Papers

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

Lisette Schoonhoven, PhD student, ^a Jeen R E Haalboom, associate professor of medicine, ^b Mente T Bousema, dermatologist, ^c Ale Algra, associate professor of clinical epidemiology, ^a Diederick E Grobbee, professor of clinical epidemiology, ^a Maria H Grypdonck, professor of nursing sciences, ^a Erik Buskens, assistant professor of medical technology assessment, ^a for the prePURSE study group.

^a Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, PO Box 85500, 3508 GA, Utrecht, Netherlands, ^b Department of Internal Medicine, University Medical Centre Utrecht, ^c Department of Dermatology, Eemland Hospital, PO Box 1502, 3800 BM, Amersfoort, Netherlands

Correspondence to: L Schoonhoven L.Schoonhoven{at}jc.azu.nl

Objective: To evaluate whether risk assessment scales can be used to identify patients who are likely to get pressure ulcers.
Design: Prospective cohort study.
Setting: Two large hospitals in the Netherlands.
Participants: 1229 patients admitted to the surgical, internal, neurological, or geriatric wards between January 1999 and June 2000.
Main outcome measure: Occurrence of a pressure ulcer of grade 2 or worse while in hospital.
Results: 135 patients developed pressure ulcers during four weeks after admission. The weekly incidence of patients with pressure ulcers was 6.2% (95% confidence interval 5.2% to 7.2%). The area under the receiver operating characteristic curve was 0.56 (0.51 to 0.61) for the Norton scale, 0.55 (0.49 to 0.60) for the Braden scale, and 0.61 (0.56 to 0.66) for the Waterlow scale; the areas for the subpopulation, excluding patients who received preventive measures without developing pressure ulcers and excluding surgical patients, were 0.71 (0.65 to 0.77), 0.71 (0.64 to 0.78), and 0.68 (0.61 to 0.74), respectively. In this subpopulation, using the recommended cut-off 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 predict the occurrence of pressure ulcers to some extent, routine use of these scales leads to inefficient use of preventive measures. An accurate risk assessment scale based on prospectively gathered data should be developed.

What is already known on this topic The incidence of pressure ulcers in hospitalised patients varies between 2.7% and 29.5% Guidelines for prevention of pressure ulcers base the allocation of labour and resource intensive measures on the outcome of risk assessment scales Most risk assessment scales are based on expert opinion or literature review and have not been evaluated The sensitivity and specificity of risk assessment scales vary What this study adds The effectiveness of available risk assessment scales is limited Use of the outcome of risk assessment scales leads to inefficient allocation of preventive measures