Extrinsic risk factors for pressure ulcers early in the hospital stay: a nested case-control study

Little is known about the impact of extrinsic factors on pressure ulcer risk. The objective of this study was to determine whether risk of pressure ulcers early in the hospital stay is associated with extrinsic factors such as longer emergency department (ED) stays, night or weekend admission, potentially immobilizing procedures and medications, and admission to an intensive care unit (ICU).

A nested case-control study was performed in two teaching hospitals in Philadelphia, Pennsylvania. Participants were medical patients age > or =65 years admitted through the ED. Cases (n = 195) had > or =1 possibly or definitely hospital-acquired pressure ulcers. Three controls per case were sampled randomly from among noncases at the same hospital in the same month (n = 597). Pressure ulcer status was determined by a research nurse on the third day of hospitalization. Pressure ulcers were classified as preexisting, possibly hospital-acquired, or definitely hospital-acquired. Information on extrinsic factors was obtained by chart review.

The odds of pressure ulcers were twice as high for those with an ICU stay as for those without (adjusted odds ratio [aOR] 2.0, 95% confidence interval [CI], 1.2-3.5). The aOR was 0.6 (95% CI, 0.3-0.9) for use of any potentially immobilizing medications during the early inpatient period.

Many of the procedures experienced by patients in the ED and early in the inpatient stay do not confer excess pressure ulcer risk. Having an ICU stay is associated with a doubling of risk. This finding emphasizes the importance of developing and evaluating interventions to prevent pressure ulcers among patients in the ICU.