Risks of adverse events in colorectal patients: population-based study

Postoperative (PO) outcomes are rapidly being integrated into value-based purchasing programs and associated penalties are slated for inclusion in the near future. Colorectal surgery procedures are extremely common and account for a high proportion of morbidity among general surgery. We sought to assess adverse events in colorectal surgical patients.

We performed a retrospective study using the Nationwide Inpatient Sample database, 2008-2012. Patients were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes and classified based on procedure indication: colon cancer, benign polyps, diverticulitis, inflammatory bowel disease, and ischemic colitis. The outcome of interest was inpatient adverse event identified by Agency for Healthcare Research and Quality's patient safety indicators (PSIs).

We identified 1,100,184 colorectal patients who underwent major surgery; 2.7% developed a PSI during their hospital stay. Compared to all colorectal patients, those with ischemic colitis had significantly higher risk-adjusted rates per 1000 case for pressure ulcer (50.20), failure to rescue (211.30), central line bloodstream infection (2.33) and PO DE/deep vein thrombosis (16.02), and sepsis (46.99), whereas benign polyps were associated with significantly lower risk-adjusted rates per 1000 cases for pressure ulcer (11.48), failure to rescue (84.79), central line bloodstream infection (0.97) and PO pulmonary embolism/deep vein thrombosis (4.81), and sepsis (11.23). Compared to both patient demographic and clinical characteristics, the procedure indication was the strongest predictor of any PSI relevant to colorectal surgery; patients with ischemic colitis had higher odds of experiencing a PSI (odds ratio, 1.84; 95% confidence interval, 1.71-1.99) compared with cancer patients.

Among colorectal surgery patients, inpatient events were not uncommon. We found important differential rates of adverse events by diagnostic category, with the highest odds ratio occurring in patients undergoing surgery for ischemic colitis. Our work elaborates the need for rigorous risk adjustment, quality improvement strategies for high-risk populations, and attention to detail in calculating financial incentives in emerging value-based purchasing programs.