Risk assessment scales for pressure ulcers: a theoretical, methodological, and clinical perspective

Several instruments have been devised to measure risk of developing pressure ulcers. In this article, the value of risk assessment scales is explored and discussed from a theoretical, methodological, and clinical perspective. The first part of the article focuses on the validity of such scales from the first two perspectives. It is argued that currently it is not possible to devise an instrument with perfect content validity because too many factors are involved in the development of pressure ulcers. When establishing predictive validity of a risk assessment instrument, one needs an external criterion to test sensitivity and specificity. This article argues that the external criterion normally used--pressure ulcers that actually develop--is not a good indicator of the risk of developing pressure ulcers, because this criterion is influenced by the use of preventive methods. Therefore, the author suggests using not only the pressure ulcers that actually develop, but also incorporating preventive methods into the external criterion. Despite their limitations, risk assessment scales are recommended. However, to be effective, they should be used within a broader preventive program. Furthermore, using the chance a patient has of developing pressure ulcers, instead of one or two cutoff points, is recommended.