Development and initial validation of a questionnaire to assess patients’ perception of protective isolation following haematopoietic stem cell transplantation

The aim of this study was to develop and psychometrically test a questionnaire assessing patients' perception of protective isolation following haematopoietic stem cell transplantation (HSCT). The conceptual framework for developing the questionnaire was a three-dimensional model that emerged from a metasynthesis: isolation-related suffering, relationship with oneself and relationship with others. Item selection was performed through a focus group, comparison with the findings of two phenomenological studies, and content validity with 22 experts. Cognitive interviews with five patients were used to verify face validity. A validation study was conducted in 10 Italian centres, all members of the Italian Group of stem cell transplant (GITMO). Patients completed the questionnaires between 7 and 9 days post-transplant. Dimensionality was tested through exploratory factor analysis (EFA). A total of 17 items yielded a content validity index (CVI) of 0.88. Participants included 186 adult patients receiving autologous (48%) or allogeneic (52%) HSCT in protective isolation. The EFA yielded a three-factor solution, explaining 55% of the variance. The scale showed adequate psychometric properties, with the exception of three items, which were eliminated. Future studies should test the psychometric properties of the questionnaire through confirmatory factor analysis and verify its transcultural validity.