Age versus American society of anesthesiologists – Examining 30-day mortality and morbidity in elderly patients undergoing colectomy from the American college of surgeons national surgical quality improvement program

Background: As the percentage of the population that is elderly increases, colorectal operations performed in this age group are becoming more common. This study examined the use of the American Society of Anesthesiologists (ASA) Classification System (class) as a predictor of 30-day morbidity and mortality in patients ≥90 years old. Objective: The objective of this study was to evaluate the use of ASA classification in elderly patients undergoing colorectal surgery to determine whether it is an accurate predictor of perioperative risk. Design and Setting: This was a retrospective database review. Patients and Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried for all colectomies, coloproctectomies, and proctectomies performed from 2005 to 2009. Demographic and perioperative information including class and 30-day outcomes were assessed. A multiple logistic regression model was used to calculate the odds of 30-day morbidity and mortality correlated with age, class procedure type (open vs. minimally invasive), and do not resuscitate (DNR) status. Main Outcome Measures: 30-day mortality and 30-day morbidity. Sample Size: The sample size included 73,974 patients. Results: A total of 73,974 patients were identified including 1276 patients ≥90 years old. Across all patients, multiple logistic regression demonstrated higher odds of 30-day mortality with increase in class (P < 0.001, odds ratio [OR] 5.62), age (P < 0.001, OR 1.04), DNR status (P < 0.001, OR 3.01), and open procedures (P < 0.001, OR 2.60). Subgroup analysis of patients with class ≤3 showed increase in 30-day mortality with increased age (P < 0.001, OR 1.05), class (P < 0.001, OR 3.87), DNR status (P < 0.001, OR 5.05), and open procedures (P < 0.001, OR 2.39). For patients ≥90 with class ≤3, class was no longer correlated with 30-day mortality (P = 0.251) or morbidity (P = 0.236). Conclusions: In colorectal surgery patients, class is a validated predictor of morbidity and mortality. For the most elderly patients, class indicative of preoperative status of less than a constant threat to life (≤3) increasing class does not correlate with increased morbidity or mortality. Ongoing work is needed to define predictors of risk in these patients. Limitations: This is a retrospective study derived on data retrieved from a national database; we are limited to the preselected variables collected and the potential for missed or omitted patients.