Patient (pt) interview–based content validation of the Myelofibrosis Symptom Assessment Form version 4.0 (MFSAF v4.0).

Abstract

e23106 Background: Pts with myelofibrosis (MF) often experience debilitating symptoms that negatively impact health-related quality of life and functioning. The MFSAF v4.0 is a 7-item questionnaire assessing the burden of MF symptoms, including fatigue, night sweats, pruritus, abdominal discomfort, pain under left ribs, early satiety, and bone pain. Each item is evaluated on an 11-point numeric rating scale (NRS) from 0 (absent) to 10 (worst imaginable). We sought to evaluate the content validity of the MFSAF v4.0 in Janus kinase inhibitor–experienced pts with MF. Methods: Qualitative interviews were conducted remotely by trained interviewers with 20 Janus kinase inhibitor–experienced and symptomatic (MFSAF Total Symptom Score [TSS] ≥10) pts with MF from the US (n = 5) and UK, Germany, Italy, Poland, and Spain (n = 3 each). The interview began with a concept elicitation section to allow spontaneous reporting of important concepts prior to content validation of the MFSAF v4.0 items and NRS as relevant, important, and understandable to pts. Results: Mean pt age was 59.4 years; 50% were male, 55% were diagnosed within the past year, 95% were on any treatment for MF, and 75% were anemic. On average, pts had 2.1 transfusions within the past 3 mo. Mean MFSAF v4.0 TSS was 28.6.The top spontaneously endorsed symptoms were tired (70%), bone/muscle pain (70%), fatigue (55%), night sweats (45%), and pruritis (45%), many of which are also items in the MFSAF v4.0. An additional 18 symptoms were spontaneously mentioned by pts prior to completion of the MFSAF v4.0. Many of these other symptoms were endorsed by ≤10% of pts (1 or 2 pts each), and 90% of pts felt that the measure represented their experience and did not recommend inclusion of additional symptoms after reviewing the measure. Overall, pts showed a clear understanding of the MFSAF v4.0 (Table). No more than 3 pts (15%) mentioned that a given item was not relevant to their individual experience. Pts consistently felt that it was easy to select an answer on the response scale and were able to differentiate response options. When describing meaningful change in terms of NRS, pts most often suggested that an improvement of 2 to 4 points would be meaningful. Conclusions: Based on the findings from this study, the MFSAF v4.0 is a content-valid measure for pts with MF and captures the most important concepts. All items are comprehensible and relevant, with the NRS endorsed as an appropriate response scale. [Table: see text]