• The Korean Journal of Applied Statistics
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• v.30 no.4
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• pp.539-553
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• 2017

We propose a multi-state model to analyze semi-competing risks data with interval-censored or missing intermediate events. This model is an extension of the three states of the illness-death model: healthy, disease, and dead. The 'diseased' state can be considered as the intermediate event. Two more states are added into the illness-death model to incorporate the missing events, which are caused by a loss of follow-up before the end of a study. One of them is a state of the lost-to-follow-up (LTF), and the other is an unobservable state that represents an intermediate event experienced after the occurrence of LTF. Given covariates, we employ the Lin and Ying additive hazards model with log-normal frailty and construct a conditional likelihood to estimate transition intensities between states in the multi-state model. A marginalization of the full likelihood is completed using adaptive importance sampling, and the optimal solution of the regression parameters is achieved through an iterative quasi-Newton algorithm. Simulation studies are performed to investigate the finite-sample performance of the proposed estimation method in terms of empirical coverage probability of true regression parameters. Our proposed method is also illustrated with a dataset adapted from Helmer et al. (2001).

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.2
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• pp.1-11
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• 2022

Purpose : This study was conducted to assess the status of sarcopenia and locomotive syndrome in the Korean elderly population over 65 years of age by applying the recently updated screening tool for diagnostic evaluation of sarcopenia and locomotive syndrome. Methods : Sarcopenia and locomotive syndrome (LS) were diagnosed and evaluated in 210 Korean elderly people over 65 years of age. There were 36 patients in the "sarcopenia group", 164 in the "locomotive syndrome group", and 10 in the "normal group". The collected data were analyzed using the chi-square and Kruskal-Wallis tests. Results : The diagnostic evaluation of sarcopenia and LS showed the presence of sarcopenia in 9.05 % of males and 8.10% females among the Korean elderly population over 65 years of age. Prevalence of stage 1 locomotive syndrome (LS 1) was 95.24 %; stage 2, (LS 2) 36.19 %; and stage 3 (LS 3), 16.19 % among the study population. Both the sarcopenia diagnostic indicator and the LS evaluation indicators showed significant differences between the three groups. All the subjects in the sarcopenia group had LS; further, on comparison of the detailed composition ratio of each patient with LS, the prevalence of LS in the sarcopenia group was found to be: LS 1 41.67 %, LS 2 41.67 %, and LS 3 16.67 %, whereas in the LS group, it was found to be: LS 1 66.46 %, LS 2 16.46 %, and LS 3 17.07 %. The difference between the two groups was statistically significant. Conclusion : It was confirmed that sarcopenia is correlated with LS incidence. This suggests that the evaluation of motor LS can be used as a tool for the early diagnosis and prevention of sarcopenia in cases of functional decline due to aging in the elderly population.

• 한국노년학
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• v.30 no.3
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• pp.831-842
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• 2010

BACKGROUND: Sarcopenic obesity(SO), a condition of the reduction in muscle mass paired with an increased fat mass has been paid attention because of its association with disability in later life. A few evidence, however, has reported the association with these factors. PURPOSE: To explore the association among SO, physical function and fitness in older women. METHOD: 257 older women(age of 74) were recruited from Y city and 7 physical functions and 4 fitness tests were measured. Participants were classified into one of four groups based on their body fat and muscle mass: Normal group (GR-A), high fat(GR-B), sarcopenia(GR-C), and sarcopenic obese(GR-D). GLMand LSD-test were conducted with SPSS 12.0. RESULTS: Chair stand, arm-curl, back-scratch, 2-min steps of GR-A was higher than GR-C and GR-D(p<.05). One-leg stand of GR-A was higher than GR-D(p<.01) and of GR-C was higher than GR-D(p<.01).8ft-TUG of GR-D was lower than GR-A(p<.01). Grip strength, knee extension of GR-A was higher than that of GR-C and GR-D(p<.01) and knee flexion of GR-A was also higher than that of GR-C and GR-D(p<.01). CONCLUSION: Based on our findings, we conclude that SO is significantly associated with lower physical function and fitness in older Korean women, which alarm the risk of frailty induced by SO.