Validity and Reliability of the Self-Care in MyeloProliferative Neoplasms Inventory (SC-MPNI)

ObjectiveThis study aimed to develop and psychometrically test a self-report questionnaire for measuring self-care behaviors in patients with myeloproliferative neoplasms (MPNs): the Self-Care in MyeloProliferative Neoplasms Inventory (SC-MPNI).MethodsA cross-sectional validation study was conducted in 9 Italian hematology centers from November 2021 to January 2024. Adult patients with myelofibrosis (MF), polycythemia vera (PV), and essential thrombocythemia (ET) were asked to complete a paper-and-pencil questionnaire during their outpatient visit or at home. The SC-MPNI was developed according to the Middle-Range Theory of Self-Care of Chronic Illness. This 30-item questionnaire includes three scales: self-care maintenance, self-care monitoring, and self-care management. The construct validity was tested using confirmatory factor analysis (CFA). The reliability of each scale was evaluated using McDonald's Omega composite reliability.ResultsOverall, 285 patients with MPNs (53% male; mean age = 60 years +/- 13) were included. They were diagnosed with MF (43%), PV (29%), or ET (28%). The self-care maintenance scale (13 items and 3 factors: adherence, healthy lifestyle, and prevention) fit well when tested with a three-factor model, and its reliability was 0.87. The self-care monitoring scale (9 items and 2 factors: symptom monitoring and parameter and test monitoring) fit well when tested with a two-factor model, and its reliability was 0.85. The self-care management scale (8 items and 2 factors: provider-directed behaviors and spontaneous behaviors) fit well when tested with a two-factor model, and its reliability was 0.79.ConclusionThe SC-MPNI is a valid and reliable self-report instrument to measure self-care behaviors in people living with MPNs.