Evaluation of the Angus ICD9-CM Sepsis Abstraction Criteria

Objective Validate the infection component of the Angus International Classification of Diseases, Ninth Revision, Clinical Modification (ICD9-CM) sepsis abstraction criteria Design Observational cohort study Setting 55,000 visits/year Adult Emergency Department (ED) Patients All consecutive ED patient visits between 12/16/2011 and 08/13/2012 were included in the study. Patients were excluded if there was a missing outcome measure. Interventions None. Measurements and Main Results The primary outcome measure was suspected infection at conclusion of the ED work-up as judged by the physician. There were 34,796 patients who presented to the ED between 12/16/11 and 8/13/12, of which 31,755 (91%) patients were included and analyzed. The original Angus sepsis abstraction criteria had a sensitivity of 55%, specificity of 97%, PPV of 82%, NPV of 88%, accuracy of 87%, and a F 1 score of 0.66. The modified Angus sepsis abstraction criteria which includes codes added after the original publication had a sensitivity of 65%, specificity of 96%, PPV of 81%, NPV of 91%, accuracy of 89%, and F 1 score of 0.72. Conclusions In our study, the Angus abstraction criteria have high specificity (97%), but moderate sensitivity (55%) in identifying patients with suspected infection as defined by physician at the time of disposition from the emergency department. Given these findings, it is likely that we are underestimating the true incidence of sepsis in the United States and worldwide.