Evaluation of failure to rescue as a quality metric in pediatric heart surgery: an analysis of the STS Congenital Heart Surgery Database

Abstract

Background: Failure to rescue (FTR; the probability of death after a complication) has been adopted as a quality metric in adult cardiac surgery, in which it has been shown that high-performing centers with low mortality rates do not have fewer complications, but rather lower mortality in those who experience a complication (lower FTR). It is unknown whether this holds true in pediatric heart surgery. We characterized the relationship between complications, FTR, and mortality in this population.

Methods: Children (0 to 18 years) undergoing heart surgery at centers participating in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2006 to 2009) were included. Outcomes were examined in multivariable analysis adjusting for patient characteristics, surgical risk category, and within-center clustering.

Results: This study included 40,930 patients from 72 centers. Overall in-hospital mortality was 3.7%, 39.3% had a postoperative complication, and the FTR rate (number of deaths in those with a complication) was 9.1%. When hospitals were characterized by in-hospital mortality rate, there was no difference across hospital mortality tertiles in the complication rate in adjusted analysis; however, hospitals in the lowest mortality tertile had significantly lower FTR rates (6.6% versus 12.4%; p<0.0001). Similar results were seen when evaluating high-severity complications and across surgical risk groups.

Conclusions: This analysis suggests that hospitals with low mortality rates do not have fewer complications after pediatric heart surgery, but instead have lower mortality in those who experience a complication (lower FTR). Further investigation into FTR as a quality metric in pediatric heart surgery is warranted.

Fig 1

(A) Adjusted complication rate and (B) adjusted failure to rescue rate. Data are adjusted for patient characteristics as outlined in the methods section, and shown for each hospital mortality tertile (defined based on adjusted mortality rate).

Fig 2

Correlation between measures. Scatterplots demonstrate the relationship between hospital rank for mortality rate versus (A) complication rate, and hospital rank for mortality rate versus (B) failure to rescue (FTR) rate. All measures are adjusted for the patient characteristics outlined in the methods.

Fig 3

Sensitivity analysis showing the relationship of hospital mortality with complications and failure to rescue excluding centers at extremes of complication coding. Adjusted odds ratios (black boxes), and 95% confidence intervals (lines) comparing (A) complications and (B) failure to rescue across hospital mortality tertiles are presented for the overall cohort and for the subgroup of hospitals remaining after those at the extremes of the distribution of complication coding were excluded as described in the methods. In both cohorts, there is no significant relationship between hospital mortality and complications; however, there is a significant association of failure to rescue with hospital mortality.