Validation of a Modified Version of the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score

Patients with myeloproliferative neoplasms (MPNs) suffer from chronic and progressive symptom burden. MPN trials capturing patient-reported symptoms routinely administer the MPN Symptom Assessment Form (SAF). The MPN-10 assesses 10 of the most clinically relevant symptoms, including fatigue and generates a Total Symptom Score (TSS). The original MPN-10 included a fatigue item from the Brief Fatigue Inventory (BFI). The myelofibrosis-specific symptom assessment tool called the MFSAF v4 utilizes a fatigue item developed to be consistent with other items within the SAF. This study sought to validate a modified version of the MPN-10 TSS using the SAF fatigue item for harmonization with MFSAF v4.Survey data from two cohorts of patients with essential thrombocythemia, polycythemia vera, or myelofibrosis assessing MPN characteristics and symptom burden were used.BFI and SAF fatigue items were highly correlated in raw score (Pearson r = 0.88), comparable in their severity categorizations (89% agreement for severe versus non-severe) and respective contributions to the TSS (both Cronbach's alpha = 0.89). Reliability of SAF fatigue was acceptable and independently associated with known disease-related characteristics (splenomegaly, low quality-of-life, and distress). Fatigue in patients with MPNs is measured with high similarity using the SAF fatigue item within the MPN-10 in harmonization with the MFSAF v4.