Assessment of Administrative Medical Claims Data for Public Health Surveillance of Invasive Group A Streptococcal Necrotizing Fasciitis in Tennessee.

OBJECTIVE: Necrotizing fasciitis (NF) is a severe manifestation of invasive group A streptococcal (iGAS) infection. NF is a rapidly progressive infection of the subcutaneous tissues, including the fascia, and accurate diagnosis and prompt treatment are critical. Population-based surveillance is conducted for iGAS, including the severe manifestations of NF, by the federally funded Active Bacterial Core surveillance (ABCs) program. METHODS: We used administrative claims data from a large managed care organization in Tennessee to enhance the public health surveillance for NF iGAS. For the period 2003-2012, we identified cases of NF in Tennessee by searching the claims database for diagnostic codes indicating the diagnosis of NF. We compared these cases with cases detected in selected Tennessee counties by ABCs. RESULTS: Of 356 managed care patients with a diagnostic code indicating NF, we determined that 20 (6%) patients had been hospitalized with iGAS infection and, therefore, were likely to be true NF cases. Of these 20 patients, only 11 matched with patients identified by ABCs; nine patients had not been previously identified by ABCs. During the same time period, 54 patients with NF were ascertained by ABCs. CONCLUSION: Administrative claims data have the potential to augment disease surveillance but require a large investment in resources compared with the few NF cases identified.