Impact of nosocomial infection on length of stay and functional improvement among patients admitted to an acute rehabilitation unit

Abstract

Objective: To identify factors predictive of length of stay (LOS) and the level of functional improvement achieved among patients admitted to an acute rehabilitation unit for the first time, with special reference to the role of nosocomial infection.

Setting: A 40-bed acute rehabilitation unit within a 300-bed, tertiary-care, public, university-affiliated hospital.

Study population: All patients admitted to the unit between January 1997 and July 1998.

Design: Prospective cohort study in which demographic and clinical data, including occurrence of nosocomial infection, were collected during the entire unit admission of each patient. Multivariate linear regression analysis was used to identify factors predictive of unit LOS or improvement in functional status as measured by the change in the Functional Independence Measure (FIM) score between admission and discharge (deltaFIM).

Results: There were 423 admissions to the rehabilitation unit during the study period, of which 91 (21.5%) had spinal cord injury (SCI) as a principal diagnosis. One hundred seven nosocomial infections occurred during 84 (19.9%) of the 423 admissions. The most common infections were urinary tract (31.8% of all infections), surgical-site (18.5%), and Clostridium difficile diarrhea (15%). Only one patient died of infection. After controlling for severity of illness on admission, functional status on admission, age, and other clinical factors, the significant positive predictors of unit LOS were as follows: SCI (P<.001), pressure ulcer (.002), and nosocomial infection (<.001). Significant negative predictors of deltaFIM were age (P<.001), FIM score on admission (<.001), prior hospital LOS (.002), and nosocomial infection (.007).

Conclusions: Several variables were identified as contributing to a longer LOS or to a smaller improvement in functional status among patients admitted for the first time to an acute rehabilitation unit. Of these variables, only nosocomial infection has the potential for modification. Studies of new approaches to prevent infections among patients undergoing acute rehabilitation should be pursued.