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

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.

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

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).

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.

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.