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Index: Ostomy Wound Manage. 2012;58(2):34–40.

Abstract

  The validity and reliability of the Braden Scale for pressure ulcer development has been established in a variety of patient care settings, but studies suggest the scale does not capture risk factors in surgical patients. The purpose of this meta-analysis was to assess the predictive validity of the Braden Scale for pressure ulcer development in surgical patients. A literature search using PubMed and Web of Science databases (through July 2011) was conducted to identify all clinical studies on predicting pressure ulcers in surgical patients using the Braden Scale. To be eligible for inclusion, studies had to include sensitivity (true positive rate, TPR) and specificity (true negative rate, TNR) results or include sufficient data to calculate these factors. Study quality was assessed using the 14-item Quality Assessment of Diagnostic Accuracy Studies (QUADAS) instrument, and two-by-two tables of predictive validity were constructed from each article. Meta-analysis for predictive validity was performed, including calculation of pooled sensitivity, pooled specificity, diagnostic odds ratio (DOR), construction of summary receiver operating characteristic (SROC) curves, and overall diagnostic accuracy (Q*). Three studies (N = 609 patients) met the meta-analysis inclusion criteria. The pooled estimates for sensitivity and specificity were 0.42 (95% CI: 0.38 to 0.47) and 0.84 (95% CI: 0. 83 to 0.85), respectively, yielding a combined DOR of 4.40 (95% CI: 2.98 to 6.50). The area under the ROC curve (AUC) was 0.6921 ± 0.0346, and the Q* was 0.6466 ± 0.0274. Significant heterogeneity was noted between the included studies with Q value 34.49 (P = 0.0321), and I² for pooled sensitivity, pooled specificity, and pooled DOR was 88.7%, 98.6%, and 39.1%, respectively. Although the observed heterogeneity between studies may have affected the results, the low values for overall diagnostic accuracy (Q*) and diagnostic capability (AUC) indicate the Braden Scale has low predictive validity for pressure ulcer risk in surgical patients. A new pressure ulcer risk assessment scale for surgical patients should be developed and tested.

Keywords: pressure ulcer, surgical patients, Braden Scale, predictive validity, meta-analysis

Potential Conflicts of Interest: none disclosed

Introduction

  The patient who undergoes a long, complicated surgery is potentially at risk for developing pressure ulcers. Results of a nationwide survey¹ in the US showed an overall pressure ulcer incidence for surgical patients of 8.5% (95% confidence interval: 6.1% to 10.9%). The situation is similar in other countries, with prevalence rates ranging from 14.3% to 21.2%.^2,3 The most common procedures complicated by pressure ulcers are cardiac, general/thoracic, orthopedic, and vascular surgery.¹

  Pressure ulcers are painful, prolong patient hospital stay, and may generate significant additional costs.^4,5 The first step in the pressure ulcer prevention process is risk assessment to identify both the patients who require preventive measures and the specific factors that put them at risk. The most widely used risk assessment scales are the Braden Scale, the Norton Scale, and the Waterlow Scale.^6,7 A systematic review⁶ indicated that the Braden Scale offers the best balance between sensitivity and specificity and the best risk estimate and that the Braden Scale is more accurate than nurses’ clinical judgment in predicting pressure ulcer risk.

  The Braden Scale evaluates the risk of skin breakdown in six domains: sensory perception, moisture, activity, mobility, nutrition, and friction and shear.