Intended and unintended effects of large-scale adverse event disclosure: a controlled before-after analysis of five large-scale notifications

Background and objective How patients respond to being notified of a large-scale adverse event (LSAE), such as improper sterilisation of medical equipment that exposes them to bloodborne pathogens, is not well known. The objective of this study was to determine, using administrative data, the intended and unintended consequences of patient notification following a LSAE. Methods We examined five LSAEs where patients may have been inadvertently exposed to hepatitis C virus (HCV), HIV, and hepatitis B virus (HBV). A total of 9638 cases were identified at five Department of Veteran Affairs (VA) medical facilities between 2009 and 2012. We identified controls at the same facility prior to the exposure period and at neighbouring facilities (n=45 274). Difference-in-differences models were used with Veterans Health Administration (VHA) and Medicare data to examine infectious disease testing rates and subsequent utilisation patterns. Results Receipt of a LSAE notification was associated with a 73.2, 76.8 and 77.1 adjusted percentage point increase for HCV, HIV and HBV testing, respectively (all p