Mortality, Hospital Costs, Payments, and Readmissions Associated With Clostridium difficile Infection Among Medicare Beneficiaries

BACKGROUND The management of Clostridium difficile infection (CDI) among hospitalized patients is costly, and ongoing payment reform is compelling hospitals to reduce its burden. To assess the impact of CDI on mortality, hospital costs, healthcare use, and Medicare payments for beneficiaries who were discharged with CDI listed as a secondary International Classification of Diseases, Ninth Revision, Clinical Modification claim diagnosis. METHODS Data were analyzed from the 2009 to 2010 5% random sample Medicare Standard Analytic Files of beneficiary claims. Patients with index hospitalizations with CDI as a secondary diagnosis and no previous hospitalization within 30 days were identified. Outcomes included inpatient and 30-day mortality, inpatient costs, index hospital payments, all-provider payments, net hospital losses, payment to cost ratio, length of stay (LOS), and 30-day readmission; outcomes were each risk adjusted using propensity score matching and regression modeling techniques. RESULTS A total of 3262 patients with CDI were identified after matching to patients without a CDI diagnosis. After risk adjustment, secondary CDI was associated with statistically significantly (all P < 0.05) greater inpatient mortality (3.1% vs. 1.7%), 30-day mortality (4.1% vs. 2.2%), longer LOS (7.0 days vs. 3.8 days), higher rates of 30-day hospital readmissions (14.8% vs. 10.4%), and greater hospital costs ($16,184 vs. $13,954) compared with the non-CDI cohort. The risk-adjusted payment-to-cost ratio was shown to be lower for patients with CDI than those without (0.76 vs. 0.85). CONCLUSIONS Secondary CDI is associated with greater adjusted mortality, costs, LOS, and hospital readmissions, while receiving similar hospital reimbursement compared with patients without CDI in a Medicare population.