To determine the risk factors for Clostridium difficile–associated disease (CDAD) in a 25-bed rural hospital and to compare antimicrobial use ratios at the study hospital with those at a large academic medical center.
A 25-bed rural hospital in Iowa during the period from August 2002 through January 2005.
A total of 17 case patients with CDAD and 34 control patients matched for age (ie, within 10 years of the case patient's age), sex, and admission date (ie, within 2 weeks of the case patient's admission date).
Retrospective medical record review was performed to obtain data on antimicrobial exposures during the 6 weeks before hospital admission for both case and control patients. Exact conditional logistic regression was used for univariable and multivariable analyses. Antimicrobial use ratios were calculated to compare the rates of antimicrobial use for case and control patients at the study hospital with the rates for patients evaluated in a study of CDAD at a nearly 700-bed teaching hospital.
Case patients had a larger cumulative number of days of antimicrobial use (P = .004), and they received a larger total number of antimicrobial agents during hospitalization (P = .001). Antimicrobial use ratios were higher for both case and control patients at the smaller hospital, compared with the larger hospital.
CDAD at a small rural hospital was not associated with exposure to the antimicrobial classes that are typically associated with CDAD, but was instead related to the total number of antimicrobials used to treat patients. The rate of antimicrobial use for case and control patients was about 40% higher at the small rural hospital, compared with the corresponding rates at a large academic medical center.