The Comparative Epidemiology of Pediatric Severe Sepsis

Objective: To determine whether the coding strategies used to identify severe sepsis in administrative data sets could identify cases with comparable case mix, hospitalization characteristics, and outcomes as a cohort of children diagnosed with severe sepsis using strict clinical criteria. Methods: We performed a retrospective cohort study using data from 2005 to 2011 from the New York and Florida State Inpatient Databases, available from the US Healthcare Cost and Utilization Project. We compared 4 coding strategies: the single International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for (1) severe sepsis or (2) septic shock, and the algorithms developed by (3) Angus et al or (4) Martin et al, which use a combination of ICD-9-CM codes for infection and organ dysfunction. We compared the cases identified by each strategy with each other and with children enrolled in the REsearching severe Sepsis and Organ dysfunction in children: a gLobal perspectiVE (RESOLVE) trial. Results: The Angus criteria was 9 times larger (n = 23 995) than the smallest cohort, identified by the “septic shock” code (n = 2 601). Cases identified by the Angus and Martin strategies had low mortality rates, while the cases identified by the “severe sepsis” and “septic shock” codes had much higher mortality at all time points (eg, 28-day mortality of 4.4% and 7.4% vs 15.4% and 16.0%, respectively). Mortality in the “severe sepsis” and “septic shock” code cohorts was similar to that presented in the RESOLVE trial. Conclusions: The ICD-9-CM codes for “severe sepsis” and “septic shock” identify smaller but higher acuity cohorts of patients that more closely resemble the children enrolled in the largest clinical trial of pediatric severe sepsis to date.