The contribution of complications to high resource utilization during congenital heart surgery admissions.

Background: The Institutes of Medicine estimates that patient safety events cost the United States between $17 billion and $29 billion annually. Costs associated with patient safety events or complications among congenital heart surgery admissions are understudied.

Objective: To determine the independent contribution of complications on increased resource utilization during congenital heart surgery admissions.

Methods: Data were obtained from the Healthcare Cost and Utilization Project Kids' Inpatient Database year 2000. Cases of congenital heart surgery <18 years of age were identified. High resource use admissions were defined as admissions above the 90th percentile for total hospital charges. Complications were identified by a method published by the Agency for Healthcare Research Quality using ICD-9-CM codes. Multivariate analyses using generalized estimating equations adjusted for previously identified factors associated with high resource use to estimate the independent effect of a complication on high resource use. These factors include: Risk Adjustment for Congenital Heart Surgery risk categories, age, prematurity, major noncardiac structural anomalies, Medicaid, weekend admission, and state. The added explanatory power attributed to a complication diagnosis variable was measured by an increase in the area under the receiver operator characteristic curve (ROC).

Results: Among 10,602 congenital heart surgery admissions identified, the median total charges were $51,125. The threshold for high resource use was total charges >or=$192,272. High resource admissions accounted for >40% of the total charges for all admissions. Complications were identified in 3360 (32%) of congenital heart surgery admissions. Univariate analysis demonstrated that admissions with at least 1 complication diagnosis were more likely to be a high resource use admission (18% vs. 6%, OR 3.0, P < 0.001). Multivariate analyses revealed that admissions with a complication diagnosis were much more likely to exceed the threshold for high resource utilization (OR 3.2, P < 0.001). The addition of the complication variable to the multivariate model increased the area under the ROC curve from 0.837 to 0.863.

Conclusions: Congenital heart surgery admissions with a complication diagnosis are 3 times more likely to exceed $192 272 in total charges despite adjusting for known risk factors for high resource use. Complication reduction may result in both an economic and clinical benefit.