An Evaluation of the Influenza Hospitalization Surveillance Network (IHSN)

Abstract

The Influenza Hospitalization Surveillance Network (IHSN or FluSurv-NET) was evaluated using the Centers for Disease Control and Prevention's (CDC) guidelines for evaluating a public health surveillance system. The IHSN was evaluated for usefulness, simplicity, flexibility, data quality, acceptability, sensitivity, positive predictive value, representativeness, timeliness, and stability. The IHSN was found to utilize a broad range of sources for influenza surveillance which can be openly accessed via the CDC's "FluView" online application. The IHSN is highly adaptable with its capacity to accommodate additional data sources when needed. The overinclusiveness of different laboratory diagnostic methodologies was found to be detrimental to the overall data quality of the IHSN in the form of variable sensitivity and positive predictive value measures amongst the CDC's acceptable testing methods. Overall, the IHSN is a very robust system that allows for timely access to influenza data by public health officials. However, the inclusivity of the IHSN causes it to fall short when considering the importance of consistency in data collection practices. The IHSN fails to take into account several factors that could either artificially increase, or decrease case counts. We recommend the IHSN integrate a more streamlined and reliable data collection process and standardize its expectations with all of its reporting sites.