The Norton, Waterlow, Braden, and care dependency scales: Comparing their validity when identifying patients' pressure sore risk

OBJECTIVES: We compared the sensitivity and specificity of the Norton, Waterlow, and Braden Scales in identifying patients at pressure sore risk. An additional goal was to determine whether or not the Care Dependency Scale (CDS) is able to detect patients at risk for pressure sore development. METHODS: The investigation was part of a prevalence study involving 754 patients in 3 Berlin hospitals. A questionnaire was used containing the subscales of the 3 risk calculators (Norton, Waterlow, and Braden), and the CDS. On the specified day nurses filled in the questionnaire using data obtained from the patients' charts and direct visualization of the patients' skin. RESULTS: Thirty-four out of 754 patients had at least 1 pressure ulcer. Comparing the 3 risk assessment tools, the Waterlow scale demonstrated the highest sensitivity (0.86) and the Norton scale demonstrated the highest specificity (0.75). Individuals with pressure sores were more likely to be care dependent (t-test: P< .01); 27 of them had a CDS score lower than 55. Using the score of 55 as the cut-off point, the CDS demonstrated a sensitivity of 0.74 and a specificity of 0.83. SUMMARY: This study demonstrated remarkable differences among the 3 commonly used risk assessment tools, in regards to sensitivity and specificity. Moreover, the CDS seems to have a diagnostic value similar to the 3 commonly used risk assessment calculators.