• Title/Summary/Keyword: Cox Model

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The Effects of a Horticultural Program based on Cox's Interaction Model on Ability for Daily Life and Depression in Older Patients with Mild Dementia (Cox의 상호작용이론을 근거로 한 원예활동 프로그램이 경증치매노인의 일상생활수행능력 및 우울에 미치는 효과)

  • Yoon, Mi Jin;Sung, Kyung Mi
    • The Korean Journal of Rehabilitation Nursing
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    • v.20 no.1
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    • pp.12-21
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    • 2017
  • Purpose: This study attempts to examine the effects of a horticultural program on activities of daily living (ADL) and depression among older patients with mild dementia. Methods: This study adopted a quasi-experimental design-based nonequivalent control group pretest and posttest design, enrolling 30 older patients with mild dementia. The Korean Form of Geriatric Depression Scale was utilized, while the data was collected from the experimental group for 60 minutes, twice weekly for 6 weeks in 12 sessions. ADL and depression were assessed for both the experimental and the control group. Overall functions were assessed only for the experimental group. Results: The experimental group showed improvement in physical function, cognitive function, as well as psychological, emotional function and social function following each session (p<.001). The horticulture program was effective in both ADL ($Z^2=5.65$, p<.001) and depression (t=-5.24, p<.001). Conclusion: In this study, the horticultural therapy based on the Cox's interaction model had positive effects for older patients with mild dementia. Therefore, horticultural therapy may be commendably applied to older patients with mild dementia as a nursing intervention.

A Study on the Effect of Box-Cox Power Transformation in AR(1) Model

  • Jin Hee;I, Key-I
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.97-106
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    • 2000
  • In time series analysis we generally use Box-Cox power transformation for variance stabilization. In this paper we show that order estimator and one step ahead forecast of transformed AR(1) model are approximately invariant to those of the original model under some assumptions. A small Monte-Carlo simulation is performed to support the results.

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Goodness of Fit Tests of Cox's Proportional Hazards Model

  • Song, Hae-Hiang;Lee, Sun-Ho
    • Journal of the Korean Statistical Society
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    • v.23 no.2
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    • pp.379-402
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    • 1994
  • Graphical and numerical methods for checking the assumption of proportional hazards of Cox model for censored survival data are discussed. The strenths and weaknessess of several goodness of fit tests for the propotional hazards for the two-sample problem are evaluated with Monte Carlo simulations, and the tests of Schoenfeld (1980), Andersen (1982), Wei (1984), and Gill and Schumacher (1987) are considered. The goodness of fit methods are illustrated with the survival data of patients who had chronic liver disease and had been treated with the endoscopy injection sclerotheraphy. Two other examples of data known to have nonpropotional hazards are also used in the illustration.

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Estimating causal effect of multi-valued treatment from observational survival data

  • Kim, Bongseong;Kim, Ji-Hyun
    • Communications for Statistical Applications and Methods
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    • v.27 no.6
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    • pp.675-688
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    • 2020
  • In survival analysis of observational data, the inverse probability weighting method and the Cox proportional hazards model are widely used when estimating the causal effects of multiple-valued treatment. In this paper, the two kinds of weights have been examined in the inverse probability weighting method. We explain the reason why the stabilized weight is more appropriate when an inverse probability weighting method using the generalized propensity score is applied. We also emphasize that a marginal hazard ratio and the conditional hazard ratio should be distinguished when defining the hazard ratio as a treatment effect under the Cox proportional hazards model. A simulation study based on real data is conducted to provide concrete numerical evidence.

New Anti-Inflammatory Formulation Containing Synurus deltoides Extract

  • Choi, Yong-Hwan;Son, Kun-Ho;Chang, Hyeun-Wook;Bae, Ki-Hwan;Kang, Sam-Sik;Kim, Hyun-Pyo
    • Archives of Pharmacal Research
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    • v.28 no.7
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    • pp.848-853
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    • 2005
  • Synurus deltoides was previously found to possess significant anti-inflammatory activity especially against chronic inflammation, and strong analgesic activity in vivo. In this study, new anti-inflammatory formulation containing S. deltoides extract as a major ingredient was prepared and in vivo activity was evaluated. The plausible action mechanism was also investigated. The new formulation (SAG) contains 1 part of S. deltoides extract, 0.9 part of Angelica gigas extract and 0.9 part of glucosamine sulfate (w/w). SAG inhibited dose-dependently edematic response of arachidonic acid (AA)- and 12-O-tetradecanoyl 13-acetate (TPA)-induced ear edema in mice, which is an animal model of acute inflammation. SAG showed 44.1 % inhibition of AA-induced ear edema at an oral dose of 50 mg/kg. In an animal model of chronic inflammation, SAG clearly reduced the edematic response of 7 -day model of multiple treatment of TPA (38.1 % inhibition at 200 mg/kg/day). Furthermore, SAG (50-800 mg/kg/day) as well as S. deltoides extract (285 mg/kg/day) significantly inhibited prostaglandin $E_2$ production from the skin lesion of the animals of 7-day model. These results were well correlated with in vitro finding that SAG as well as S. deltoides extract reduced cyclooxygenase (COX)-1- and COX-2-induced prostanoid production, measured in mouse bone marrow-derived mast cells. Therefore, these results suggest that SAG possesses anti-inflammatory activity in vivo against acute as well as chronic inflammatory animal models at least in part by inhibition of prostaglandin production through COX-1/COX-2 inhibition. And COX inhibition of SAG is possibly contributed by S. deltoides extract among the ingredients. Although the anti-inflammatory potencies of SAG were less than those of currently used anti-inflammatory drugs, this formulation may have beneficial effect on inflammatory disorders as a neutraceutical.

New screening method for anti-inflammatory agent (Cyclooxygenase 억제제 검색을 통한 항염증제 개발 연구)

  • Lee, Su-Hwan;Jeong, Seong-Won;Lee, U-Yeong
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.20 no.1
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    • pp.25-36
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    • 1994
  • It is weal known that bacterial lipopolysaccharide (LPS) stimulates prostaglandin synthesis in various experimental system via enhancing the expression of cylooxygenase-2 (COX-2). This study was designed to characterize U)5-induced prostaglandin synthesis in mouse peritoneal macrophages LPS-stimulated prostaglandin synthesis in macrophages with short term exposure was not so much prominent, but there was a burst in prostaglandin synthesis 8 hours after the LPS treatment and this u·as accompanied with the increase of cyclooxygenase activity, Dexamethasone markedly inhibited prostaglandin synthesis in this system. Metabolic label ins data supported above observations and thus, it could be concluded that LPS induces the do novo synthesis of COX-2 by which it stimulates the prostaglandin synthesis in mouse peritoneal macrophages, These data suggested that this experimental model system could be used for the screening procedure of COX-2 selective inhibitors. Ketoprofen, a non steroidal anti inflammatory agent, appeared to inhibit COX-1 relatively more selectively than COX-2.

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Effects of a Health Promotion Program on College Students Who are on the Brink of Dyslipidemia, Based on Cox's Interaction Model (Cox의 상호작용 모델에 근거한 이상지질혈증 경계범위 대학생의 건강증진 프로그램 효과)

  • Lee, Hye-Kyung;Park, Yeon-Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3058-3068
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    • 2014
  • This experimental research is aimed to apply a health promotion program based on Cox's interaction model to such college students as are on the brink of dyslipidemia, so as to investigate the effects of the program on the subjects' blood lipid indexes including total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoproteins (LDL). The subjects are 39 in all including the experimental group comprising 20 and the control group comprising 19. The analyses applied include descriptive statistics using SPSS WIN 18.0, $X^2$-test, independent t-test, and paired t-test. By means of nursing interventions which are an element of client-professional interaction, the following were offered including health information (exercise management, dietary management, health education), emotional support (sharing of experiences, encouragement, self expression), decision-making controlling (counselling by phone), and professional/ technical abilities; and blood lipid indexes were measured before and after the interventions. The results of this research found that TC, TG and LDL decreased significantly and HDL increased significantly in the experimental group, which indicates that the health promotion program was effective.

The Effects of Cyclooxygenase-2(COX-2) Inhibitor on COX-2 and Prostaglandin E2 Expression in Ovalbumin Induced Early Phase Bronchoconstriction of Rats (Ovalbumin으로 유발된 백서의 즉시형 기관지 수축 반응에서 Cyclooxygenase-2(COX-2) 발현 양상 및 혈중 프로스타글란딘 E2 농도와 COX-2 억제제의 효과)

  • Lee, Sung-Yong;Lee, Sin-Hyung;Jung, Ki-Hwan;Kim, Byung-Gyu;Jung, Hae-Chul;Kim, Kyung-Kyu;Kwon, Young-Hwan;Kim, Ja-Hyeong;Lee, Ju-Han;Lee, Sang-Youb;Cho, Jae-Yoen;Shim, Jae-Joeng;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.2
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    • pp.191-202
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    • 2000
  • Background: Bronchial asthma is characterized by airway hyperresponsiveness(BHR) and inflammation. The cyclooxygenase(COX) is believed to be one of the important enzymes in these inflammatory reactions. Recently, the COX was divided into two isoforms, COX1 and COX2. COX2 is induced by lipopolysaccharide and some cytokines at the inflammation site. Prostaglandin E2(PGE2), produced from COX2, may affect airway inflammation. The purpose of this study is to evaluate the effect of COX2 inhibitor on COX2 expression, plasma PGE2, airway resistance and histologic finding in an animal asthma model. Methods : Sprague-Dawley rats were divided into 3 groups. The normal control group did not receive any treatment, but the asthma control group was sensitized by ovalbumin but not treated with the COX2 inhibitor(nimesulide, Mesulid$^{(R)}$). The treatment group was sensitized and treated with nimesulide. Specific airway resistance(sRaw) before and after nimesulide ingestion was investigated. The PGE2 level in the plasma was examined and COX2 immunogold-silver stain on lung tissue was performed. Results: sRaw and eosionophilic infiltration on airway, which increased in the asthma control group, was compared to normal control(p=0.014). However, there was no difference in eosinophilic infiltration between asthma control and treatment groups(p=0.408) and no difference in COX2 expression on bronchiolar epithelium among the three groups. Plasma PGE2 levels were not statically different among the three groups. Conclusion: The role of COX2 in the allergen-induced BHR was not significant The effect of nimesulide was not observed on BHR, COX2 expression, and plasma PGE2 level. Therefore, COX2 may not be a major substance of allergic asthma.

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Result of Cox Maze Procedure with Bipolar Radiofrequency Electrode and Cryoablator for Persistent Atrial Fibrillation - Compared with Cut-sew Technique - (양극고주파전극과 냉동프로브를 이용한 지속성 심방세동의 수술 결과 - 절개/봉합술식과 비교 -)

  • Lee, Mi-Kyung;Choi, Jong-Bum;Lee, Jung-Moon;Kim, Kyung-Hwa;Kim, Min-Ho
    • Journal of Chest Surgery
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    • v.42 no.6
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    • pp.710-718
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    • 2009
  • Background: The Cox maze procedure has been used as a standard surgical treatment for atrial fibrillation for about 20 years. Recently, the creators have used a bipolar radiofrequency electrode (Cox maze IV procedure) instead of the incision and suture (cut-sew) technique to make atrial ablation lesions for persistent atrial fibrillation. We investigated clinical outcomes for the Cox maze procedure with a bipolar radiofrequency electrode and cryoablator in patients with persistent atrial fibrillation, and compared results with clinical outcomes of the cut-sew procedure. Material and Method: Between April 2005 and July 2007, 40 patients with persistent atrial fibrillation underwent Cox maze IV procedure with a bipolar radiofrequency electrode and cryoablator (bipolar radiofrequency group). Surgical outcomes were compared with those of 35 patients who had the cut-sew technique for the Cox maze III procedure. All patients had concomitant cardiac surgery. Postoperatively, the patients were followed up every 1 to 2 months. Result: At 6 months postoperatively, the conversion rate to regular sinus rhythm was not significantly different between the two groups: 95.0% for the bipolar radiofrequency ablation group; 97.1% for the cut-sew technique (p=1.0). At the end of the follow-up period, the conversion rate to regular sinus rhythm was also not significantly different (92.5% vs. 91.6%, p=1.0). In multivariate analysis using a Cox-regression model, the postoperative atrial dimension was an independent determinant of sinus conversion in the bipolar radiofrequency ablation group (hazard ratio 31, p=0.005). In the Cox-regression model for both groups, atrial fibrillation at 6 months postoperatively (hazard ratio 92.24, p=0.003) and the postoperative left atrial dimension (hazard ratio 16.05, p=0.019) were independent risk factors of continuance or recurrence of atrial fibrillation after Cox maze procedures. Aortic cross-clamp time and cardiopulmonary bypass time were significantly shorter in the radiofrequency group than in the cut-sew group. Conclusion: In the Cox maze procedure for patients with persistent atrial fibrillation, the use of bipolar radiofrequency ablation and a cryoablator is as good as the cut-sew technique for conversion to sinus rhythm. The postoperative left atrial dimension is an independent determinant of postoperative continuance and recurrence of atrial fibrillation.

Prognostic Factors for Survival in Patients with Breast Cancer Referred to Omitted Cancer Research Center in Iran

  • Baghestani, Ahmad Reza;Shahmirzalou, Parviz;Zayeri, Farid;Akbari, Mohammad Esmaeil;Hadizadeh, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.12
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    • pp.5081-5084
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    • 2015
  • Background: Breast cancer is a malignant tumor that starts from cells of the breast and is seen mainly in women. It's the most common cancer in women worldwide and is a major threat to health. The purpose of this study was to fit a Cox proportional hazards model for prediction and determination of years of survival in Iranian patients. Materials and Methods: A total of 366 patients with breast cancer in the Cancer Research Center were included in the study. A Cox proportional hazard model was used with variables such as tumor grade, number of removed positive lymph nodes, human epidermal growth factor receptor 2 (HER2) expression and several other variables. Kaplan-Meier curves were plotted and multi-years of survival were evaluated. Results: The mean age of patients was 48.1 years. Consumption of fatty foods (p=0.033), recurrence (p<0.001), tumor grade (p=0.046) and age (p=0.017) were significant variables. The overall 1- year, 3-year and 5-year survival rates were found to be 93%, 75% and 52%. Conclusions: Use of covariates and the Cox proportional hazard model are effective in predicting the survival of individuals and this model distinguished 4 effective factors in the survival of patients.