Abstract 263 Poster Session III, Monday, 5/3 (poster 90)

Context. Pediatric intensive care units (PICUs) have expanded nationally, yet few studies have examined the potential impact of regionalization and no study has demonstrated whether a relationship between patient volume and outcome exists in these units.

Objective. This study examines relationships between the volume of patients and other unit characteristics on patient outcomes in pediatric intensive care units. Specifically, we investigate whether an inverse relationship exists between patient volume in PICUs and risk adjusted mortality and patient length of stay.

Methods. A prospective multi-center cohort design was employed using 16 pediatric intensive care units. All of the units participated in the Pediatric Critical Care Study Group. Data was collected on consecutive admissions to the 16 units with no exclusions beginning January 1993 and continuing for 12 months (N=11,106). PICU volume was measured as the number of patients per bed year. Risk-adjusted mortality and length of stay were examined in multivariate analyses. The multivariate models used the Pediatric Risk of Mortality (PRISM) score and other measures to risk-adjust for illness severity and case-mix differences.

Results. We found significant effects of patient volume on both risk-adjusted mortality and patient length of stay. Volume ranged from 36 to 86 patients per bed per year and a one standard deviation increase in patient volume was associated with a decrease in risk-adjusted mortality (adjusted odds ratio [OR] 0.71; 95% confidence interval [CI] 0.57-0.89). PICUs with patient volume exceeding 40 patients per bed had better risk-adjusted outcomes (adjusted OR 0.70; 95% CI 0.50-0.98). PICUs with patient volume exceeding 47 patients per bed had lower risk-adjusted lengths of stay. Other PICU characteristics such as a fellowship training program, university affiliation, and children's hospital affiliation, had little effect on patient length of stay and no effect on risk-adjusted mortality.

Conclusions. The volume of patients in pediatric intensive care units is inversely related to risk adjusted mortality and patient length of stay. Regionalization of PICU services may improve patient quality and efficiency. Alternatively, high quality PICUs may attract a greater volume of patients.