Risk Factors, Clinical Characteristics, and Treatment Differences Between Residents With and Without Nursing Home- and Non-Nursing Home-Acquired Clostridium difficile Infection.

BACKGROUND The incidence of Clostridium difficile infection (CDI) in nursing home residents is believed to be high because of the prevalence of predisposing factors such as decreased immune response, multiple comorbidities, medications, increased risk of infection, close proximity of residents, and recent hospitalization. Yet, specific information on CDI in this population is scarce.  OBJECTIVES To investigate differences in clinical and demographic characteristics, treatment, and underlying comorbidities in residents who acquired CDI preadmission (non-nursing home-acquired [NNH-Acquired]) compared with those who acquired CDI after admission to a nursing home (nursing home-acquired [NH-Acquired]) and matched controls. METHODS We conducted a retrospective case-control study of CDI in nursing home residents with a cross-sectional and longitudinal aspect of linked and de-identified pharmacy claims and Minimum Data Set data (MDS) 2.0 records from October 1, 2009, to September 30, 2010. The control group was frequency matched 1:1 for gender, race, and age range to residents with CDI.  RESULTS Of 195,498 residents, 5,044 (2.6%) had a diagnosis of CDI. Compared with controls, CDI patients had less severe cognitive impairment (P  less than  0.01) and more severe functional impairment (P  less than  0.01), incontinence (P  less than  0.01), and diarrhea (P  less than  0.01). They were more likely to (a) have diabetes, stroke, heart failure, cancer, renal failure, and infections; (b) be treated with antibiotics, corticosteroids, megestrol, and proton pump inhibitors; and (c) be discharged to the hospital (29.3% vs. 14.7%, P = 0.001) than controls. NNH-Acquired CDI was 3 times more prevalent than NH-Acquired CDI. Most residents with NNH-Acquired CDI (85.0%) came from acute care hospitals and were more likely to have heart disease, cancer, and infections, while those with NH-Acquired CDI tended to have more cognitive impairment, reliance on staff for activities of daily living, incontinence, and stroke. Thirty-day retreatment rates for NH-Acquired CDI and NNH-Acquired CDI with metronidazole were 72.7% and 68.4%, and with vancomycin were 83.9% and 69.3%, respectively. The facility (Medicare Part A) was the payer for 93.6% of NNH-Acquired CDI and 75% of NH-Acquired CDI treatment; Medicare Part D was the prevalent secondary payer for NNH-Aquired CDI (19.4%) and NH-Acquired CDI (37.5%). CONCLUSIONS Residents with CDI had more comorbidities, and the NNH-Acquired group bore a higher burden of illness, resulting in differing treatment patterns and outcomes than the NH-Acquired CDI group.