Enhanced Influenza Surveillance Using Telephone Triage and Electronic Syndromic Surveillance in the Department of Veterans Affairs, 2011-2015.

Telephone triage (TT) is a method whereby medical professionals speak by telephone to patients to assess their symptoms or health concerns and offer advice. These services are often administered through an electronic TT system, which guides TT professionals during the encounter through the use of structured protocols and algorithms to help determine the severity of the patients' health issue and refer them to appropriate care. TT is also an emerging data source for public health surveillance of infectious and noninfectious diseases, including influenza. We calculated Spearman correlation coefficients to compare the weekly number of US Department of Veterans Affairs (VA) TT calls with other conventional influenza measures for the 2011-2012 through 2014-2015 influenza seasons, for which there were a total of 35 666 influenza-coded TT encounters. Influenza-coded calls were strongly correlated with weekly VA influenza-coded hospitalizations (0.85), emergency department visits (0.90), influenza-like illness outpatient visits (0.92), influenza tests performed (0.86), positive influenza tests (0.82), and influenza antiviral prescriptions (0.89). The correlation between VA-TT and Centers for Disease Control and Prevention (CDC) national data for weekly influenza hospitalizations, influenza tests performed, and positive influenza tests was also strong. TT correlates well with VA health care use and CDC data and is a timely data source for monitoring influenza activity.