method brings unbiased estimates while the model ignoring cure rate models gives underestimated covariate effects and overestimated variance estimates. We apply the proposed method to a set of bivariate recurrent infection data in a study of child patients with leukemia.

• 응용통계연구
• /
• 제9권2호
• /
• pp.119-134
• /
• 1996

가속수명검사는 시간과 경비를 현실적인 여건에 맞추기 위하여 정상조건보다 열악한(강도가 높은) 조건에서 검사를 수행하여 그 결과를 정상조건에서의 수명분포와 관련된 관심사(기대수명, 신뢰도) 등을 추정하는 것을 목적으로 하는 검사 방법이다. 이 연구에서는 고장률이 다른 두 개의 부품이 직렬형으로 구성된 시스템의 가속수명검사 자료를 분석할 때 사용되는 하나의 모형을 제안하고 분석 과정 및 기존의 두 개의 부품이 서로 독립이라고 가정한 모형과 비교하는 것을 주요 내용으로 하였다. 시스템이 작동될 때 받는 관찰이 가능하지 않은 총체적인 환경의 효과를 동일 시스템내의 두 개의 부품이 공유하게 됨으로써 발생되는 두 부품의 수명의 의존성을 frailty 모형을 이용하여 모형화하였고, 분석 과정에서는 Profile 우도함수를 사용하여 최대 우도 추정 과정에서의 초기치 문제를 해결하는 방법을 제시하고 모의실험을 통하여 독립성의 가정을 검토하여 보았다.

• 지역사회간호학회지
• /
• 제27권1호
• /
• pp.51-59
• /
• 2016

Purpose: The purpose of this study is to provide a disease management, nutrition education, and group exercise program for three months to the moderately frail elderly whose physical functions have deteriorated, and to investigate its effects in order to develop an intervention program. Methods: As a quasi-experiment, this study was conducted based on non-equivalence studies designed as a similar experiment. The milk intake group and calcium intake group participated in the disease education, individual nutrition education, and group exercise program for three months, and the control group was visited once in the three months by a nurse who provided disease education, nutrition education, and oral instruction of exercise, and asked them to exercise on their own every day. For the data analysis, ${\chi}^2$-test, ANOVA and $Scheff{\acute{e}}$ test were used. Results: After three months of intervention, there was a significant difference in the frailty level (p=.029) and bone density (p=.001) between the groups. Conclusion: The comprehensive intervention program had an effect on the bone density and the frailty level of the socially-vulnerable and moderately frail elderly, suggesting that the program can be used as a nursing intervention to prevent functional deterioration and damage of the moderately frail elderly.

• 한국데이터정보과학회:학술대회논문집
• /
• 한국데이터정보과학회 2006년도 PROCEEDINGS OF JOINT CONFERENCEOF KDISS AND KDAS
• /
• pp.37-37
• /
• 2006