• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.47-54
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• 2022

The purpose of this study was to analyze the effect of masticatory ability on frailty in the elderly. General characteristics, subjective and objective masticatory ability, and frailty level were investigated in 224 elderly. The major findings were as; There were differences in masticating ability according to age, education level, employment status, living arrangement, and maxillary & mandibular dentures. The masticatory ability of the non-frail elderly was significantly higher than the frail elderly. The risk ratio of frailty was 2.33 times higher in subjects with poor mastication compared to subjects with good mastication ability. Also, as a result of adjusting for age, the risk ratio of frailty in the poor group was 2.30 times higher than in the group with good mastication ability. Through this, it is thought that the masticatory ability of the elderly is one of the predictors of frailty, and efforts to achieve healthy aging by preventing senescence through oral health management at the community level are thought to be necessary.

• Journal of Korean Academy of Rural Health Nursing
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• v.16 no.1
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• pp.18-28
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• 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.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.243-248
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• 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.

• Journal of Korean Public Health Nursing
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• v.30 no.2
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• pp.247-258
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• 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
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• v.16 no.4
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• pp.1017-1026
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• 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
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• v.25 no.2
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• pp.327-336
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• 2014

Recurrent event data occurs when a subject experiences same type of event repeatedly and is found in various areas such as the social sciences, Economics, medicine and public health. To analyze recurrent event data either a total time or a gap time is adopted according to research interest. In this paper, we analyze recurrent event data with incomplete observation gap using a gap time scale. That is, some subjects leave temporarily from a study and return after a while. But it is not available when the observation gaps terminate. We adopt an interval censoring mechanism for estimating the termination time. Furthermore, to model the association among gap times of a subject, a frailty effect is incorporated into a model. Programs included in Survival package of R program are implemented to estimate the covariate effect as well as the variance of frailty effect. YTOP (Young Traffic Offenders Program) data is analyzed with both proportional hazard model and a weibull regression model.

• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.871-882
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• 2010

In animal tumorigenicity data, the occurrence time of tumor is not observed because the existence of a tumor is examined only at either time of natural death or time of sacrifice for the animal. A three-state model (Health-Tumor onset-Death) is widely used to model the incomplete data. In this paper, we employed a frailty effect into the three-state model to incorporate the dependency of death on tumor occurrence when the time of natural death works as an informative censoring against the tumor onset time. For the inference of parameters, then the EM algorithm is considered in order to deal with missing quantities of tumor onset time and random frailty. The proposed method is applied to the bladder tumor data taken from Lindsey and Ryan (1993, 1994) and a simulation study is performed to show the behavior of the proposed estimators.

• Communications for Statistical Applications and Methods
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• v.27 no.1
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• pp.37-46
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• 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.

• The Korean Journal of Applied Statistics
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• v.9 no.2
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• pp.119-134
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• 1996

Accelerated life testing (ALT) of a system is commonly used to reduce time and cost. ALT is achieved by subjecting the test systems to more severe conditions than the normal ones to obtain estimates of life distribution under normal condition. The major interest of this research is to use a model of incorporating the common environmental effect on the components serially linked into a system-so called frailty model for the system life time distribution under each stress and to discuss the related data analysis and comparison of the model with the generally used one. The profile likelihood is used to get an initial values required to compute maximum likelihood estimates and simulation is carried for comparison.

• Research in Community and Public Health Nursing
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• v.27 no.1
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• pp.51-59
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• 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.