• 제목/요약/키워드: survival curves

검색결과 147건 처리시간 0.032초

출혈성 쇼크를 일으킨 흰쥐에서 로지스틱 회귀분석을 이용한 생존율 예측 (A survival prediction model of hemorrhagic shock in rats using a logistic regression equation)

  • 이탁형;이주형;정상원;김덕원
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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    • pp.132-134
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    • 2009
  • Hemorrhagic shock is a common cause of death in emergency rooms. Since the symptoms of hemorrhagic shock occur after shock has considerably progressed, it is difficult to diagnose shock early. The purpose of this study was to improve early diagnosis of hemorrhagic shock using a survival prediction model in rats. We measured ECG, blood pressure, respiration and temperature in 45 Sprague-Dawley rats, and then obtained a logistic regression equation predicting survival rates. Area under the ROC curves was 0.99. The Hosmer-Lemeshow goodness-of-fit chi-square was 0.86(degree of freedom=8, p=0.999). Applying the determined optimal boundary value of 0.25, the accuracy of survival prediction was 94.7%

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Random Permutation Test for Comparison of Two Survival Curves

  • Kim, Mi-Kyung;Lee, Jae-Won;Lee, Myung-Hoe
    • Communications for Statistical Applications and Methods
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    • 제8권1호
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    • pp.137-145
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    • 2001
  • There are many situations in which the well-known tests such as log-rank test and Gehan-Wilcoxon test fail to detect the survival differences. Assuming large samples, these tests are developed asymptotically normal properties. Thus, they shall be called asymptotic tests in this paper, Several asymptotic tests sensitive to some specific types of survival differences have been recently proposed. This paper compares by simulations the test levels and the powers of the conventional asymptotic tests and their random permutation versions. Simulation studies show that the random permutation tests possess competitive powers compared to the corresponding asymptotic tests, keeping exact test levels even in the small sample case. It also provides the guidelines for choosing the valid and most powerful test under the given situation.

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Survival analysis of spinal muscular atrophy type I

  • Park, Hyun-Bin;Lee, Soon-Min;Lee, Jin-Sung;Park, Min-Soo;Park, Kook-In;NamGung, Ran;Lee, Chul
    • Clinical and Experimental Pediatrics
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    • 제53권11호
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    • pp.965-970
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    • 2010
  • Purpose: The life expectancy of patients with spinal muscular atrophy (SMA) type I is generally considered to be less than 2 years. Recently, with the introduction of proactive treatments, a longer survival and an improved survival rate have been reported. In this study, we analyzed the natural courses and survival statistics of SMA type I patients and compared the clinical characteristics of the patients based on their survival periods. Methods: We reviewed the medical records of 14 pediatric patients diagnosed with SMA type I during a 9-year period. We examined the demographic and clinical characteristics of these patients, calculated their survival probabilities, and plotted survival curves as on the censoring date, January 1, 2010. We also compared the characteristics of the patients who died before the age of 24 months (early-death, ED group) and those who survived for 24 months or longer (long-survival, LS group). Results: The mean survival time was $22.8{\pm}2.0$ months. The survival probabilities at 6 months, 12 months, 18 months, 24 months, and 30 months were 92.9%, 92.9%, 76.0%, 76.0%, and 65.1%, respectively. Birth weight was the only factor that showed a statistically significant difference between the ED and LS groups ($P$=0.048). Conclusion: In this study, the survival probabilities at 2 years were far greater than expected. Because of the limited number of patients and information in this study, the contribution of improved supportive care on longer survival could not be clarified; this may be elucidated in larger cohort studies.

Effect of Screening on Variation in Cervical Cancer Survival by Socioeconomic Determinants - a Study from Rural South India

  • Thulaseedharan, Jissa Vinoda;Malila, Nea;Swaminathan, Rajaraman;Esmy, Pulikottil Okuru;Cherian, Mary;Hakama, Matti;Muwonge, Richard;Sankaranarayanan, Rengaswamy
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권13호
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    • pp.5237-5242
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    • 2015
  • Background: Socioeconomic factors are associated with screening in terms of reducing the risk of cervical cancer. This study aimed to clearly establish the effect of screening on variation in socio-economic factor-specific survival estimates. Materials and Methods: Survival estimates were calculated using the life table method for 165 women from the routine care control arm and 67 from the visual inspection with acetic acid screening arm diagnosed with cervical cancer during 2000-2006 in rural south India. Kaplan-Meier survival curves were plotted to compare the variation in survival by socioeconomic factors. Results: Whereas there was a significant variation in survival estimates of the different categories of age at diagnosis among the screen-detected cancers with women aged<50 years having an improved survival, no significant variation was noted among women diagnosed with cervical cancer from the control arm. Compared to the variation among the cancer cases detected in the unscreened control group, screening widened the variation in survival estimates by age and type of house, and reduced the variation by education. The direction of the magnitude of the survival estimates was reversed within the different categories of occupation, marital status and household income in the screen-detected cancer cases compared to control group cancer cases. Also, women diagnosed with stage 1 disease had a very good survival. Conclusions: Screening changed the pattern of survival by socio-economic factors. We found improved survival rates in screened women aged <50 years, with no formal education, manual workers and married women.

Providing Reliable Prognosis to Patients with Gastric Cancer in the Era of Neoadjuvant Therapies: Comparison of AJCC Staging Schemata

  • Kim, Gina;Friedmann, Patricia;Solsky, Ian;Muscarella, Peter;McAuliffe, John;In, Haejin
    • Journal of Gastric Cancer
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    • 제20권4호
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    • pp.385-394
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    • 2020
  • Purpose: Patients with gastric cancer who receive neoadjuvant therapy are staged before treatment (cStage) and after treatment (ypStage). We aimed to compare the prognostic reliability of cStage and ypStage, alone and in combination. Materials and Methods: Data for all patients who received neoadjuvant therapy followed by surgery for gastric adenocarcinoma from 2004 to 2015 were extracted from the National Cancer Database. Kaplan-Meier (KM)curves were used to model overall survival based on cStage alone, ypStage alone, cStage stratified by ypStage, and ypStage stratified by cStage. P-values were generated to summarize the differences in KM curves. The discriminatory power of survival prediction was examined using Harrell's C-statistics. Results: We included 8,977 patients in the analysis. As expected, increasing cStage and ypStage were associated with worse survival. The discriminatory prognostic power provided by cStage was poor (C-statistic 0.548), while that provided by ypStage was moderate (C-statistic 0.634). Within each cStage, the addition of ypStage information significantly altered the prognosis (P<0.0001 within cStages I-IV). However, for each ypStage, the addition of cStage information generally did not alter the prognosis (P=0.2874, 0.027, 0.061, 0.049, and 0.007 within ypStages 0-IV, respectively). The discriminatory prognostic power provided by the combination of cStage and ypStage was similar to that of ypStage alone (C-statistic 0.636 vs. 0.634). Conclusions: The cStage is unreliable for prognosis, and ypStage is moderately reliable. Combining cStage and ypStage does not improve the discriminatory prognostic power provided by ypStage alone. A ypStage-based prognosis is minimally affected by the initial cStage.

Conservative Neck Dissection in Oral Cancer Patients: a 5 Year Retrospective Study in Malaysia

  • Balasundram, Sathesh;Mustafa, Wan Mahadzir Wan;Ip, Jolene;Adnan, Tassha Hilda;Supramaniam, Premaa
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권8호
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    • pp.4045-4050
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    • 2012
  • Objective: The impact of ablative oral cancer surgery was studied, with particular reference to recurrence and nodal metastasis, to assess survival probability and prognostic indicators and to elucidate if ethnicity influences the survival of patients. Methods: Patients who underwent major ablative surgery of the head and neck region with neck dissection were identified and clinical records were assessed. Inclusion criteria were stage I-IV oral and oropharyngeal malignancies necessitating resection with or without radiotherapy from 2004 to 2009. All individuals had a pre-operative assessment prior to the surgery. The post operative assessment period ranged from 1 year to 5 years. Survival distributions were analyzed using Kaplan-Meier curves. Results: 87 patients (males:38%; females:62%) were included in this study, with an age range of 21-85 years. Some 78% underwent neck dissections while 63% had surgery and radiotherapy. Nodal recurrence was detected in 5.7% while 20.5% had primary site recurrence within the study period. Kaplan-Meier survival analysis revealed that the median survival time was 57 months. One year overall survival (OS) rate was 72.7% and three year overall survival rate dropped to 61.5%. On OS analysis, the log-rank test showed a significant difference of survival between Malay and Chinese patients (Bonferroni correction p=0.033). Recurrence-free survival (RFS) analysis revealed that 25% of the patients have reached the event of recurrence at 46 months. One year RFS rate was 85.2% and the three year survival rate was 76.1%. In the RFS analysis, the log-rank test showed a significant difference in the event of recurrence and nodal metastasis (p<0.001). Conclusion: Conservative neck is effective, in conjunction with postoperative radiotherapy, for control of neck metastases. Ethnicity appears to influence the survival of the patients, but a prospective trial is required to validate this.

Survival Analysis and Prognostic Factors for Colorectal Cancer Patients in Malaysia

  • Hassan, Muhammad Radzi Abu;Suan, Mohd Azri Mohd;Soelar, Shahrul Aiman;Mohammed, Noor Syahireen;Ismail, Ibtisam;Ahmad, Faizah
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권7호
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    • pp.3575-3581
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    • 2016
  • Background: Cancer survival analysis is an essential indicator for effective early detection and improvements in cancer treatment. This study was undertaken to document colorectal cancer survival and associated prognostic factors in Malaysians. Materials and Methods: All data were retrieved from the National Cancer Patient Registry-Colorectal Cancer. Only cases with confirmed diagnosis through histology between the year 2008 and 2009 were included. Retrieved data include socio-demographic information, pathological features and treatment received. Survival curves were plotted using the Kaplan-Meier method. Univariate analysis of all variables was then made using the Log-rank test. All significant factors that influenced survival of patients were further analysed in a multivariate analysis using Cox' regression. Results: Total of 1,214 patients were included in the study. The overall 3- and 5-year survival rates were 59.1% and 48.7%, respectively. Patients with localized tumours had better prognosis compared to those with advanced stage cancer. In univariate analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p=0.001) were found to be predictors of survival. None of the socio-demographic characteristics were found to exert any influence. In Cox regression analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p<0.001) were determined as independent prognostic factors of survival after adjusted for age, gender and ethnicity. Conclusions: The overall survival rate for colorectal cancer patients in Malaysia is similar to those in other Asian countries, with staging at diagnosis, primary tumor size, involvement of lymph node and treatment modalities having significant effects. More efforts are needed to improve national survival rates in future.

Influence of Ethnicity on Survival of Breast Cancer Patients in Turkey

  • Kuzhan, Abdurahman;Adli, Mustafa;Buyukhatipoglu, Hakan
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권21호
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    • pp.9199-9202
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    • 2014
  • Background: Kurdish women with breast cancer have more unfavorable prognostic factors than their Turkish and Arab counterparts. However, the effects of these factors on breast cancer survival among these ethnic groups remain unclear. We therefore investigated the impact of ethnicity on survival in breast cancer patients in Turkey. Materials and Methods: Ethnicity, age, stage at diagnosis, tumor characteristics, treatments given (surgery, chemotherapy, radiotherapy and hormone therapy), and survival times were recorded. Kaplan-Meier analysis was used to estimate the overall survival times and survival plots. Log-rank test was used to compare the survival curves.Results: Of the 723 breast cancer patients included in the study, 496 (68.7%) were Turkish, 189 (26.2%) were Kurdish, 37 (5.1%) were Arabic and 1 was Armenian. Kurdish women with breast cancer had larger tumor sizes and higher rates of hormone receptor negative tumors than Turkish and Arab patients. Mean follow-up time was 118.4 [95% Confidence Interval (CI): 95.4-141.3] months, and it was 129.9 (95% CI: 93.7-166.2), 124.2 (95% CI: 108.4-140.1) and 103.1 (95% CI: 85.9-120.4) months for Turkish, Arabic and Kurdish patients, respectively. Conclusions: Kurdish ethnicity is associated with higher rates of hormone receptor negative and triple-negative tumors and with worse survival. Clinical and epidemiological research is warranted to elucidate reasons underlying overall survival, variations in tumor biology, differences in treatment responsiveness, and effects of social factors among ethnic groups in Turkey.

Metachronous Ovarian Metastases Following Resection of the Primary Gastric Cancer

  • Jun, Si-Youl;Park, Jong-Kwon
    • Journal of Gastric Cancer
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    • 제11권1호
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    • pp.31-37
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    • 2011
  • Purpose: We performed this study to evaluate the clinical presentation as well as the proper surgical intervention for ovarian metastasis from gastric cancers and these tumors were identified during postoperative follow-up. This will help establish the optimal strategy for improving the survival of patients with this entity. Materials and Methods: 22 patients (3.2%) with ovarian metastasis were noted when performing a retrospective chart review of (693) females patients who had undergone a resection for gastric cancer between 1981 and 2008. The covariates used for the survival analysis were the patient age at the time of ovarian relapse, the size of the tumor, the initial TNM stage of the gastric cancer, the interval to metastasis and the presence of gross residual disease after treatment for Krukenberg tumor. The cumulative survival curves for the patient groups were calculated with the Kaplan-Meier method and they were compared by means of the Log-Rank test. Results: The average age of the patients was 48.6 years (range: 24 to 78 years) and the average survival time of the 22 patients was 18.8 months (the estimated 3-year survival rate was 15.8%) with a range of 2 to 59 months after the diagnosis of Krukenberg tumor. The survival rate for patients without gross residual disease was longer than that of the patients with gross residual disease (P=0.0003). In contrast, patient age, the size of ovarian tumor, the initial stage of gastric adenocarcinoma, the interval to metastasis and adjuvant chemotherapy were not prognostic indicators for survival after the development of ovarian metastasis. Conclusions: Early diagnosis and complete resection are the only possible hope to improve survival. As the 3-year survival rate after resection of Krukenberg tumor is 15.8%, it seems worthwhile to consider performing tumorectomy as the second cytoreduction.

Using SEER Data to Quantify Effects of Low Income Neighborhoods on Cause Specific Survival of Skin Melanoma

  • Cheung, Min Rex
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권5호
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    • pp.3219-3221
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    • 2013
  • Background: This study used receiver operating characteristic (ROC) curves to screen Surveillance, Epidemiology and End Results (SEER) skin melanoma data to identify and quantify the effects of socioeconomic factors on cause specific survival. Methods: 'SEER cause-specific death classification' used as the outcome variable. The area under the ROC curve was to select best pretreatment predictors for further multivariate analysis with socioeconomic factors. Race and other socioeconomic factors including rural-urban residence, county level % college graduate and county level family income were used as predictors. Univariate and multivariate analyses were performed to identify and quantify the independent socioeconomic predictors. Results: This study included 49,999 parients. The mean follow up time (SD) was 59.4 (17.1) months. SEER staging (ROC area of 0.08) was the most predictive foctor. Race, lower county family income, rural residence, and lower county education attainment were significant univariates, but rural residence was not significant under multivariate analysis. Living in poor neighborhoods was associated with a 2-4% disadvantage in actuarial cause specific survival. Conclusions: Racial and socioeconomic factors have a significant impact on the survival of melanoma patients. This generates the hypothesis that ensuring access to cancer care may eliminate these outcome disparities.