Mechanistic study and analysis of Cox regression model for colon cancer based on SEER database

2021 ◽  
Author(s):  
Xudong Zhou ◽  
Qiwen Liu
Keyword(s):  
Colon Cancer ◽  
Regression Model ◽  
Cox Regression ◽  
Mechanistic Study ◽  
Seer Database ◽  
Cox Regression Model

scholarly journals The main contributor to the upswing of survival in locally advanced colorectal cancer: an analysis of the SEER database

2019 ◽  
Vol 12 ◽  
pp. 175628481986215 ◽  
Author(s):  
Yuqiang Li ◽  
Lilan Zhao ◽  
Cenap Güngör ◽  
Fengbo Tan ◽  
Zhongyi Zhou ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Regression Model ◽  
Advanced Colorectal Cancer ◽  
Cox Regression ◽  
Locally Advanced ◽  
Seer Database ◽  
Cox Regression Model ◽  
Main Contributor ◽  
Locally Advanced Colorectal Cancer

Background: There is no conclusion about the most important contributor to the upswing of locally advanced colorectal cancer (LACRC) survival. Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) database was extracted to identify colorectal adenocarcinoma cancer patients at stage II and III diagnosed in the two periods 1989–1990 and 2009–2010. The statistical methods included Pearson’s chi-squared test, log-rank test, Cox regression model and propensity score matching. Results: The Cox regression model showed that hazard ratio (HR) of non-surgery dropped from 11.529 to 3.469 in right colon cancer (RCC), 5.214 to 2.652 in left colon cancer (LCC) and 3.275 to 3.269 in rectal cancer (RC) from 1989–1990 to 2009–2010. The 95% confidence intervals (CIs) for surgical resection in 2009–2010 were narrower than those in 1989–1990. HR became greater in LACRC without chemotherapy (from 1.337 to 1.779 in RCC, 1.269 to 2.017 in LCC, 1.317 to 1.811 in RC). There was no overlapping about the 95% CI of chemotherapy between the two groups. The progress of surgery was not linked to the improvement of overall survival (OS) of RCC ( p = 0.303) and RC ( p = 0.660). Chemotherapy had a significant association with OS of all colorectal cancer (CRC) patients ( p = 0.017 in RCC; p = 0.006 in LCC; p = 0.001 in RC). Conclusions: Advancements in chemotherapy regimen were the main contributor to the upswing of CRC survival. The improvements in surgery had a limited effect on improvements in CRC survival.

scholarly journals Impact of old age on resectable colorectal cancer outcomes

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6350 ◽  
Author(s):  
Jianfei Fu ◽  
Hang Ruan ◽  
Hongjuan Zheng ◽  
Cheng Cai ◽  
Shishi Zhou ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Regression Model ◽  
Old Age ◽  
Older Patients ◽  
Cox Regression ◽  
External Validation ◽  
Seer Database ◽  
Cancer Specific Survival ◽  
Cox Regression Model ◽  
The Impact

Objective This study was performed to identify a reasonable cutoff age for defining older patients with colorectal cancer (CRC) and to examine whether old age was related with increased colorectal cancer-specific death (CSD) and poor colorectal cancer-specific survival (CSS). Methods A total of 76,858 eligible patients from the surveillance, epidemiology, and end results (SEER) database were included in this study. The Cox proportional hazard regression model and the Chow test were used to determine a suitable cutoff age for defining the older group. Furthermore, a propensity score matching analysis was performed to adjust for heterogeneity between groups. A competing risk regression model was used to explore the impact of age on CSD and non-colorectal cancer-specific death (non-CSD). Kaplan–Meier survival curves were plotted to compare CSS between groups. Also, a Cox regression model was used to validate the results. External validation was performed on data from 1998 to 2003 retrieved from the SEER database. Results Based on a cutoff age of 70 years, the examined cohort of patients was classified into a younger group (n = 51,915, <70 years of old) and an older group (n = 24,943, ≥70 years of old). Compared with younger patients, older patients were more likely to have fewer lymph nodes sampled and were less likely to receive chemotherapy and radiotherapy. When adjusted for other covariates, age-dependent differences of 5-year CSD and 5-year non-CSD were significant in the younger and older groups (15.84% and 22.42%, P < 0.001; 5.21% and 14.21%, P < 0.001). Also an age of ≥70 years remained associated with worse CSS comparing with younger group (subdistribution hazard ratio, 1.51 95% confidence interval (CI) [1.45–1.57], P < 0.001). The Cox regression model as a sensitivity analysis had a similar result. External validation also supported an age of 70 years as a suitable cutoff, and this older group was associated with having reduced CSS and increased CSD. Conclusions A total of 70 is a suitable cutoff age to define those considered as having elderly CRC. Elderly CRC was associated with not only increased non-CSD but also with increased CSD. Further research is needed to provide evidence of whether cases of elderly CRC should receive stronger treatment if possible.

scholarly journals 813. The Reduction of the acquisition rate of carbapenem resistant Acinetobacter baumannii after room privatization in the intensive care unit

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S448-S449
Author(s):  
Jongtak Jung ◽  
Pyoeng Gyun Choe ◽  
Chang Kyung Kang ◽  
Kyung Ho Song ◽  
Wan Beom Park ◽  
...  
Keyword(s):  
Regression Model ◽  
Acinetobacter Baumannii ◽  
Cox Regression ◽  
Univariate Analysis ◽  
Intervention Group ◽  
Feeding Tube ◽  
Control Group ◽  
Cox Regression Model ◽  
Carbapenem Resistant ◽  
Hospital Acquired

Abstract Background Acinetobacter baumannii is one of the major pathogens of hospital-acquired infection recently and hospital outbreaks have been reported worldwide. On September 2017, New intensive care unit(ICU) with only single rooms, remodeling from old ICU with multibed bay rooms, was opened in an acute-care tertiary hospital in Seoul, Korea. We investigated the effect of room privatization in the ICU on the acquisition of carbapenem-resistant Acinetobacter baumannii(CRAB). Methods We retrospectively reviewed medical records of patients who admitted to the medical ICU in a tertiary care university-affiliated 1,800-bed hospital from 1 January 2015 to 1 January 2019. Patients admitted to the medical ICU before the remodeling of the ICU were designated as the control group, and those who admitted to the medical ICU after the remodeling were designated as the intervention group. Then we compared the acquisition rate of CRAB between the control and intervention groups. Patients colonized with CRAB or patients with CRAB identified in screening tests were excluded from the study population. The multivariable Cox regression model was performed using variables with p-values of less than 0.1 in the univariate analysis. Results A total of 1,105 cases admitted to the ICU during the study period were analyzed. CRAB was isolated from 110 cases in the control group(n=687), and 16 cases in the intervention group(n=418). In univariate analysis, room privatization, prior exposure to antibiotics (carbapenem, vancomycin, fluoroquinolone), mechanical ventilation, central venous catheter, tracheostomy, the presence of feeding tube(Levin tube or percutaneous gastrostomy) and the length of ICU stay were significant risk factors for the acquisition of CRAB (p&lt; 0.05). In the multivariable Cox regression model, the presence of feeding tube(Hazard ratio(HR) 4.815, 95% Confidence interval(CI) 1.94-11.96, p=0.001) and room privatization(HR 0.024, 95% CI 0.127-0.396, p=0.000) were independent risk factors. Table 1. Univariate analysis of Carbapenem-resistant Acinetobacter baumannii Table 2. Multivariable Cox regression model of the acquisition of Carbapenem-resistant Acinetobacter baumannii Conclusion In the present study, room privatization of the ICU was correlated with the reduction of CRAB acquisition independently. Remodeling of the ICU to the single room would be an efficient strategy for preventing the spreading of multidrug-resistant organisms and hospital-acquired infection. Disclosures All Authors: No reported disclosures

scholarly journals Testing the proportional hazards assumption in cox regression and dealing with possible non-proportionality in total joint arthroplasty research: methodological perspectives and review

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ilari Kuitunen ◽  
Ville T. Ponkilainen ◽  
Mikko M. Uimonen ◽  
Antti Eskelinen ◽  
Aleksi Reito
Keyword(s):  
Survival Analysis ◽  
Regression Model ◽  
Total Joint Arthroplasty ◽  
Full Text ◽  
Proportional Hazards ◽  
Cox Regression ◽  
Joint Arthroplasty ◽  
Central Research ◽  
Cox Regression Model ◽  
Pubmed Database

Abstract Background Survival analysis and effect of covariates on survival time is a central research interest. Cox proportional hazards regression remains as a gold standard in the survival analysis. The Cox model relies on the assumption of proportional hazards (PH) across different covariates. PH assumptions should be assessed and handled if violated. Our aim was to investigate the reporting of the Cox regression model details and testing of the PH assumption in survival analysis in total joint arthroplasty (TJA) studies. Methods We conducted a review in the PubMed database on 28th August 2019. A total of 1154 studies were identified. The abstracts of these studies were screened for words “cox and “hazard*” and if either was found the abstract was read. The abstract had to fulfill the following criteria to be included in the full-text phase: topic was knee or hip TJA surgery; survival analysis was used, and hazard ratio reported. If all the presented criteria were met, the full-text version of the article was then read. The full-text was included if Cox method was used to analyze TJA survival. After accessing the full-texts 318 articles were included in final analysis. Results The PH assumption was mentioned in 114 of the included studies (36%). KM analysis was used in 281 (88%) studies and the KM curves were presented graphically in 243 of these (87%). In 110 (45%) studies, the KM survival curves crossed in at least one of the presented figures. The most common way to test the PH assumption was to inspect the log-minus-log plots (n = 59). The time-axis division method was the most used corrected model (n = 30) in cox analysis. Of the 318 included studies only 63 (20%) met the following criteria: PH assumption mentioned, PH assumption tested, testing method of the PH assumption named, the result of the testing mentioned, and the Cox regression model corrected, if required. Conclusions Reporting and testing of the PH assumption and dealing with non-proportionality in hip and knee TJA studies was limited. More awareness and education regarding the assumptions behind the used statistical models among researchers, reviewers and editors are needed to improve the quality of TJA research. This could be achieved by better collaboration with methodologists and statisticians and introducing more specific reporting guidelines for TJA studies. Neglecting obvious non-proportionality undermines the overall research efforts since causes of non-proportionality, such as possible underlying pathomechanisms, are not considered and discussed.

scholarly journals FRI0181 ORGAN DAMAGE FREE SURVIVAL IN SOUTHERN CHINESE PATIENTS WITH ACTIVE LUPUS NEPHRITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 674.1-674
Author(s):  
C. C. Mok ◽  
C. S. Sin ◽  
K. C. Hau ◽  
T. H. Kwan
Keyword(s):  
Lupus Nephritis ◽  
Regression Model ◽  
Cox Regression ◽  
Organ Damage ◽  
Renal Survival ◽  
Cox Regression Model ◽  
Free Survival ◽  
Renal Response

Background:The goals of treatment of lupus nephritis (LN) are to induce remission, retard the progression of chronic kidney disease, prevent organ complications and ultimately reduce mortality. Previous cohort studies of LN have mainly focused on the risk of mortality and development of end stage renal failure (ESRF) (renal survival). The cumulative frequency of LN patients who survive without organ damage, which correlates better with the balance between treatment efficacy and toxicity, as well as quality of life, has not been well studied.Objectives:To study the organ damage free survival and its predictive factors in patients with active LN.Methods:Consecutive patients who fulfilled ≥4 ACR/SLICC criteria for SLE and with biopsy proven active LN between 2003 and 2018 were retrospectivey analyzed. Those with organ damage before LN onset were excluded. Data on renal parameters and treatment regimens were collected. Complete renal response (CR) was defined as normalization of serum creatinine (SCr), urine P/Cr (uPCR) <0.5 and inactive urinary sediments. Partial renal response (PR) was defined as ≥50% reduction in uPCR and <25% increase in SCr. Organ damage of SLE was assessed by the ACR/SLICC damage index (SDI). The cumulative risk of having any organ damage or mortality since LN was studied by Kaplan-Meier’s analysis. Factors associated with a poor outcome were studied by a forward stepwise Cox regression model, with entry of covariates with p<0.05 and removal with p>0.10.Results:273 LN patients were identified but 64 were excluded (organ damage before LN onset). 211 LN patients were studied (92% women; age at SLE 30.4±13.5 years; SLE duration at LN 1.9±3.1years). 47 (22%) patients had nephrotic syndrome and 60 (29%) were hypertensive. Histological LN classes was: III/IV±V (75.1%), I/II (7.8%) and pure V (17.1%) (histologic activity and chronicity score 7.0±4.2 and 1.8±1.5, respectively). Induction regimens were: prednisolone (33.1±17.5mg/day) in combination with intravenous cyclophosphamide (CYC) (21.4%; 1.0±0.2g per pulse), oral CYC (8.6%; 96.4±37.8mg/day), azathioprine (AZA) (14.3%; 78.6±25.2mg/day), mycophenolate mofetil (MMF) (22.8%; 1.9±0.43g/day) and tacrolimus (TAC) (17.1%; 4.3±1.1mg/day). After a follow-up of 8.6±5.4 years, 94(45%) patient developed organ damage (SDI≥1) and 21(10%) patients died. The commonest organ damage was renal (36.3%) and musculoskeletal (17.9%), and the causes of death were: infection (38.1%), malignancy (19.0%), cardiovascular events (9.5%) and ESRF complications (9.5%). At last visit, 114 (55%) patients survived without any organ damage. The cumulative organ damage free survival at 5, 10 and 15 years after renal biopsy was 73.5%, 59.6% and 48.3%, respectively. The 5, 10 and 15-year renal survival rate were 95.2%, 92.0% and 84.1% respectively. In a Cox regression model, nephritic relapse (HR 3.72[1.78-7.77]), proteinuric relapse (HR 2.30[1.07-4.95]) and older age (HR 1.89[1.05-3.37]) were associated with either organ damage or mortality, whereas CR (HR 0.25[0.12-0.50]) at month 12 were associated with organ damage free survival. Baseline SCr, uPCR and histological LN classes were not significantly associated with a poor outcome. Among patients with class III/IV LN, the long-term organ damage free survival were not significantly different in users of MMF (reference) from CYC (IV/oral) (HR 1.45[0.76- 2.75]) or TAC (HR 1.03[0.26-1.62]) as induction therapy.Conclusion:Organ damage free survival is achieved in 55% of patients with active LN upon 9 years of follow-up. CYC/MMF/TAC based induction regimens did not differ for the long-term outcome of LN. Targeting complete renal response and preventing renal relapses remain important goals of LN treatment.Acknowledgments:NILDisclosure of Interests:None declared

The effect of censoring on a multivariate cox regression model comparing surgical and medical treatment for aortic disease patients

1998 ◽  
Vol 19 (3) ◽  
pp. S78-S79
Author(s):  
Charles Oprian ◽  
Kwan Hur ◽  
William Henderson ◽  
Bharat Thakkar ◽  
Frederick Masoudi ◽  
...  
Keyword(s):  
Medical Treatment ◽  
Regression Model ◽  
Cox Regression ◽  
Aortic Disease ◽  
Cox Regression Model

scholarly journals Cox regression survival analysis with compositional covariates: Application to modelling mortality risk from 24-h physical activity patterns

2019 ◽  
Vol 29 (5) ◽  
pp. 1447-1465 ◽  
Author(s):  
DE McGregor ◽  
J Palarea-Albaladejo ◽  
PM Dall ◽  
K Hron ◽  
SFM Chastin
Keyword(s):  
Public Health ◽  
Physical Activity ◽  
Survival Analysis ◽  
Regression Model ◽  
Cox Regression ◽  
Public Health Problem ◽  
Sitting Time ◽  
Cox Regression Model ◽  
Log Ratio ◽  
Activity Behaviour

Survival analysis is commonly conducted in medical and public health research to assess the association of an exposure or intervention with a hard end outcome such as mortality. The Cox (proportional hazards) regression model is probably the most popular statistical tool used in this context. However, when the exposure includes compositional covariables (that is, variables representing a relative makeup such as a nutritional or physical activity behaviour composition), some basic assumptions of the Cox regression model and associated significance tests are violated. Compositional variables involve an intrinsic interplay between one another which precludes results and conclusions based on considering them in isolation as is ordinarily done. In this work, we introduce a formulation of the Cox regression model in terms of log-ratio coordinates which suitably deals with the constraints of compositional covariates, facilitates the use of common statistical inference methods, and allows for scientifically meaningful interpretations. We illustrate its practical application to a public health problem: the estimation of the mortality hazard associated with the composition of daily activity behaviour (physical activity, sitting time and sleep) using data from the U.S. National Health and Nutrition Examination Survey (NHANES).

Adjusted score functions for monotone likelihood in the Cox regression model

2020 ◽  
Vol 39 (10) ◽  
pp. 1558-1572
Author(s):  
Euloge C. Kenne Pagui ◽  
Enrico A. Colosimo
Keyword(s):  
Regression Model ◽  
Cox Regression ◽  
Cox Regression Model ◽  
Score Functions ◽  
Adjusted Score

scholarly journals Prosthetic complications of fixed dental prostheses supported by locking-taper implants: A retrospective study with a mean follow-up of 5 years.

2021 ◽  
Author(s):  
Wen Mo Gao ◽  
Wei Geng ◽  
Chen Chen Luo
Keyword(s):  
Retrospective Study ◽  
Bone Loss ◽  
Regression Model ◽  
Protective Factor ◽  
Cox Regression ◽  
Marginal Bone Loss ◽  
Cox Regression Model ◽  
Prosthetic Complications ◽  
Free Rate

Abstract Background: Restoration with locking-taper implants is a widely used methodology. However, relatively few have examined conical connection systems like locking-taper implant systems. This study provides a retrospective study of locking-taper fixed restorations, mainly focused on prosthetic complications.Methods: All patients who underwent conical connected implants from 2008–2010 were examined. Preparation of the implant sites was performed according to the standard procedures for the Bicon system. The bone healing took over 6 months, and the prosthetic procedure was initiated thereafter. Integrated abutment crowns or gold porcelain crowns were used, and the prosthesis type was a single crown or a fixed dental prosthesis. Once the crown was in place, its occlusion was thoroughly checked and adjusted, and then the crown was glazed or finely polished. The Kaplan-Meier method was used to calculate the cumulative complication-free rates for 5 and 10 years. Additionally, a Cox regression model was used to identify the factors that independently influenced the results. Implant survival and marginal bone loss were also investigated.Results: A total of 392 patients who underwent 541 implants and 434 locking taper implant-based restorations from 2008–2010 were examined. The overall 5-year cumulative complication-free rate was 83.34%. The most common prosthetic complication was veneer chipping, with a frequency of 67.53%. According to the Cox regression model, the complication-free rate of integrated abutment crowns was significantly higher than gold porcelain crowns, molar regions was significantly higher than premolar regions, and females was significantly higher than males. Only three implant failures happened, and a mean marginal bone loss at 1- year, 5-year and 10- year was 0.25mm（95%CI：±0.12）, 0.40mm （95%CI：±0.03）and 0.51mm（95%CI：±0.05）, respectively.Conclusion: Veneer chipping was the most common complication with locking-taper implants supported fixed restorations. According to the result of Cox regression model, gold porcelain crowns are a protective factor relative to integrated abutment crowns, male sex is a protective factor relative to female sex, and premolar prosthetics are a protective factor relative to molar prosthetics. The long-term clinical effect of locking-taper implant is stable, and the implant success rate can meet the clinical needs. The bone tissue level around the implant can maintain long-term stability.

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