The Establishment As Well As The Clinical Application Of The Assessment System About Mortality After Surgery Of Patients With Colorectal Carcinoma

Background：Colorectal carcinoma is one of the most common malignant tumors ofdigestive tract. According to the epidemiology surveys both at home and abroad, the incidenceof colorectal carcinoma presents a trend of rising year by year, along with the rapiddevelopment of economy and changes in people’s eating habits as well as their surroundings.As for the treatment, surgery is still the most effective and important method. There is alwayssome risk comes along with an operation. That’s why the assessment before the surgery,especially the mortality after surgery means so much. Related assessment system exists butdoesn’t work perfect at presents. For now, four assessment system are most commonly used:POSSUM、P-POSSUM、ACPGBI and Cr-POSSUM. Each one of them has a different gradingstandard which leads to different results. A large number of clinical studies have confirmedthat the Cr-POSSUM assessment system is more accurate than other three systems in theassessment of mortality after surgery in colorectal patients. However, in the view ofdifferent treatment procedures and medical environments, using the same assessment systemseems rather unsuitable. So in order to obtain more accurate result, the former assessmentsystem must be modified. Since the calculating progress of the complication or mortality rateof the operation by using the regression equation of each assessment system is quite acomplex one, operation risk assessment software can be designed with a computer to makethe calculation process programmed and much more simple and convenient for clinicalapplication.Purpose: This subject aims to design a system which is suited to assess the mortality riskof patients with colorectal carcinoma after surgery, while set up the regression equation thatfits it. What’s more, a related software concerning such assessment need to be designed andused in clinical research, which will provide a theoretical basis to ensure a scientific andobjective assessment of the efficacy of surgery for patients with colorectal carcinoma.Methods: Through analyzing the factors that leads to death after surgery in patients withcolorectal carcinoma, we have modified the Cr-POSSUM assessment system and renamed itas C-POSSUM. We also have retrospectively analyzed the complete data of patients withcolorectal carcinoma who had a surgery treatment and recorded total death cases in30days after surgery in fourth section of cadre ward, Lanzhou General Hospital of Lanzhou militaryarea from2011.1to2012.12and grading these cases by C-POSSUM assessment system. Allthe data has been processed by using SPSS17.0statistical software and established aregression equation by Logistic regression analysis. An optimal threshold value of predictingdeath rate can be achieved through the method of using ROC to test the accuracy of theC-POSSUM assessment system. A12-months prospective observational study was conductedfrom2013.1to2013.12, and all the death amounts were recorded and put in Chi-square test.Make P<0.05, then the difference is statistically significant. Finally an assessment system isestablished on death risk in colorectal carcinoma patients’ surgery with the help ofInformation Section.Results:556cases that patients with colorectal carcinoma received surgery wereanalyzed and4of them died with30days after their surgery. Through Logistic regressionanalysis, the regression equation for the calculation of mortality is established:LN[R/(1-R)]=-28.921+(0.361×PS)+(1.542×OSS). R: mortality. The regression model’saccuracy was tested by ROC, which the area under the curve was0.989(0.980-0.998,95%confidence interval). And the optimal threshold value of mortality prediction is8.5%. Aprospective clinical study was performed by among175cases of patients with colorectalcarcinoma,1actual death,3predicted death. Put these figures through Chi square test andthe result shows thatχ2=1.012，P=0.315，P＞0.05,means there is no statistical significance inthe difference between this two group of data.Conclusion:C-POSSUM assessment system can predict mortality of patients with colorectalcarcinoma after surgery precisely;C-POSSUM assessment system software can make fastcalculation and save the data,and easy for clinical use.