Development of a Tool for Pressure Ulcer Risk Assessment and Preventive Interventions in Ancillary Services Patients Monica S. Messer Abstract The incidence of nosocomial pressure ulcers has increased 70 percent in U.S. hospitals over the past 15 years despite implementation of preventive guidelines and the wide-spread use of validated risk assessment tools. Most preventive efforts have been focused primarily on patients who are bed-ridden or immobile for extended periods. What has not been well studied or identified is the risk for pressure injury to patients undergoing diagnostic procedures in hospital ancillary units where extrinsic risk factors such as high interface pressures on procedure tables and friction and shear from positioning and transport can greatly magnify the effect of patient-specific intrinsic risk factors which might not otherwise put these patients at high risk on an inpatient unit. The purpose of this study was to develop a risk assessment tool designed explicitly to quantify the combination of these intrinsic and extrinsic risk factors in individual patients undergoing ancillary services procedures, and to identify targeted preventive interventions based on the individual level of risk. Empirically and theoretically-derived risk factors for the tool were tested in a nation-wide hospital database of over 6 million patient discharge records using bivariate and multivariate analysis to identify significant predictors of pressure ulcer outcomes. The statistically significant factors emerging were then used to develop the risk assessment scale. These predictors included; advanced age, diabetes, human immunodeficiency virus infection, sepsis, and fever. The scale was tested for internal validity using the split-sample cross-validation method, and for accuracy using the area under the Receiver Operating Characteristics curve. The optimum score cut point was identified to provide a predictive accuracy of 71 percent. Interventions for the tool were identified from national clinical practice guidelines and aligned in sets based on patient levels of risk identified by the scoring portion of the tool. The entire tool was evaluated for content validity by a panel of five international nurse experts in pressure ulcer prevention and tool development. The content validity index calculated from their ratings was .91 indicating excellent agreement on content validity.