Patient Dignity Inventory (PDI) Questionnaire: The Validation Study in Italian Patients with Solid and Hematological Cancers on Active Oncological Treatments

Abstract

Backgrounds In Oncology, little is known about dignity-related distress and the issues that influence the sense of dignity for patients. We validated the Patient Dignity Inventory (PDI) questionnaire in Italian patients on oncological active treatments. Methods After the translation procedures, the PDI was administered to 266 patients along with other questionnaires to assess the psychometric properties of the Italian version of PDI. Factor structure was tested by both explorative and confirmatory factor analyses. Concurrent validity was tested through convergent and divergent validity with validated questionnaires inquiring about physical and psychological symptoms, and religiosity. The test/retest reliability was assessed through the concordance coefficient of Linn (two-week interval, 80 patients). Results The explorative analysis suggested one factor only loading highly on all the 25 items (>.45) and explaining the 48% variance; confirmative analysis and Cronbach alpha (0.96) confirmed the adequacy of the one-factor model. In the 2-week test-retest study, a concordance coefficient of 0.73 (95% CI, 0.64–0.83) was found. High correlations of problems with dignity were found with both physical and psychological symptoms (0.52 and 0.64 rho coefficient, respectively), and a moderate inverse correlation with spiritual well being (-.40). The dignity construct, as measured by PDI, proved to be orthogonal to that of religiosity (-.02). Conclusions The Italian version of PDI is a valid and reliable tool to evaluate the dignity related-distress in out-patients with solid and hematological cancers, on active oncological treatments, in non advanced stages of the disease.