Myelofibrosis Symptom Assessment Tool Demonstrates Strong Validity and Reliability in Trials

The Myelofibrosis Symptom Assessment Form Total Symptom Score version 4.0 (MFSAF TSS v4.0) reliably captures the symptom experience of patients with myelofibrosis (MF) and effectively differentiates changes over time, supporting its role as a clinically meaningful end point in future MF therapeutic trials, according to a study published in Quality of Life Research.

“The Myelofibrosis Symptom Assessment Form Total Symptom Score version 4.0 (MFSAF TSS v4.0) is a questionnaire that asks patients to report the severity of seven symptoms (tiredness, night sweats, itching, stomach pain, pain under the left ribs, getting full quickly, bone pain) on a 0 (absent) to 10 (worst imaginable) rating scale,” authors explained.

Among the 195 intent-to-treat patients, completion rates remained high across all time points (≥92.2%), and baseline symptom burden was notable (mean TSS: 27.2). Confirmatory factor analysis supported a unidimensional structure, and item-to-total correlations were consistently above 0.5, with internal consistency reliability values of α = 0.877 at baseline and α = 0.903 at week 24. Test-retest reliability was excellent in stable patients (intraclass correlation coefficient [ICC], 0.911 for patient global impression of severity-fatigue [PGIS-F]), further confirming reproducibility.

Construct validity was demonstrated through moderate to strong correlations with related patient-reported outcomes, particularly the European Organization for Research and Treatment of Cancer QLQ-C30 (EORTC QLQ-C30) pain and EuroQoL 5D-5L (EQ-5D-5L) pain/discomfort domains. Known-groups validity showed that MFSAF TSS scores significantly discriminated between patients based on PGIS and Eastern Cooperative Oncology Group performance status (ECOG) performance status, with mean TSS scores increasing with greater symptom severity. Sensitivity-to-change analyses revealed significantly larger symptom improvements in patients reporting clinical benefit, with effect sizes ranging from moderate to large (0.69–1.16).

“The analyses described here provide preliminary evidence that the MFSAF TSS v4.0 is an appropriate instrument for clinical trial endpoint use in patients with JAK inhibitor–experienced MF who are anemic and symptomatic,” concluded the study authors.

Reference

Daskalopoulou C, Gorsh B, Dumi G, et al. Myelofibrosis symptom assessment form total symptom score version 4.0: measurement properties from the MOMENTUM phase 3 study. Qual Life Res. 2025;34(3):739-750. doi:10.1007/s11136-024-03855-1