Effect of Clostridium difficile Prevalence in Hospitals and Nursing Homes on Risk of Infection

Objectives: To assess the effect of facility Clostridium difficile infection (CDI) prevalence on risk of healthcare facility (HFC) acquired CDI. Design: Retrospective cohort study. Setting: Medicare fee-for-service (FFS) claims and skilled nursing facility (SNF) Minimum Data Set 3.0 assessments. Participants: Medicare beneficiaries with 90 days or more of no contact with a HCF before a hospital admission without a CDI diagnosis. Participants were separated into two cohorts: discharged to the community and discharged to a SNF. Measurements: Risk of HCF-acquired CDI associated with CDI prevalence at the index facility measured according to 30-day rehospitalization with a discharge diagnosis of CDI or diagnosis in the SNF after admission. Hospital and SNF CDI prevalence were categorized into three groups: 0% and above and below the median value for facilities with greater than 0% prevalence. Results: Of 817,900 eligible individuals, there were 553,423 admissions in the first cohort (discharged to the community) and 315,109 in the second (discharged to a SNF). In the first cohort, the risk of HCF-acquired CDI was higher for individuals admitted to hospitals with CDI prevalence less than the median (relative risk (RR) = 1.58, 95% confidence interval (CI) = 1.18–2.12) and greater than the median (RR = 2.56, 95% CI = 1.91–3.45) than for those with no CDI. In the second cohort, the risk of HCF-acquired CDI was greater for individuals admitted to a hospital (RR = 1.89, 95% CI = 1.49–2.39) and a SNF (RR = 1.48, 95% CI = 1.31–1.67) with CDI prevalence greater than the median. Conclusion: The risk of HCF-acquired CDI is greater for noninfected individuals admitted to hospitals and SNFs with a high prevalence of CDI.