Micaylon Moore, Hayden Keeler, Lauren Kocour, Noah Calvert, Makalie Lackey, Tanner Livsey, Ryan Langerman, Amy Nguyen, Arnab Mukherjee, Alicia Ito Ford, Matt Vassar
Fibromyalgia trials have largely resolved whether to measure patient-reported outcomes, but instrument selection remains fragmented despite two decades of guidance, limiting comparability across trials. Requiring a consensus-body-endorsed instrument alongside a disease-specific measure would close this gap without sacrificing disease-specific detail.
PURPOSE: Fibromyalgia diagnosis and treatment response depend mostly on patient report, making patient-reported outcomes central to trial evidence. The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials provides recommendations for standardized outcome domains and endorsed patient-reported instruments in chronic pain trials. Whether fibromyalgia trials have converged on a common set of instruments remains unclear. We evaluated instrument standardization and IMMPACT alignment among registered fibromyalgia trials.
METHODS: We conducted a cross-sectional meta-research analysis of 916 interventional fibromyalgia trials registered on ClinicalTrials.gov. Outcomes were classified against an inductively built dictionary of patient-reported outcome instruments, with alignment defined as registration of at least one consensus-body-endorsed instrument. Completeness and alignment were assessed relative to the consensus body's 2005 publication, and cohort assembly and instrument detection were independently verified.
RESULTS: Of 916 eligible trials, 778 (84.9%) named a patient-reported outcome instrument, rising from 47.4% in 2005 to a peak near 98% in 2021. Ninety-five distinct instruments were registered, but only 49.1% of these trials included one the consensus body endorses. The most common measure was the Fibromyalgia Impact Questionnaire, an unendorsed fibromyalgia-specific tool, and the non-endorsed Visual Analog Scale was registered nearly twice as often as the consensus-body-endorsed Numeric Rating Scale (348 vs. 192 trials).
CONCLUSION: Fibromyalgia trials have largely resolved whether to measure patient-reported outcomes, but instrument selection remains fragmented despite two decades of guidance, limiting comparability across trials. Requiring a consensus-body-endorsed instrument alongside a disease-specific measure would close this gap without sacrificing disease-specific detail.