Prospective cohort study of routine use of risk assessment scales for prediction of pressure ulcers

Objective To evaluate whether risk assessment scalescan be used to identify patients who are likely to getpressure ulcers.Design Prospective cohort study.Setting Two large hospitals in the Netherlands.Participants 1229 patients admitted to the surgical,internal, neurological, or geriatric wards betweenJanuary 1999 and June 2000.Main outcome measure Occurrence of a pressureulcer of grade 2 or worse while in hospital.Results 135 patients developed pressure ulcersduring four weeks after admission. The weeklyincidence of patients with pressure ulcers was 6.2%(95% confidence interval 5.2% to 7.2%). The areaunder the receiver operating characteristic curve was0.56 (0.51 to 0.61) for the Norton scale, 0.55 (0.49 to0.60) for the Braden scale, and 0.61 (0.56 to 0.66) forthe Waterlow scale; the areas for the subpopulation,excluding patients who received preventive measureswithout developing pressure ulcers and excludingsurgical patients, were 0.71 (0.65 to 0.77), 0.71 (0.64 to0.78), and 0.68 (0.61 to 0.74), respectively. In thissubpopulation, using the recommended cut­off points,the positive predictive value was 7.0% for the Norton,7.8% for the Braden, and 5.3% for the Waterlow scale.Conclusion Although risk assessment scales predictthe occurrence of pressure ulcers to some extent,routine use of these scales leads to inefficient use ofpreventive measures. An accurate risk assessmentscale based on prospectively gathered data should bedeveloped.