ATTRIBUTABLE HEALTH CARE RESOURCE UTILIZATION AND COSTS FOR PATIENTS WITH PRIMARY AND RECURRENT CLOSTRIDIUM DIFFICILE INFECTION IN THE UNITED STATES

Abstract

Clostridium difficile infection (CDI) caused 453,000 new and 83,000 recurrent infections, and was associated with about 29,000 deaths in 2011 in the US. The economic burden attributable to CDI, especially recurrent CDI, is not well understood. Our objectives were to understand patient characteristics, and to estimate the attributable healthcare resource utilization (HCRU) and cost associated with primary and recurrent CDI. We conducted a retrospective, observational database (MarketScan®) study. The cohort included all patients with a CDI diagnosis (ICD-9 diagnosis=008.45) from July 1, 2010 to June 30, 2014 (the earliest diagnosis date was defined as the index date), were continuously enrolled for 12 months prior and 6 months after the index date, and had no CDI diagnosis 84 days prior to the index date. The CDI episode on the index date was defined as the primary episode. CDI diagnoses occurring between 14 and 84 days after the primary episode were classified as recurrences. Three cohorts were constructed for two comparisons: patients without CDI matched by propensity score to those with primary CDI only and patients with primary CDI only matched to those with one recurrence (CDI+1). We identified 56,646 CDI patients with an average age of 61.0 years, 24.6% of whom had a recurrence within 84 days after primary CDI. Matched primary CDI only patients (41,205) and controls (123,615) averaged 8.4 and 2.5 days of hospitalization respectively, and cost $41,820 and $17,925 during the 180-day follow-up. Matched CDI+1 patients and their controls (primary CDI only) averaged 10.0 and 8.2 days respectively, with costs of $52,448 and $41,654. The attributable hospitalization for primary and recurrent CDI was 5.9 and 1.8 days, respectively and the attributable cost was $23,895 and $10,834, respectively, during the 180-day follow-up. The HCRU and economic burden associated with CDI are quite high.