In-hospital Medical Costs of Infections Caused by Carbapenem-resistant Klebsiella pneumoniae

Background. Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a major health threat, but the economic impact of carbapenem resistance in K. pneumoniae infections remains largely uninvestigated. Methods. We constructed a retrospective cohort of all patients hospitalized at West China Hospital in 2017 who had CRKP- or carbapenem-susceptible K. pneumoniae (CSKP)-positive clinical samples. Propensity score matching (PSM) was used to control the impact of potential confounding variables, including demographics, comorbidities, and treatment, and to observe the impact of factors other than length of stay (LOS). Patients who survived were subjected to subgroup analyses stratified by infection type. Results. There were 267 patients with CRKP and 1328 with CSKP. Patients with CRKP had a higher crude in-hospital mortality rate (14.61% vs 5.65%, P < .05) and longer LOS (median, 31 vs 19 days; P < .05). PSM for demographics, comorbidities, and treatment generated 237 pairs. Patients with CRKP had higher medical costs than those with CSKP during the entire hospitalization (median, in US dollars, $22 962 vs $11 755, respectively; P < .05) and during the period after infection (median, $9215 vs $6904, respectively; P < .05). When LOS was matched, patients with CRKP still had high excess costs compared to those with CSKP(median, $22 917 vs $13 851, respectively, for the entire hospitalization, P < .05; $9101 vs $7001, respectively, after infection, P < .05). For infection type, the sample size generated sufficient power to compare only the patients with pneumonia. For surviving patients, high excess costs were observed in those with pneumonia caused by CRKP as compared to CSKP ($21 890 vs $11 698, respectively, for the entire hospitalization, P < .05; $9773 vs $5298, respectively, after infection, P < .05). Medicines other than antibacterial agents and nonmedicinal therapies contributed most (57.8%) of the excess costs associated with CRKP. Conclusions. Carbapenem resistance in K. pneumoniae was associated with increased medical costs not accounted for by the cost of antimicrobial therapy.