• Asian Pacific Journal of Cancer Prevention
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• 제14권9호
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• pp.5111-5116
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• 2013

Background: Early in the 21st century, cancers are the second cause of death worldwide. Colon cancer is third most common cancer and one of the few amenable to early diagnosis and treatment. Evaluation of factors affecting this cancer is important to increase survival time. Some of these factors affecting all diseases including cancer are social determinants of health. According to the importance of this disease and relation with these factors, this study was conducted to assess the relationship between social determinants of health and colon cancer survival. Materials and Methods: This was a cross-sectional, descriptive study for patients with colon cancer registered in the Cancer Research Center of Shahid Beheshti University of Medical Science, from April 2005 to November 2006, performed using questionnaires filled by telephone interview with patients (if patients had died, with family members). Data was analyzed with SPSS software (version 19) for descriptive analysis and STATA software for survival analysis including log rank test and three step Cox Proportional Hazard regression. Results: Five hundred fifty nine patients with ages ranging from 23 to 88 years with mean${\pm}$standard deviation of $63{\pm}11.8$ years were included in the study. The five year survival was 68.3%( 387 patients were alive and 172 patients were dead by the end of the study). The Cox proportional hazard regression showed 5-year survival was related to age (HR=0.53, p=0.042 for>50 years versus<50 years old) in first step, gender (HR=0.60, p=0.006 for female versus male) in second step, job (HR=1.7, p=0.001 for manual versus non manual jobs), region of residency (HR=3.49, p=0.018 for west versus south regions), parents in childhood (HR=2.87, p=0.012 for having both parents versus not having), anatomical cancer location (HR=2.16, p<0.033 for colon versus rectal cancer) and complete treatment (HR=5.96, p<0.001 for incomplete versus complete treatment). Conclusions: Social determinants of health such as job, city region residency and having parents during childhood have significant effects in 5-year survival of colon cancer and it may be better to consider these factors in addition to developing cancer treatment and to focus on these determinants of health in long-time planning.

• 한국콘텐츠학회논문지
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• 제12권2호
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• pp.255-264
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• 2012

본 연구는 문화콘텐츠산업 소속기업들의 생존율이 어떠한 지를 파악하기 위해 생존분석을 이용하였다. 즉, 전체 기업의 생존율과 위험률을 추정하였고, 관심 있는 특성별로 생존기간 차이분석을 수행하였다. 이러한 분석들을 통해 다음과 같은 결과가 도출되었다: 첫째, 연구기간에 설정된 문화콘텐츠산업의 중소기업들 평균 생존율은 74개월이고, 중위수 생존율은 72개월로 추정되었다. 둘째, 세부업종별로 유의한 차이가 있었다. 즉, 방송산업, 엔터테인먼트산업, 인쇄출판업의 생존기간이 광고 및 정보제공업과 기타 제조제품업의 생존기간보다 큰 것으로 나타났다. 셋째, 본사 소재지별로 차이가 있으며, 영남권의 생존기간이 가장 큰 것으로 분석되었다. 넷째, 종업원 규모별로 유의하였으나, 생존기간의 패턴이 U-형태로 생존기간이 감소하다가 증가하는 형태로 나타났다. 마지막으로, 재무등급과 동업종 종사업력 둘 다 커질수록 생존기간이 증가하였다. 이외의 특성들은 유의하지 않았다. 본 연구의 기여는 아직까지 적용되지 않았던 문화콘텐츠산업에 생존분석 방법을 적용한 것이고 이것을 기반으로 문화콘텐츠산업의 다양한 분야에 생존분석을 적용할 수 있는 방법을 소개하였다는 점이다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3465-3470
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• 2014

Background: Previous studies have generated conflicting evidence regarding associations between family history and survival after gastric cancer surgery. In this study, we investigated this question using a meta-analysis. Materials and Methods: To identify relevant studies, PubMed and Embase databases were searched up to June 2013. Two reviewers independently assessed search results and data extraction of included studies. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) were calculated based on fixed- or random-effects models. Homogeneity of effects across studies was assessed using $x^2$ test statistics and quantified by $I^2$. Results: A total of five studies were selected according to the inclusion criteria. The total number of patients included was 2,030, which ranged from 145 to 598 per study. There was no significant difference in OS by family history of cancer (HR=0.83, 95%CIs=0.50-1.38), but subgroup analysis of patients with a first-degree family history of cancer (HR=0.74, 95%CIs=0.60-0.93) and gastric cancer family history (HR=0.56, 95%CIs=0.41-0.76) tended to show better OS in these patients. Conclusions: This meta-analysis suggests that a first-degree family history of cancer or gastric cancer family history is associated with better survival of gastric cancer patients after surgery, after a systematic review of five previous studies. These results can be applied by clinicians when counselling patients regarding their risk of death from gastric cancer. Further study is needed to investigate the underlying mechanism between family history and survival in gastric cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.791-794
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• 2012

A retrospective cohort study was carried out with 340 female breast cancer at a teaching university in northeast of Thailand recruited and followed-up until the end of 2006. Survival probabilities were estimated using the Kaplan-Meier method. 161 cases were alive after five years and 58 patients were lost to follow-up. The overall observed survival rates at 1, 3 and 5 years were 83.3%, 59.9% and 42.9%, respectively. When analysis was conducted for stage combined into 2 groups, early (stage I, II and unknown) and late (stage III and IV), the 5-year survival rate for early stage (60%; 95%CI: 0.51-0.67), was higher than for late stage (27%; 95%CI: 0.19-0.34) with high statistical significance (p<0.001). The hazard ratio of patients with stage IV was 11.6 times greater than for stage I (p=0.03). The findings indicate that the different stages of breast cancer markedly effect the overall survival rate.

• Korean Journal of Ophthalmology
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• 제32권6호
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• pp.470-477
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• 2018

Purpose: To investigate the relationship between the progression of visual field (VF) loss and changes in lamina cribrosa depth (LCD) as determined by spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging in patients with primary open angle glaucoma (POAG). Methods: Data from 60 POAG patients (mean follow-up, $3.5{\pm}0.7$ years) were included in this retrospective study. The LCD was measured in the optic disc image using SD-OCT enhanced depth imaging scanning at each visit. Change in the LCD was considered to either 'increase' or 'decrease' when the differences between baseline and the latest two consecutive follow-up visits were greater than the corresponding reproducibility coefficient value ($23.08{\mu}m$, as determined in a preliminary reproducibility study). All participants were divided into three groups: increased LCD (ILCD), decreased LCD (DLCD), and no LCD change (NLCD). The Early Manifest Glaucoma Trial criteria were used to define VF deterioration. Kaplan-Meier survival analysis and Cox's proportional hazard models were performed to explore the relationship between VF progression and LCD change. Results: Of the 60 eyes examined, 35.0% (21 eyes), 28.3% (17 eyes), and 36.7% (22 eyes) were classified as the ILCD, DLCD, and NLCD groups, respectively. Kaplan-Meier survival analysis showed a greater cumulative probability of VF progression in the ILCD group than in the NLCD (p < 0.001) or DLCD groups (p = 0.018). Increased LCD was identified as the only risk factor for VF progression in the Cox proportional hazard models (hazard ratio, 1.008; 95% confidence interval, 1.000 to 1.015; p = 0.047). Conclusions: Increased LCD was associated with a greater possibility of VF progression. The quantitative measurement of LCD changes, determined by SD-OCT, is a potential biomarker for the prediction of VF deterioration in patients with POAG.

• 노동경제논집
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• 제43권2호
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• pp.41-74
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• 2020

본 연구는 한국고용정보원의 청년패널조사 직업력자료(1~12차 : 2007~2018년)를 이용하여 임금근로자의 첫 일자리 취업 특성과 지속기간 분포를 살펴보고, 첫 일자리 이탈 영향요인을 생존분석(survival analysis)을 활용하여 추정하였다. 분석 결과, 다른 조건이 일정한 상태에서 상용직 근로자의 이탈 가능성이 임시/일용직 근로자에 비해 낮고, 전공일치도가 높은 집단은 전공불일치 집단보다 이탈 가능성이 매우 낮은 것으로 나타났다. 그리고 소득수준이 높을수록 이탈 가능성은 매우 낮은 것으로 나타나, 저소득 취업자의 이탈 가능성이 매우 큼을 반증하고 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7133-7136
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• 2013

Background: We studied Surveillance, Epidemiology and End Results (SEER) breast cancer data of Georgia USA to analyze the impact of socio-economic factors on the disparity of breast cancer treatment outcome. Materials and Methods: This study explored socio-economic, staging and treatment factors that were available in the SEER database for breast cancer from Georgia registry diagnosed in 2004-2009. An area under the receiver operating characteristic curve (ROC) was computed for each predictor to measure its discriminatory power. The best biological predictors were selected to be analyzed with socio-economic factors. Survival analysis, Kolmogorov-Smirnov 2-sample tests and Cox proportional hazard modeling were used for univariate and multivariate analyses of time to breast cancer specific survival data. Results: There were 34,671 patients included in this study, 99.3% being females with breast cancer. This study identified race and education attainment of county of residence as predictors of poor outcome. On multivariate analysis, these socio-economic factors remained independently prognostic. Overall, race and education status of the place of residence predicted up to 10% decrease in cause specific survival at 5 years. Conclusions: Socio-economic factors are important determinants of breast cancer outcome and ensuring access to breast cancer treatment may eliminate disparities.

• Asian Pacific Journal of Cancer Prevention
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• 제15권12호
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• pp.4839-4842
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• 2014

Background: Although the Cox's proportional hazard model is the popular approach for survival analysis to investigate significant risk factors of cancer patient survival, it is not appropriate in the case of log-term disease free survival. Recently, cure rate models have been introduced to distinguish between clinical determinants of cure and variables associated with the time to event of interest. The aim of this study was to use a cure rate model to determine the clinical associated factors for cure rates of patients with breast cancer (BC). Materials and Methods: This prospective cohort study covered 305 patients with BC, admitted at Shahid Faiazbakhsh Hospital, Tehran, during 2006 to 2008 and followed until April 2012. Cases of patient death were confirmed by telephone contact. For data analysis, a non-mixed cure rate model with Poisson distribution and negative binomial distribution were employed. All analyses were carried out using a developed Macro in WinBugs. Deviance information criteria (DIC) were employed to find the best model. Results: The overall 1-year, 3-year and 5-year relative survival rates were 97%, 89% and 74%. Metastasis and stage of BC were the significant factors, but age was significant only in negative binomial model. The DIC also showed that the negative binomial model had a better fit. Conclusions: This study indicated that, metastasis and stage of BC were identified as the clinical criteria for cure rates. There are limited studies on BC survival which employed these cure rate models to identify the clinical factors associated with cure. These models are better than Cox, in the case of long-term survival.

• 보건행정학회지
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• 제31권1호
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• pp.91-99
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• 2021

Background: The Korean government introduced National Cancer Control Program and strengthening national health insurance coverage for cancer patients. Although many positive effects have been observed, there are also many concerns about cancer management such as patient concentration or time-to-treatment. Thus, we investigated the association between the time-to-treatment and survival of cancer patients, and compared regional differences by time trend. Methods: The data used in this study were national health insurance claims data that included patients diagnosed with lung cancer and received surgical treatment between 2005 and 2015. We conducted survival analysis with Cox proportional hazard model for the association between time-to-treatment and survival in lung cancer. Additionally, we compared the regional differences for time-to-treatment by time trend. Results: A total of 842 lung cancer patients were included, and 52.3% of lung cancer patients received surgical treatment within 30 days. Patients who received surgical treatment after 31 days had higher 5-year or 1-year mortality compared to treatment within 30 days (5-year: hazard ratio [HR], 1.566; 1-year: HR, 1.555; p<0.05). There were some regional differences for time-to-treatment, but it was generally reduced after 2010. Conclusion: Delayed surgical treatment after diagnosis can negatively affect patient outcomes in cancer treatment. To improve cancer control strategies, there are needed to analyze the healthcare delivery system for cancer care considering the severity and types of cancer.

• Communications for Statistical Applications and Methods
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• 제25권2호
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• pp.159-172
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• 2018

In many epidemiological studies, missing values in the outcome arise due to censoring. Such censoring is what makes survival analysis special and differentiated from other analytical methods. There are many methods that deal with censored data in survival analysis. However, few studies have dealt with missing covariates in survival data. Furthermore, studies dealing with missing covariates are rare when data are clustered. In this paper, we conducted a simulation study to compare results of several missing data methods when data had clustered multi-structured type with missing covariates. In this study, we modeled unknown baseline hazard and frailty with Bayesian B-Spline to obtain more smooth and accurate estimates. We also used prior information to achieve more accurate results. We assumed the missing mechanism as MAR. We compared the performance of five different missing data techniques and compared these results through simulation studies. We also presented results from a Multi-Center study of Korean IBD patients with Crohn's disease(Lee et al., Journal of the Korean Society of Coloproctology, 28, 188-194, 2012).