Cost of Hospitalizations for Leading Foodborne Pathogens in the United States: Identification by International Classification of Disease Coding and Variation by Pathogen

Foodborne illness is a continuing public health problem in the United States. Seven pathogens-Campylobacter, Clostridium perfringens, Shiga toxin-producing Escherichia coli O157, Listeria monocytogenes, nontyphoidal Salmonella, norovirus, and Toxoplasma gondii-are estimated to cause >90% of the foodborne illnesses, hospitalizations, and deaths attributed to 31 known pathogens. The purpose of this article was to inform estimates of the cost of hospitalizations associated with these pathogens using National Inpatient Survey data from January 2012 through September 2015. The article explored two methodological issues. First, is it more appropriate to use hospitalizations identified using principal or all diagnosis codes when estimating cost? Second, should pathogen-specific or overall mean cost estimates be used? After excluding C. perfringens because of low sample size, the remaining six pathogens included in the analysis were associated with 17,102 hospital discharge records. Of these 55% have the pathogen listed as a principal diagnosis (FBP-PD), ranging from 6% for T. gondii to 68% for nontyphoidal Salmonella. The mean per-case cost of records with the pathogen listed as a secondary diagnosis (FBP-SD) was 2.7 times higher than FBP-PD. FBP-SD were also more severe than FBP-PD with longer lengths of stay, increasing loss of function, and increasing risk of mortality. Severity was the main driver of cost. We also found severity of illness and cost of hospitalizations vary by pathogen. Based on identifying cases with a pathogen in either FBP-PD or FBP-SD, we found mean per-case hospitalization cost across the six pathogens included in this study was $17,515, ranging from $11,552 for Campylobacter to $34,206 for norovirus. In summary, if only FBP-PD cases were used to estimate cost, estimates would likely underestimate hospitalization costs among those cases with a pathogen-specific diagnosis. Because these foodborne pathogens varied in severity of illness, the mean cost of hospitalizations also varied significantly by pathogen.