validation of the Italian version of the MAINZ pain staging system - MPSS

BACKGROUND Prediction of outcome and risks for poor prognosis may allow pain patients and professionals to formulate reasonable management plan of Chronic Pain (CP). (1) The Mainz Pain Staging System (MPSS) is a German 3- categories interview-administered, multidimensional staging tool of pain chronicity. (2) AIMS To validate the Italian version of MPSS (I-MPSS) and to look for associations between the Brief Pain Inventory (BPI) scores and the I-MPSS categories. METHODS Following informed consent, I-MPSS and BPI were administered to n=120 consecutive non-cancer-pain patients (age>18 years; SPMSQ score < 2) upon their first pain-centre visit. Content validity was examine through literature review and experts judgment, factorial analysis and scree test; construct validity by comparison with BPI; and reliability, by Cronbach's alfa test. Measures were patients' demographics, I-MPSS stage and BPI scores. RESULTS I-MPSS category proportions (Fig. 1) were: I, 34.2%, II, 46.7% and III, 19.2%. I-MPSS showed 4 dimensions (Fig. 2.); Cronbach's alfa was > 0.8. Significant associations were found between I-MPSS I-II categories and BPI pain-intensity items and between I-MPSS III and BPI QoL items‘ scores (Fig. 3.). CONCLUSIONS The validated I-MPSS enabled the classification of mixed CP population in three categories showing associations with the BPI item scores. This tool may help Health System organizations to construct an I-MPSS-category-based pain-treatment paths and as predictor of CP prognosis it may have implications for public health initiatives. Results need confirmation with follow-up studies. Bibliography 1. Ostelo RW et al. Clinically important outcomes in low back pain. Best.Pract.Res.Clin.Rheumatol. 2005;19(4):593-607. 2. Pfingsten, M et al. Classification of chronic pain. Quantification and grading with the Mainz Pain Staging System. Schmerz. 2000;14(1):10-17.