• Title/Summary/Keyword: Proportional hazards

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Cohort Study on Age at Menopause and Mortality - Kangwha Cohort Study - (폐경 연령과 사망력과의 관계에 대한 코호트 연구 - 강화 코호트 연구 -)

  • Hong, Jae-Seok;Yi, Sang-Wook;Jee, Sun-Ha;Sohn, Tae-Yong;Ohrr, Hee-Choul
    • Journal of Preventive Medicine and Public Health
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    • v.34 no.4
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    • pp.323-330
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    • 2001
  • Objective : To examine the association between age at menopause and mortality in a population-based sample of women in Kangwha, Korea. Methods : From the Kangwha Cohort, followed-up from 1985 to 1999, the data of the over 55 year old female group(n=3,596) was used in this study to examine the association between age at menopause and mortality. We calculated the all causes mortality risk ratio and the cancer mortality risk ratio by age at menopause grouping using the Cox Proportional Hazards Model with adjustments for age, BMI, smoking, education, chronic disease, self-rated health status, alcohol consumption and age at first birth. Result and conclusion : Compared to women who had menopause at 45-49 years, the all causes mortality risk ratio was 1.24 for women with menopause at less than 40 years(95% CI=1.01-1.53) and 1.05 for women with menopause at over 50 years(95% CI=0.92-1.20). Also, compared to women who had menopause at 45-49 years, the cancer mortality risk ratio was 1.53 for women with menopause at less than 40 years(95% CI=0.78-2.98) and 1.17 for women with menopause at over 50 years(95% CI=0.77-1.80).

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Reappraisal of Anatomic Outcome Scales of Coiled Intracranial Aneurysms in the Prediction of Recanalization

  • Lee, Jong Young;Kwon, Bae Ju;Cho, Young Dae;Kang, Hyun-Seung;Han, Moon Hee
    • Journal of Korean Neurosurgical Society
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    • v.53 no.6
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    • pp.342-348
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    • 2013
  • Objective : Several scales are currently used to assess occlusion rates of coiled cerebral aneurysms. This study compared these scales as predictors of recanalization. Methods : Clinical data of 827 patients harboring 901 aneurysms treated by coiling were retrospectively reviewed. Occlusion rates were assessed using angiographic grading scale (AGS), two-dimensional percent occlusion (2DPO), and volumetric packing density (vPD). Every scale had 3 categories. Followed patients were dichotomized into either presence or absence of recanalization. Kaplan-Meier analysis was conducted, and Cox proportional hazards analysis was performed to identify surviving probabilities of recanalization. Lastly, the predictive accuracies of three different scales were measured via Harrell's C index. Results : The cumulative risk of recanalization was 7% at 12-month, 10% at 24-month, and 13% at 36-month of postembolization, and significantly higher for the second and third categories of every scale (p<0.001). Multivariate-adjusted hazard ratios (HRs) of the second and third categories as compared with the first category of AGS (HR : 3.95 and 4.15, p=0.004 and 0.001) and 2DPO (HR : 4.87 and 3.12, p<0.001 and 0.01) were similar. For vPD, there was no association between occlusion rates and recanalization. The validated and optimism-adjusted C-indices were 0.50 [confidence (CI) : -1.09-2.09], 0.47 (CI : -1.10-2.09) and 0.44 (CI : -1.10-2.08) for AGS, 2DPO, and vPD, respectively. Conclusion : Total occlusion should be reasonably tried in coiling to maximize the benefit of the treatment. AGS may be the best to predict recanalization, whereas vPD should not be used alone.

Clinical Prognostic Score for Predicting Disease Remission with Differentiated Thyroid Cancers

  • Somboonporn, Charoonsak;Mangklabruks, Ampica;Thakkinstian, Ammarin;Vatanasapt, Patravoot;Nakaphun, Suwannee
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.6
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    • pp.2805-2810
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    • 2016
  • Background: Differentiated thyroid cancer is the most common endocrine malignancy with a generally good prognosis. Knowing long-term outcomes of each patient helps management planning. The study was conducted to develop and validate a clinical prognostic score for predicting disease remission in patients with differentiated thyroid cancer based on patient, tumor and treatment factors. Materials and Methods: A retrospective cohort study of 1,217 differentiated thyroid cancer patients from two tertiary-care hospitals in the Northeast of Thailand was performed. Associations between potential clinical prognostic factors and remission were tested by Cox proportional-hazards analysis in 852 patients (development cohort). The prediction score was created by summation of score points weighted from regression coefficients of independent prognostic factors. Risks of disease remission were estimated and the derived score was then validated in the remaining 365 patients (validation cohort). Results: During the median follow-up time of 58 months, 648 (76.1%) patients in the development cohort had disease remission. Five independent prognostic factors were identified with corresponding score points: duration from thyroid surgery to $^{131}I$ treatment (0.721), distant metastasis at initial diagnosis (0.801), postoperative serum thyroglobulin level (0.535), anti-thyroglobulin antibodies positivity (0.546), and adequacy of serum TSH suppression (0.293). The total risk score for each patient was calculated and three categories of remission probability were proposed: ${\leq}1.628$ points (low risk, 83% remission), 1.629-1.816 points (intermediate risk, 87% remission), and ${\geq}1.817$ points (high risk, 93% remission). The concordance (C-index) was 0.761 (95% CI 0.754-0.767). Conclusions: The clinical prognostic scoring model developed to quantify the probability of disease remission can serve as a useful tool in personalized decision making regarding treatment in differentiated thyroid cancer patients.

Weight Loss as a Nonpharmacologic Strategy for Erosive Esophagitis: A 5-Year Follow-up Study

  • Bang, Ki Bae;Park, Jung Ho
    • Gut and Liver
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    • v.12 no.6
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    • pp.633-640
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    • 2018
  • Background/Aims: Obesity is a risk factor for gastroesophageal reflux disease (GERD), with several studies demonstrating positive associations between body mass index (BMI) and GERD symptoms. However, little is known about the effect of BMI changes on erosive esophagitis (EE). In this study, we investigated whether BMI reduction could resolve EE. Methods: A retrospective cohort study was performed to assess the natural course of EE according to changes in BMI. Participants undergoing health check-ups from 2006 to 2012 were enrolled, and 1,126 subjects with EE were included. The degree of esophagitis was measured by upper endoscopy and serially checked over a 5-year follow-up. Logistic regression and Cox proportional hazards models were used to investigate the association between BMI reduction and EE resolution. Results: Substantial weight loss is associated with EE resolution. The adjusted odds ratio for EE resolution was 1.44 (95% confidence interval [CI], 1.09 to 1.92) among participants with a decrease in BMI compared to those with no decrease in BMI. The EE resolution rate was related to the degree of BMI reduction. The effect of weight loss on EE resolution was higher among subjects who lost more weight. Compared with subjects with no decrease in BMI, the hazard ratios for EE resolution were 1.09 (95% CI, 0.89 to 1.35), 1.31 (95% CI, 1.01 to 1.72) and 2.12 (95% CI, 1.44 to 3.12) in subjects with BMI reductions of ${\leq}1$, 1-2, and >$2kg/m^2$, respectively. Conclusions: EE resolution is associated with a decrease in BMI, and weight loss is potentially an effective GERD treatment.

End-stage Renal Disease and Risk of Active Tuberculosis: a Nationwide Population-Based Cohort Study

  • Min, Jinsoo;Kwon, Soon Kil;Jeong, Hye Won;Han, Joung-Ho;Kim, Yeonkook Joseph;Kang, Minseok;Kang, Gilwon
    • Journal of Korean Medical Science
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    • v.33 no.53
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    • pp.341.1-341.11
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    • 2018
  • Background: The converging epidemics of tuberculosis (TB) and end-stage renal disease (ESRD) have generated a significant public health burden, however, previous studies have been limited to a small number of patients. This nationwide cohort study aimed to assess the rate of developing active TB among patients receiving dialysis for ESRD. Methods: The Korean national health insurance database was used to identify patients receiving dialysis for new-onset ESRD during 2004-2013, who were propensity score matched to an equivalent number of non-dialysis subjects from the general population. The incidences of active TB in the ESRD and control cohorts were calculated for 2004-2013, and multivariable Cox proportional hazards model was used to evaluate the ESRD-related risk of active TB. Results: During 2004-2013, 59,584 patients received dialysis for newly diagnosed ESRD. In the dialysis and control cohorts, 457 (0.8%) and 125 (0.2%) cases of active TB were detected, respectively. Patients with ESRD were associated with a significantly higher risk of active TB compared to the controls (incidence rate ratio, 4.80). The ESRD cohort had an independently elevated risk of active TB (adjusted hazard ratio, 4.39; 95% confidence interval, 3.60-5.37). Conclusion: We found that patients receiving dialysis for ESRD had an elevated risk of active TB. These results highlight the need for detailed and well-organised guidelines for active TB screening among patients with ESRD.

Duration of Abstinence after Discharge from Alcoholism Inpatient Treatment - Comparing Voluntarily vs. Involuntarily Admitted Patients - (알코올중독자의 입원동의 여부에 따른 퇴원후 단주기간에 관한 연구)

  • Rhee, Chaie-Won
    • Korean Journal of Social Welfare Studies
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    • no.39
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    • pp.57-81
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    • 2008
  • Motivation has been identified as an important factor predicting long-term outcomes of alcohol abuse treatment. Whether a patient agreed on his/her inpatient treatment at time of hospitalization could be an indicator of their motivation for treatment. This study focused on this aspect of treatment motivation and examined whether this factor predicts post-discharge abstinence. A sample of 145 individuals who were hospitalized for alcohol abuse treatment participated in the baseline data collection, of which only 66 successfully completed the 8 month follow-up telephone interview. The findings of survival analysis suggest that voluntarily admitted individuals had significantly longer duration of post-discharge abstinence compared to their counterparts. A Cox proportional hazards regression model revealed that voluntary admission and family support were significant predictors for post-discharge relapse of drinking, after controlling for the effects of marital status, living alone, and working status. Implications for social work practice are discussed.

Implant survival and risk factor analysis in regenerated bone: results from a 5-year retrospective study

  • Hong, Ji-Youn;Shin, Eun-Young;Herr, Yeek;Chung, Jong-Hyuk;Lim, Hyun-Chang;Shin, Seung-Il
    • Journal of Periodontal and Implant Science
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    • v.50 no.6
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    • pp.379-391
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    • 2020
  • Purpose: The aims of this study were to evaluate the 5-year cumulative survival rate (CSR) of implants placed with guided bone regeneration (GBR) compared to implants placed in native bone, and to identify factors contributing to implant failure in regenerated bone. Methods: This retrospective cohort study included 240 patients who had implant placement either with a GBR procedure (regenerated bone group) or with pristine bone (native bone group). Data on demographic features (age, sex, smoking, and medical history), location of the implant, implant-specific features, and grafting procedures and materials were collected. The 5-year CSRs in both groups were estimated using Kaplan-Meier analysis. Risk factors for implant failure were analyzed with a Cox proportional hazards model. Results: In total, 264 implants in the native bone group and 133 implants in the regenerated bone group were analyzed. The 5-year CSRs were 96.4% in the regenerated bone group and 97.5% in the native bone group, which was not a significant difference. The multivariable analysis confirmed that bone status was not an independent risk factor for implant failure. However, smoking significantly increased the failure rate (hazard ratio, 10.7; P=0.002). Conclusions: The 5-year CSR of implants placed in regenerated bone using GBR was comparable to that of implants placed in native bone. Smoking significantly increased the risk of implant failure in both groups.

A Study on Risk of the Incidence of Lung Cancer in a Horse Trainer Using National Health Insurance Service (마필관리사에서 발생한 폐암 위험도 연구: 건강보험공단 빅데이터 12년 추적 연구)

  • Lee, Seunghyun;Kim, Seunghan;Yun, Sehyun;Kim, KyooSang;Yoon, Jin-Ha
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.31 no.4
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    • pp.378-384
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    • 2021
  • Objectives: Horse trainers ensure the horses they are training and monitor horse's health, hygiene. While most of the studies on horse trainer's health focused on musculoskeletal disorders, few studies have examined the health effect of occupational exposure. This study aimed to investigate the risk of lung cancer in Korean Horse trainers. Methods: Among the largest health screening program of health screening service of the National Health Insurance Corporation, 2,246 workers were selected for study. We utilized data from the National Health Insurance Service (NHIS) National Cohort Data Base 2005-2017. We performed analyses using a Cox's proportional hazards model to identify the risk of lung cancer in Horse trainers. Results: This study found that the horse trainers group had a higher risk of lung cancer 10.07 (95% CI :2.38-42.64) compared to other occupational group. Additionally, there was 6.5 times higher risk of lung cancer in non-smoker horse trainers group. Conclusions: We, thus, verified horse trainers could have relation with increase of lung cancer risk. As lung cancer is known as a cancer with a high contribution of occupational factors compared to other cancers, it is necessary to determine the efficacy of continuous attention and active management of occupational exposure.

Clinicopathologic correlation with MUC expression in advanced gastric cancer

  • Kim, Kwang;Choi, Kyeong Woon;Lee, Woo Yong
    • Korean Journal of Clinical Oncology
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    • v.14 no.2
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    • pp.89-94
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    • 2018
  • Purpose: To investigate the relationship between MUC expression and clinicopathologic factors in advanced gastric cancer. Methods: A total of 237 tumor specimens were assessed for MUC expression by immunohistochemistry. The clinicopathologic factors were investigated with MUC1, MUC2, MUC5AC, and MUC6. Results: MUC1, MUC2, MUC5AC, and MUC6 expression was identified in 148 of 237 (62.4%), 141 of 237 (59.5%), 186 of 237 (78.5%), and 146 of 237 (61.6%) specimens, respectively. MUC1 expression was correlated with age, human epidermal growth factor receptor 2 (HER2) status, lymphatic invasion, Lauren classification and histology. Further multivariate logistic regression analysis revealed a significant correlation between MUC1expression and lymphatic invasion, diffuse type of Lauren classification. MUC5AC expression was correlated with HER2 status, Lauren classification and histology. Further multivariate logistic regression analysis revealed a significant correlation between MUC5AC expression and HER2 status, diffuse and mixed type of Lauren classification. MUC2 and MUC6 expression were not correlated with clinicopathologic factors. The patients of MUC1 expression had poorer survival than those without MUC1 expression, but MUC2, MUC5AC or MUC6 were not related to survival. In an additional multivariate analysis that used the Cox proportional hazards model, MUC1 expression was not significantly correlated with patient survival independent of age, N-stage, and venous invasion. Conclusion: When each of these four MUCs expression is evaluated, in light of clinicopathologic factors, MUC1 expression may be considered as a prognostic factor in patients with advanced gastric cancer. Therefore, careful follow-up may be necessary because the prognosis is poor when MUC1 expression is present.

Renal function is associated with prognosis in stent-change therapy for malignant ureteral obstruction

  • Yoon, Ji Hyung;Park, Sejun;Park, Sungchan;Moon, Kyung Hyun;Cheon, Sang Hyeon;Kwon, Taekmin
    • Investigative and Clinical Urology
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    • v.59 no.6
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    • pp.376-382
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    • 2018
  • Purpose: The authors performed this study to investigate the risk factors for predicting stent failure and to evaluate its impact on prognosis. Materials and Methods: Between January 2002 and March 2017, we retrospectively reviewed 117 consecutive patients who underwent retrograde ureteral stenting and exchanging at least once every 3 months for malignant ureteral obstruction. The patients were classified according to their pre-stenting chronic kidney disease (CKD) stage. The factors affecting stent failure were analyzed using a logistic regression model. Overall survival (OS) was estimated, and the prognostic significance of each variable was estimated using Cox proportional-hazards regression modeling. Results: Before stenting, 91 patients were CKD stages 1-3 and 26 patients were CKD stages 4-5. These two groups differed significantly only in pre-stenting estimated glomerular filtration rate (eGFR), bilateral obstruction, and pre-stenting pyuria. Among the 117 patients, stent failure occurred in 30 patients (25.6%), and there were no differences between the groups. Pre-stenting pyuria and post-stenting complications were significant predictors of stent failure. There were 79 deaths in total, including 56 in the CKD stages 1-3 group and 23 in the CKD stages 4-5 group. In the multivariate analysis predicting patient OS, pre-stenting eGFR and post-stenting disease progression were significant factors. Conclusions: Internal ureteral stenting was effective for maintaining renal function in malignant ureteral obstruction. However, it did not restore renal function, which is related to the prognosis of the patients. Therefore, to improve patients' renal function and prognosis, patients who require stenting must be quickly recognized and treated.