Post-hospitalization Treatment Regimen and Readmission for C. difficile Colitis in Medicare Beneficiaries

C. difficile (CDI) has surpassed methicillin-resistant staph aureus as the most common nosocomial infection with recurrence reaching 30% and the elderly being disproportionately affected. We hypothesized that post-discharge antibiotic therapy for continued CDI treatment reduces readmissions.

We queried a 5% random sample of Medicare claims (2009-2011 Part A and Part D; n = 864,604) for hospitalizations with primary or secondary diagnosis of CDI. We compared demographics, comorbidities, and post-discharge CDI treatment (no CDI treatment, oral metronidazole only, oral vancomycin only, or both) between patients readmitted with a primary diagnosis of CDI within 90 days and patients not readmitted for any reason using univariate tests of association and multivariable models.

Of 7042 patients discharged alive, 945 were readmitted ≤90 days with CDI (13%), while 1953 were not readmitted for any reason (28%). Patients discharged on dual therapy had the highest rates of readmission (50%), followed by no post-discharge CDI treatment (43%), vancomycin only (28%), and metronidazole only (19%). Patients discharged on only metronidazole (OR 0.28) or only vancomycin (OR 0.42) had reduced odds of 90-day readmission compared to patients discharged on no CDI treatment. Patients discharged on dual therapy did not vary in odds of readmission.

Thirteen percent of patients discharged with CDI are readmitted within 90 days. Patients discharged with single-drug therapy for CDI had lower readmission rates compared to patients discharged on no ongoing CDI treatment suggesting that short-term monotherapy may be beneficial in inducing eradication and preventing relapse. Half of patients requiring dual therapy required readmission, suggesting patients with symptoms severe enough to warrant discharge on dual therapy may benefit from longer hospitalization.