[Development of a physical performance scale for patients with implanted pacemakers].
The development and the validation of the Pavia Physical Performance Scale (PPPS) is here presented. PPPS is a new instrument evaluating the physical performance of pacemaker implanted patients. Data comes from a cross-over clinical trial on the efficacy of two functions of the pacemaker device. Primary end-point is the improvement of the physical performance together with the quality of life. We used data of 168 patients actually enrolled and interviewed with the Pavia Physical Performance Scale. We first selected 30 Likert-type items; then we applied a statistical methodology of Homogeneity Analysis (HOMALS). We verified the homogeneity of the scale and the internal consistency (Cronbach's alpha = 0.92). With the same methodology, we developed the final version of PPPS. The final version lists 20 items; based on the results of the psychometric analysis, we turned the Likert-type scoring into a binary scoring (1 = no limitation of physical activity, 0 = limitation or never tried). The external validity, trough an Analysis of Variance of PPPS mean scores within New York Heart Association classes (NYHA), has been performed. We found a negative linear trend of PPPS scores and NYHA classes. That means an association between high PPPS scores (good physical performance) and low NYHA classes (also good physical capacity). The Pavia Physical Performance Scale (PPPS) could be proposed as a valid and consistent scale aimed to evaluate physical performance in pacemaker implanted patients. We suggest to use it in the clinical practice in addition to more traditional techniques.