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BACKGROUND:If the future of hospital and physician reimbursement of medicare is to be based on pay-for-performance and/or hospital safety and quality measures (process and outcome measures that do not factor for risk), gastrointestinal surgeons must demand an integration of patient and procedure-specific models into the reimbursement equation. Current risk prediction models utilized by the U.S. involve cumbersome equations of a multitude of variables. An assessment by National Surgical Quality Improvement Program (NSQIP) organizers published in 2008 (JACS 207:777-782), suggest risk should be accounted for by collecting 5-10 measures. We propose that the validated British model, CR-POSSUM, for risk stratification in colon and rectal surgery can be assessed, possibly in combination with ASA (American Society of Anesthesiologists score) and BMI (body mass index), to predict operative risk.METHODS:CR-POSSUM, Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity uses 6 physiologic (age, cardiac, systolic pressure, heart rate, hemoglobin and urea level) and 4 operative (operation type, peritoneal contamination, malignancy status and operative urgency) parameters to calculate risk of morbidity and mortality from colorectal surgery. From a systematic sample of 112 inpatients on the colon and rectal surgery service at our institution over a 5-year period, we calculated CR-POSSUM scores using the web-based algorithm [www.riskprediction.org.uk]. We also noted ASA score and BMI. STATA9 was used to calculate differences in means using two-sided t-tests.RESULTS:Preoperative risk by CR-POSSUM was relatively stable over time, as was BMI and ASA [see table]. CR-POSSUM scores for obese (BMI>=30) and morbidly obese (BMI>=35) patients did not vary significantly (P=0.08 and 0.57, respectively), indicating it is an independent factor. CR-POSSUM scores varied significantly by ASA score: ASA 1-2 mean 4.1 (SD 8.2) versus mean 7.9 (SD 8.1) for ASA 3-4 patients (P=0.03).CONCLUSIONS:From this preliminary work, we propose that Medicare policy-makers consider this simple, validated, European-developed risk stratification for patients undergoing lower gastrointestinal surgery. Obesity is an increasing epidemic in the U.S. and should be given its due role in the equation, while ASA could be left out. We will present morbidity/mortality data on this group to relate CR-POSSUM scoring to our surgical outcomes.
Preoperative CR-POSSUM Scores, ASA, and BMI over 5 years of a Systematic Sample of Colon and Rectal Surgery Inpatients

YEAR	N	CR-POSSUM, mean(range)	ASA, mean	BMI, mean (range)
2006	36	3.9 (0.3-18.6)	2.25	27.9 (20-49)
2007	23	8.0 (0.7-57.6)	2.4	27.2 (19-45)
2008	18	5.6 (0.3-22.5)	2.4	28.6 (18-41)
2009	15	4.6 (0.9-22.0)	2.4	27.1 (20-44)
2010	20	7.4 (0.4-26.0)	2.4	25.5 (17-35)
TOTAL	112	5.7 (0.3-57.6)	2.4	27.3 (17-49)

(no significant variation over time)