Psychometric properties of the PROMIS<sup>®</sup> Fatigue Short Form 7a among adults with myalgic encephalomyelitis/chronic fatigue syndrome. — CFSMEATLAS
Psychometric properties of the PROMIS® Fatigue Short Form 7a among adults with myalgic encephalomyelitis/chronic fatigue syndrome.
Yang, Manshu, Keller, San, Lin, Jin-Mann S · Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation · 2019 · DOI
Quick Summary
Researchers tested whether a short questionnaire called PROMIS Fatigue (7 questions) accurately measures fatigue in people with ME/CFS. They found that the questionnaire reliably captures how tired ME/CFS patients feel, works the same way for different ages and genders, and can detect when fatigue changes over time. This tool may help doctors and researchers measure whether new treatments for ME/CFS actually work.
Why It Matters
Having a validated, brief fatigue measurement tool is essential for ME/CFS clinical trials and treatment development. This study provides evidence that the PROMIS F-SF is reliable and responsive enough to measure whether experimental therapies actually reduce fatigue in ME/CFS patients, potentially accelerating the pace of drug development for this debilitating condition.
Observed Findings
ME/CFS patients had mean fatigue T-scores of 68.6, substantially higher than the general population mean of 50.
Fatigue scores showed a monotonic dose-response relationship with functional impairment severity (p < 0.01).
Internal consistency was good (Cronbach's α = 0.84) with minimal floor/ceiling effects.
Responsiveness to change over time was acceptable with small-to-medium effect sizes (Guyatt's Responsiveness Statistic = 0.28-0.54).
Inferred Conclusions
The PROMIS F-SF is a reliable and valid instrument for measuring fatigue severity in ME/CFS populations.
The tool shows acceptable sensitivity to detect changes in fatigue over time in ME/CFS patients.
The measure is suitable for use as a primary outcome in ME/CFS clinical trials to evaluate therapeutic efficacy.
The PROMIS F-SF warrants submission as a drug development tool for FDA qualification in ME/CFS studies.
Remaining Questions
How does the PROMIS F-SF correlate with objective biomarkers of ME/CFS severity (e.g., post-exertional malaise markers, exercise capacity)?.
What This Study Does Not Prove
This study validates a measurement tool but does not prove what causes ME/CFS fatigue or propose any treatments. It also does not establish whether improvements on this questionnaire correlate with changes in objective biomarkers or real-world functional capacity. The study's cross-sectional design and relatively small follow-up sample (n=386) limit causal inference.