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

Objective This 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). Methods A 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. Results Overall, 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. Conclusion The SC‐MPNI is a valid and reliable self‐report instrument to measure self‐care behaviors in people living with MPNs.