Preoperative risk stratification for mortality and major morbidity in major colorectal surgery.
BACKGROUND
Risk stratification in major colorectal surgery, in general, has used preoperative, intraoperative, and postoperative variables, and has been used for purposes of comparative audit. To enable preoperative clinical use, this study aimed to stratify risk by use of preoperative risk factors only.


METHODS
This is a single-institutional prospective observational study.


RESULTS
There were 887 major colorectal procedures assessed. Independent risk factors for mortality were American Society of Anesthesiologists' physical status Grades III to V, age, high comorbidity count, and low surgeon case volume. For major morbidity, risk factors were American Society of Anesthesiologists' Grades III to V, urgent operation, and operation to excise the rectum. Overall, mortality was 4.51%, and major morbidity was 19.6%. The estimated risk of mortality was stratified by risk factor profile from 0.12% (95% CI, 0.02-0.93) to 42.4% (95% CI, 23.5-63.9). The risk of major morbidity was stratified from 7.22% (95% CI, 4.82-10.7) to 49.2% (95% CI, 34.2-64.4). Model discrimination was favorable to the existing risk adjustment models applied to our cohort. The Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (including Portsmouth and ColoRectal modifications), and Association of ColoProctology of Great Britain and Ireland Colorectal Cancer models (mortality: area under receiver operating characteristic (AU ROC) curves 0.87 compare 0.70-0.81, major morbidity: 0.69 compare 0.66)).


CONCLUSIONS
Simple and readily available preoperative risk factors can achieve risk stratification. Risk stratification based on preoperative risk factors only possibly has comparable efficacy with those models that use preoperative, intraoperative, and postoperative risk factors.
Ragg
Joseph L
JL
Department of Surgery, Barwon Health, Geelong, Victoria, Australia. joeragg@gmail.com
Watters
David A
DA
Guest
Glenn D
GD
D000368:Aged; D015331:Cohort Studies; D003108:Colonic Diseases / Q000150:complications / Q000401:mortality / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000009:adverse effects* / Q000401:mortality*; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects / Q000401:mortality; D007813:Laparotomy / Q000009:adverse effects / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012002:Rectal Diseases / Q000150:complications / Q000401:mortality / Q000601:surgery*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors