OBJECTIVES: Extraintestinal pathogenic Escherichia coli may cause invasive E. coli disease (IED). This study evaluated the clinical and economic burden of IED among commercially insured adults in the United States.

METHODS: Commercially insured adults (18-64 years) with diagnosis codes indicative of IED were identified in RWD Insights, an all-payer medical and pharmacy claims database, from 01/2018-12/2018. Index date was defined as date of first IED diagnosis. Patients were required to have ≥12 months continuous data capture pre/post-index date. Non-IED patients had no prior evidence of IED. Demographic and clinical characteristics were assessed during 12-month baseline. Preliminary propensity score matching (PSM) was conducted between IED and non-IED cohorts using selected demographic and clinical characteristics with further evaluation and validation of diagnosis categories used in PSM ongoing. Cox proportional hazards model was used to examine time to all-cause death. Generalized linear models were implemented to compare healthcare resource utilization (per patient per year) and costs (per patient per month).

RESULTS: A total of 7,588 IED and 525,736 non-IED patients were included. At baseline, IED patients, compared with non-IED, were older (52.4 vs 44.8 years, p<0.0001), included more females (68.5% vs 57.5%, p<0.0001), and had higher mean Charlson Comorbidity Index score (2.47 vs 0.22, p<0.0001). 85% (n=6,432) of IED patients were treated in inpatient setting, with 25% (n=1,584) receiving ICU care. Post-PSM, IED cohort (N=6,889) incurred significantly higher healthcare costs ($8,645 vs $1,054, p<0.0001) than matched controls, primarily due to inpatient costs ($7,472 vs $1,458, p<0.0001). In the IED cohort, risk of inpatient admission in follow-up was 4.08 times higher (CI: 3.96-4.20, p<0.0001); risk for death was 4.73 times higher (CI: 3.99, 5.62, p <0.001).

CONCLUSIONS: IED was found to be associated with substantial clinical and economic burden, when a cohort of IED cases was compared with matched controls, thus highlighting a critical need for preventative measures.