The effect of hospital-acquired infection with Clostridium difficile on length of stay in hospital is not yet fully understood. Alan J. Forster, of the Clinical Epidemiology Program at Ottawa Hospital Research Institute, and colleagues, determined the independent impact of hospital-acquired infection with C. difficile on length of stay in hospital.
The researchers conducted a retrospective observational cohort study of admissions to hospital between July 1, 2002, and Mar. 31, 2009, at a single academic hospital. They measured the association between infection with hospital-acquired C. difficile and time to discharge from hospital using Kaplan-Meier methods and a Cox multivariable proportional hazards regression model. They controlled for baseline risk of death and accounted for C. difficile as a time-varying effect.
Hospital-acquired infection with C. difficile was identified in 1,393 of 136 877 admissions to hospital (overall risk 1.02%, 95% confidence interval [CI] 0.97%1.06%). The crude median length of stay in hospital was greater for patients with hospital-acquired C. difficile (34 d) than for those without C. difficile (8 d). Survival analysis showed that hospital-acquired infection with C. difficile increased the median length of stay in hospital by six days. In adjusted analyses, hospital-acquired C. difficile was significantly associated with time to discharge, modified by baseline risk of death and time to acquisition of C. difficile. The hazard ratio for discharge by day 7 among patients with hospital-acquired C. difficile was 0.55 (95% CI 0.390.70) for patients in the lowest decile of baseline risk of death and 0.45 (95% CI 0.320.58) for those in the highest decile; for discharge by day 28, the corresponding hazard ratios were 0.74 (95% CI 0.600.87) and 0.61 (95% CI 0.530.68).
The researchers concluded that hospital-acquired infection with C. difficile significantly prolonged length of stay in hospital independent of baseline risk of death. Their research was published in the Canadian Medical Association Journal.
Reference: Forster AJ, Taljaard M, Oake N, Wilson K, Roth V and van Walrave C. The effect of hospital-acquired infection with Clostridium difficile on length of stay in hospital. CMAJ Dec. 5, 2011. doi: 10.1503/cmaj.110543