Identifying Pediatric Severe Sepsis and Septic Shock: Accuracy of Diagnosis Codes

Abstract

Objectives: To evaluate accuracy of 2 established administrative methods of identifying children with sepsis using a medical record review reference standard.

Study design: Multicenter retrospective study at 6 US children's hospitals. Subjects were children >60 days to <19 years of age and identified in 4 groups based on International Classification of Diseases, Ninth Revision, Clinical Modification codes: (1) severe sepsis/septic shock (sepsis codes); (2) infection plus organ dysfunction (combination codes); (3) subjects without codes for infection, organ dysfunction, or severe sepsis; and (4) infection but not severe sepsis or organ dysfunction. Combination codes were allowed, but not required within the sepsis codes group. We determined the presence of reference standard severe sepsis according to consensus criteria. Logistic regression was performed to determine whether addition of codes for sepsis therapies improved case identification.

Results: A total of 130 out of 432 subjects met reference SD of severe sepsis. Sepsis codes had sensitivity 73% (95% CI 70-86), specificity 92% (95% CI 87-95), and positive predictive value 79% (95% CI 70-86). Combination codes had sensitivity 15% (95% CI 9-22), specificity 71% (95% CI 65-76), and positive predictive value 18% (95% CI 11-27). Slight improvements in model characteristics were observed when codes for vasoactive medications and endotracheal intubation were added to sepsis codes (c-statistic 0.83 vs 0.87, P = .008).

Conclusions: Sepsis specific International Classification of Diseases, Ninth Revision, Clinical Modification codes identify pediatric patients with severe sepsis in administrative data more accurately than a combination of codes for infection plus organ dysfunction.

Figure. Schema of study process

Sepsis code group is subjects with ICD9-CM codes for severe sepsis or septic shock. Combination code group is subjects with ICD9-CM codes for infection plus organ dysfunction. Control group 1 is subjects without ICD9-CM codes for sepsis, infection, or organ dysfunction matched to sepsis code subjects on date of hospital admission. Control group 2 is subjects with ICD9-CM codes for infection but not sepsis or organ dysfunction matched to the sepsis code group based on admission status to the intensive care unit or regular inpatient floor. Medical record review was performed blind to group assignment.