Effect of postdischarge morbidity and mortality on comparisons of hospital surgical quality

Hospitals increasingly rely on surgical quality assessment programs that require considerable resources to capture outcomes after hospital discharge. However, it is unclear whether capturing postdischarge complications and deaths is important. Our objectives were (1) to determine the frequency of postdischarge complications and deaths and (2) to determine whether hospital rankings change with inclusion of postdischarge outcomes.

From 181 hospitals participating in the American College of Surgeon's National Surgical Quality Improvement Program, 329,951 patients were identified (2006-2007). Mortality and 19 complications within 30 days of the index operation were categorized as occurring before or after discharge. Risk-adjusted hospital rankings were compared based on whether only predischarge (inpatient) versus both pre- and postdischarge (inpatient and outpatient within 30 days of operation) morbidity and mortality were included.

Postdischarge complications accounted for 32.9% of all complications. Certain complications occurred frequently after discharge: surgical site infections (66.0%), urinary tract infections (39.4%), pulmonary embolisms (42.2%), and deep venous thromboses (34.5%). Of all patients experiencing complications, 39.7% had only postdischarge complications. Of 5827 postoperative deaths, 23.6% occurred after discharge. Hospital quality rankings changed when postdischarge outcomes were excluded versus included for morbidity (median hospital rank change: 16 ranks; interquartile range, 7-36) and mortality (median hospital rank change: 14 ranks; interquartile range, 6-29), and there was disagreement in outlier status designations depending on whether postdischarge events were included (morbidity: kappa = 0.546; mortality: kappa = 0.507).

A substantial proportion of postoperative complications and deaths occur after hospital discharge. Inclusion of postdischarge events considerably affects hospital quality rankings and outlier status designations. Quality improvement programs and research that do not consider postdischarge outcomes may offer incomplete information to hospitals, payers, providers, and patients.