• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2055-2060
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• 2016

Background: Colorectal cancer (CRC) is one of the most common causes of death worldwide and in Thailand. The X-ray repair cross-complementary protein 1 (XRCC1) is required for efficient DNA repair. The effects of this gene on survival in colorectal cancer remain controversial and have not been reported in Thailand. The aim of this study was to investigate the association of the XRCC1 gene with survival of colorectal cancer patients in a Thai population. Materials and Methods: Data and blood samples were collected from 255 newly diagnosed and pathologically confirmed CRC patients who were recruited during the period 2002 to 2006 and whose vital status was followed up until 31 October, 2014. Real-time PCR-HRM was used for genotype identification. The Kaplan-Meier method, the log-rank test, and Cox proportional hazard regression were used to estimate cumulative survival curves and compare various survival distributions and adjusted hazard ratios. Results: Most of the cases were males, and the median age was 55 years. The median survival time was 2.43 years. The cumulative 1-, 3-, 5-, 7-, and 10 year survival rates were 76.70%, 39.25%, 26.50%, 16.60% and 3.56%, respectively. After adjustment, female gender, ages 50-59 and ${\geq}60years$, tumour stage III+IV, a signet-ring cell carcinoma, and poor differentiation had significant associations with increased risk of CRC death. While the XRCC1 Arg/Arg homozygote appeared to be a risk factor for CRC death, the association was not significant. Conclusions: The genetic variant in the XRCC1 may not be associated with the survival of CRC patients in Thailand. Further studies are needed to verify our findings.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.59-69
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• 2005

Drought is difficult to detect and monitor, but it is easy to interpret through the drought index. The Palmer Drought Severity Index(PDSI), which is most commonly used as one of drought indices, have been widely used, however, the index have limitation as operational tools and triggers for policy responses. Recently, a new index, the Standardized Precipitation Index(SPI), was developed to improve drought detection and monitoring capabilities. The SPI has an improvement over previous indices md has several characteristics including its simplicity and temporal flexibility that allow its application for water resources on all timescales. Keetch-Byram Dought Index(KBDI) was defined as a number representing the net effect of evapotranspiration and precipitation in producing cumulative moisture deficiency in deep duff or upper soil layer. The purpose of this study is to analyze drought in Korea by using PDSI, SPI and KBDI. The result of this study suggests standard drought index by comparing of estimated drought indices. The data are obtained from Korea Meteorological Administration 56 stations over 30 years in each of the 8 sub-basins covering the whole nation. It is found that the PDSI had the advantage to detect the stage of drought resulting from cumulative shortage of rainfall, while SPI and KBDI had the advantage to detect the stage of drought resulting from short-term shortage of rainfall.

• Safety and Health at Work
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• v.9 no.3
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• pp.290-295
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• 2018

Background: There is little information on the dose-response relationship between exposure to occupational carcinogenic agents and mesothelioma. This study aimed to investigate this association as well as the existence of agents other than asbestos that might cause mesothelioma. Methods: The Swedish component of the Nordic Occupational Cancer (NOCCA) study consists of 6.78 million individuals with detailed information on occupation. Mesothelioma diagnoses recorded in 1961-2009 were identified through linkage to the Swedish Cancer Registry. We determined cumulative exposure, time of first exposure, and maximum exposure intensity by linking data on occupation to the Swedish NOCCA job-exposure matrix, which includes 29 carcinogenic agents and corresponding exposure for 283 occupations. To assess the risk of mesothelioma, we used conditional logistic regression models to estimate hazard ratios and 95% confidence intervals. Results: 2,757 mesothelioma cases were identified in males, including 1,416 who were exposed to asbestos. Univariate analyses showed not only a significant excess risk for maximum exposure intensity, with a hazard ratio of 4.81 at exposure levels 1.25-2.0 fb/ml but also a clear dose-response effect for cumulative exposure with a 30-, 40-, and 50-year latency time. No convincing excess risk was revealed for any of the other carcinogenic agents included in the Swedish NOCCA job-exposure matrix. Conclusion: When considering asbestos exposure, past exposure, even for short periods, might be enough to cause mesothelioma of the pleura later in life.

• Tuberculosis and Respiratory Diseases
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• v.82 no.4
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• pp.341-347
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• 2019

Background: Information about the epidemiology of venous thromboembolism (VTE) recurrence in Korea is lacking. The purpose of this study was to investigate VTE cumulative recurrence rates and identify risk factors for VTE recurrence among Korean adults. Methods: A retrospective cohort study was conducted on adult patients (${\geq}18years$) admitted to a university teaching hospital for pulmonary embolism (PE) from 2005 to 2013. The main outcome of interest was a recurrence of VTE. We used Cox proportional hazard regression analyses to calculate the relative risk of VTE recurrence. Results: Five-year cumulative incidence of recurrent VTE events was 21.5% (95% confidence interval [CI], 17.7-25.4) in all cases of PE; 17% after provoked and 27% after unprovoked PE. Multivariate analysis showed that body mass index (BMI) of ${\geq}25$ (hazard ratio [HR], 2.02; 95% CI, 1.17-3.46; p=0.01) and longer anticoagulation therapy duration (HR, 0.90; 95% CI, 0.84-0.96; p<0.01) were independently associated with risk of VTE recurrence. Risk factors not found to be statistically significant at the <0.05 level included history of VTE (HR, 1.81; 95% CI, 0.84-3.88; p=0.12), unprovoked PE (HR, 1.70; 95% CI, 0.89-3.25; p=0.10), symptomatic deep vein thrombosis (HR, 1.62; 95% CI, 0.89-2.94; p=0.10), and female sex (HR, 1.42; 95% CI, 0.78-2.55; p=0.24). We found that age, history of cancer, and other co-morbidities did not significantly affect the risk of VTE recurrence. Conclusion: Recurrence of VTE after PE is high. Patients with BMI ${\geq}25$ or reduced anticoagulation therapy duration have a higher risk of recurrent VTE.

• Journal of Chest Surgery
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• v.54 no.1
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• pp.36-44
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• 2021

Background: Extracorporeal membrane oxygenation (ECMO) has become increasingly accepted as a life-saving procedure for patients with severe acute respiratory distress syndrome (ARDS). This study investigated the relationship between cumulative fluid balance (CFB) and outcomes in adult ARDS patients treated with ECMO. Methods: We retrospectively analyzed the data of adult ARDS patients who received ECMO between December 2009 and December 2019 at Korea University Anam Hospital. CFB was calculated during the first 7 days after ECMO initiation. The primary endpoint was 28-day mortality. Results: The 74 patients were divided into survivor (n=33) and non-survivor (n=41) groups based on 28-day survival. Non-survivors showed a significantly higher CFB at 1-7 days (p<0.05). Cox multivariable proportional hazard regression revealed a relationship between CFB on day 3 and 28-day mortality (hazard ratio, 3.366; 95% confidence interval, 1.528-7.417; p=0.003). Conclusion: In adult ARDS patients treated with ECMO, a higher positive CFB on day 3 was associated with increased 28-day mortality. Based on our findings, we suggest a restrictive fluid strategy in ARDS patients treated with ECMO. CFB may be a useful predictor of survival in ARDS patients treated with ECMO.

• Korean Journal of Social Welfare
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• v.59 no.1
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• pp.301-327
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• 2007

The purpose of this study is to examine the timing and the risk factors associated with the adoption of legally-free foster children. The sample of the study was drawn from foster care files of Adoption and Foster Care Analysis and Reporting System(AFCARS) in 32 states between October 1998 (FY 1999) and September 2002(FY 2002). The timing post-TPR to adoption was examined by plotting the Kaplan-Meier cumulative hazard function for adoption and by plotting the KM hazard functions stratified by child's race and child's age at TPR. Cox proportional-hazards regression analysis was used to identify risk factors for adoption of legally-free foster children after TPR. The hazard of adoption was very low immediately after TPR but increased steadily starting at 3 months and then declined after 20 months. The cumulative hazard functions for White non-Hispanic children and Black non-Hispanic children crossed over at 13 months after TPR. Racial minority status, older age, and disability were negatively associated with the hazard of adoption. Physical abuse, sexual abuse had the lower hazard for adoption compared by neglect. Caretaker's inability to cope had the slightly lower hazard for adoption whereas inadequate housing showed the slightly greater hazard for adoption. Characteristics of foster care services turned into be powerful predictors of adoption. Specifically, legally-free children placed in pre-adoptive homes, those who shared the same racial/ethnic background with their foster caretakers, and those who were placed in two-parent families have a greater likelihood of adoption. The findings highlight the importance of foster care service provisions after TPR to facilitate adoption of legally-free foster children. Furthermore, a more substantial resources and targeted support for foster children who experience physical abuse and sexual abuse in need of adoption should be provided for moving the foster children into permanency.

• Journal of Korean Neurosurgical Society
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• v.65 no.3
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• pp.469-478
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• 2022

Objective : Cranial base chordomas are rare, but their treatment is challenging. Tumor recurrence is still common despite improvements in microsurgical techniques and postoperative radiotherapy. We retrospectively analyzed the course of treatment, overall survival, and recurrence/progression of chordomas over the past 10 years. Methods : We retrospectively reviewed 50 patients who underwent surgery at Tianjin Huanhu Hospital between 2010 and 2020 and were pathologically diagnosed with chordomas. Tumor resection was performed within the maximum safe range in all patients; the extent of resection was evaluated by imaging; and the incidence of complications, recurrence or progression, and overall survival were assessed. Results : Fifty patients were divided into the low-risk group (LRG) and high-risk group (HRG) based on the cranial chordoma grading system (CCGS). The Karnofsky Performance Scale scores and gross total resection rate of the LRG were significantly higher than those of the HRG (p<0.05). The incidence of complications and mortality in the LRG were lower than those of HRG. The analysis of cumulative survival and cumulative recurrence free survival/progression free survival (RFS/PFS) showed no statistical differences in the extent of resection for survival, recurrence, or progression. Univariate and multivariate analyses showed that Ki-67 was significantly associated with tumor recurrence and was an independent hazard factor (p=0.02). Conclusion : The CCGS can help neurosurgeons anticipate surgical outcomes. Pathological results are important in evaluating the possibility of tumor recurrence, and postoperative radiotherapy improves overall survival and RFS/PFS.

• The Korean Journal of Applied Statistics
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• v.29 no.7
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• pp.1231-1246
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• 2016

Cause-specific hazard model (Prentice et al., 1978) and subdistribution hazard model (Fine and Gray, 1999) are mostly used for the right censored survival data with competing risks. Some other models for survival data with competing risks have been subsequently introduced; however, those models have not been popularly used because the models cannot provide reliable statistical estimation methods or those are overly difficult to compute. We introduce simple and reliable competing risk regression models which have been recently proposed as well as compare their methodologies. We show how to use SAS and R for the data with competing risks. In addition, we analyze survival data with two competing risks using five different models.

• Journal of Korean Critical Care Nursing
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• v.3 no.2
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• pp.1-11
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• 2010

Purpose: This study was designed to identify the factors affecting healing of Stage 2 pressure ulcer in an acute care facility in Korea. Methods: 286 Stage 2 pressure ulcers of 145 patients were examined. Data were collected in the period between October $1^{st}$, 2006 and September $30^{th}$, 2007. Data were analyzed with Kaplan-Meier survival analysis for cumulative recovery rate of Stage 2 pressure ulcers. Cox proportional hazard model was used to examine effects of multiple variables simultaneously. Results: Out of 286 initial Stage 2 pressure ulcers, 204 (71.3%) pressure ulcers healed completely. The median time to heal was 15 days according to Kaplan-Meier survival analysis. Cox proportional hazard model showed that the Stage 2 pressure ulcers healed more quickly when pressure redistribution surfaces were used (p<.001, HR=2.184), patients were administered with vitamins (p= .038, HR=1.451), and the size of the pressure ulcers were small (${\leq}3.0cm^2$, p= .006, HR=1.765). Conclusion: The factors contributing to the healing of Stage 2 pressure ulcer in an acute care setting were the application of pressure redistribution surface, small ulcer size (${\leq}3.0cm^2$), and the administration of vitamins.

• Environmental Engineering Research
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• v.24 no.1
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• pp.150-158
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• 2019

Soil contaminated with heavy metals from artisanal gold mining in Anka Local Government Area in Northwestern Nigeria was investigated to evaluate the human health risk as a result of heavy metals. Measured concentration of heavy metals and exposure parameters were used to estimate human carcinogenic and non-carcinogenic risk. GIS-based Kriging method was utilized to create a prediction maps of human health risks and probability maps of heavy metals concentrations exceeding their threshold limits. Hazard index calculation showed that 21 out of 23 locations are posing non-cancer risk for children. Adults and children are at high cancer risk in all locations as the total cancer risk exceeded $1{\times}10^{-6}$ (the lower limit CTR value). Kriging model showed that only a very small area in Anka has a hazard index of less than unity and cumulative target risk of less than $1{\times}10^{-4}$, indicating a significant carcinogenic and non-carcinogenic risks for children. The probability of heavy metals to exceed their threshold concentrations around the study area was also found to be high.