The rationale for the use of risk calculators in pressure sore prevention, and the evidence of the reliability and validity of published scales.

Recent studies have shown an increase in pressure sore prevalence rates. However, methodological inconsistencies and demographic considerations, which include an ageing population, make it difficult to interpret and compare results. A multiplicity of intrinsic and extrinsic factors are thought to be associated with increased risk. The development of risk calculators which incorporate these factors has been an attempt to identify which subjects are most at risk so that equipment and nursing interventions can be allocated appropriately. Since the 1960s there has been a proliferation of risk assessment scales which have not been subjected to rigorous scrutiny of their reliability and validity, and this is held to represent a failure of nursing research. Recent evidence suggests that if critical cut-off points for 'at-risk' vs. 'no risk' are adjusted for particular patient populations the validity of existing scales can be improved. Missing from the literature are research reports of studies carried out in the community. As a result of demographic changes and community care policies, more 'at-risk' patients are likely to be nursed at home. Future research needs to include community studies, and a more systematic approach in general, to the study of the predictive value of existing scales.