Characterizing center-level variation in outcomes after the development of pulmonary complications in elective...

Postoperative pulmonary complications (PCs) affect 5% to 25% of patients who undergo cardiac surgery. Variation in hospital-management strategies and resource availability may contribute to the incidence of PCs. We assessed the association of PCs with clinical outcomes after elective cardiac surgery and hospital-level variation across the United States.

Adults (≥18 years) undergoing elective coronary, valvular, or proximal aortic operations were identified from the 2016-2022 Nationwide Readmissions Database. PC was defined as a composite of postoperative pneumonia, prolonged mechanical ventilation (>24 hours), reintubation, or tracheostomy. Primary outcome was in-hospital mortality; secondary outcomes included length of stay, hospitalization costs, nonhome discharge, and 30-day nonelective readmission. Multivariable logistic and linear regression models were used for risk adjustment. Mixed-effects modeling quantified hospital-level variation, with center-level effects assessed using the intraclass correlation coefficient.

Among 862,984 patients, 38,596 (4.47%) experienced a PC, most commonly pneumonia (11.5%). Patients with PC were older and had greater comorbidity burden (P < .001). After adjustment, PCs were associated with increased odds of in-hospital mortality (adjusted odds ratio, 1.24; 95% CI, 1.08-1.43), prolonged length of stay (β +0.76 days), greater hospitalization costs (β +$3871), and greater likelihood of nonhome discharge (all P < .001). PC was also associated with decreased freedom from 30-day readmission. Hospital-level factors accounted for 15.3% of the observed variation in PC incidence, with greater institutional PC rates correlated with increased hospitalization expenditures.

PCs remain a persistent challenge, driving an increase in mortality and an estimated incremental increase in expenditures of $3800. Significant center-level variation suggests opportunities for quality improvement through targeted interventions addressing modifiable risk factors.