OBJECTIVES: Essential Thrombocythemia (ET) is a rare condition that is a subtype of the myeloproliferative neoplasms (MPN) and is characterized by clonal blood cell proliferation and excessive production of platelets. ET patients experience severe symptoms compromising quality of life. A targeted literature review was undertaken to synthesize information on patient-reported outcomes (PRO) symptoms and impacts of ET to derive a conceptual framework and identify suitable PROs for use in the ET population.

METHODS: A review of published studies was conducted in the OVID databases, PROQOLID™, and gray literature. Eligible articles included ET-only populations and extended to MPN samples including ET. Limitations included restricting search results to the past 11 years, human research, and English language.

RESULTS: Of the 890 abstracts reviewed for eligibility, 238 were included in the analysis. The ET conceptual model encompasses disease-defining concepts (10 symptoms, fatigue most prevalent); proximal disease impacts (physical functioning, fatigue impacts, etc); distal impacts (emotional, cognitive); and distal/general life impacts (financial, relationships, etc). Of the 238 papers reviewed, the MFSAF v4.0 or predecessors (n=180), EORTC QLQ-C30 (n=46), PROMIS-Fatigue (n=4), and Brief Fatigue Inventory (n=3; BFI) were most frequently used in the papers to measure symptoms and impacts of ET. Mapping those 4 PROs with the ET conceptual model revealed the MFSAF 4.0 covers 5 disease defining concepts of ET including fatigue, pain, early satiety, night sweats, and abdominal discomfort. The PROMIS-Fatigue and BFI only cover fatigue and impact of fatigue concepts while the EORTC QLQ-C30 covers some disease concepts in addition to proximal and distal disease impacts and impacts on general life.

CONCLUSIONS: This review highlights symptoms and impacts among patients with ET and reveals that there are options for patient-reported measures for use in the ET population.