Symptomatic burden in myeloproliferative
neoplasms is present in most patients and compromises quality of life. We sought to validate a broadly applicable 18-item instrument (Myeloproliferative
Neoplasm Symptom Assessment Form [MPN-
SAF], coadministered with the Brief
Fatigue Inventory) to assess symptoms of
myelofibrosis,
essential thrombocythemia, and
polycythemia vera among prospective cohorts in the United States, Sweden, and Italy. A total of 402 MPN-
SAF surveys were administered (English [25%], Italian [46%], and Swedish [28%]) in 161 patients with
essential thrombocythemia, 145 patients with
polycythemia vera, and 96 patients with
myelofibrosis. Responses among the 3 administered languages showed great consistency after controlling for MPN subtype. Strong correlations existed between individual items and key symptomatic elements represented on both the MPN-
SAF and the European Organisation for Research and Treatment of
Cancer Quality of Life Questionnaire-C30. Enrolling physicians' blinded opinion of patient symptoms (6 symptoms assessed) were highly correlated with corresponding patients' responses. Serial administration of the English MPN-
SAF among 53 patients showed that most MPN-
SAF items are well correlated (r > 0.5, P < .001) and highly reproducible (intraclass correlation coefficient > 0.7). The MPN-
SAF is a comprehensive and reliable instrument that is available in multiple languages to evaluate symptoms associated with all types of MPNs in clinical trials globally.