The Impact of ICD-9-CM Code Rank Order on the Estimated Prevalence of Clostridium difficile Infections

Abstract

Compared with the NHDS definition, the NIS definition captured 12% more CDI cases and reported significantly higher CDI rates. Rates calculated using toxin assay results were not different from rates calculated using NHDS criteria, but CDI prevalence appeared to increase more rapidly when measured by NHDS criteria than when measured by toxin assay results.