The RACHS-1 risk categories reflect mortality and length of hospital stay in a large German pediatric cardiac surgery population

Abstract

Objectives: The Risk Adjusted classification for Congenital Heart Surgery (RACHS-1) was published in January 2002, based on 4370 operations registered by the Pediatric Cardiac Care Consortium. It is designed for being easily applicable also for retrospective analysis of hospital discharge data sets; the classification was not developed for patients with heart transplantations, ventricular assist devices or patients above 18 years. We apply this classification to our 2368 correspondent procedures that were performed consecutively on 2223 patients between June 1996 and October 2002 in Bad Oeynhausen and analyze its relation to mortality and length of hospital stay.

Methods: The procedures were grouped by the 6 RACHS-1 categories. Groping criteria were mainly the performed procedures; for few procedures age or diagnoses are needed in addition. The classification process itself took less than 10 working hours. Risk group frequencies in our/ the PCCC population were 1: 368/964 (15.5%/22.0%), 2: 831/1433 (35.1%/33.1%), 3: 744/1523 (31.4%/34.7%), 4: 284/276 (12.0%/6.3%), 5: 4/4 (0.2%/0.1%), 6: 137/168 (5.3%/3.8%). 18.8%/19.2% were under 1 month, 37.5%/31.6% 1-12 months of age, respectively.

Results: Hospital mortality (%) in our population/ the PCCC Group 1-6 was: 0.3/0.4, 4.0/3.8, 5.6/8.5, 9.9/19.4, 50.0/0, 40.1/47.7%. Geometric means of total (13.1, 19.6, 23.5, 29.1, 31.5, 52.6 days, respectively) and postoperative length of stay of survivors show significant differences between the single risk groups. The prediction capacity of the score as expressed by the area under the receiver-operator curve was nearly equal to the value found for the American hospital discharge data sets. Length of stay rises exponentially with the RACHS-1 category. However, the RACHS-1 category explains only 13.5% of the total and 16.8% of individual postoperative lengths of hospital stay in survivors.

Conclusion: The RACHS-1 classification is applicable to European pediatric populations, too. Category Distribution, outcome class distinction capacity, distribution and mortality are similar. RACHS-1 is able to classify patients into significantly different groups concerning total and postoperative hospital stay duration, although there remains a large variability within the groups.