Association Between Isolated Regional Pain and Subsequent Fibromyalgia Documentation: A Retrospective Text-Mined
Shachar Zion Shemesh1,2, Yotam Hadari2, Lior Ungar1,3,4
1Department of Neurosurgery, Sheba Medical Center, Ramat Gan, Israel.
Background:
Fibromyalgia may be documented after years of regional pain, but the localized presentations associated with subsequent fibromyalgia documentation in pain-clinic practice remain poorly defined. Documentation in health records may reflect delayed recognition rather than biological disease onset.
Objective:
To quantify subsequent fibromyalgia documentation after isolated, localized non-fibromyalgia pain presentations and to describe associated demographic and diagnostic patterns without inferring causality or biological progression.
Methods:
We conducted a retrospective longitudinal cohort study of 58,650 patients seen from June 2009 to June 2021, with follow-up through June 2026. Inclusion required exactly one localized non-fibromyalgia pain category on the first observed pain-clinic day, no non-negated fibromyalgia signal on that day, and at least five years of observed follow-up. A fibromyalgia signal was defined as at least one prespecified, non-negated fibromyalgia expression on a patient-day. Bilingual rule-based dictionaries identified pain categories and fibromyalgia. Proportions used patient-level denominators and Wilson confidence intervals.
Results:
Among 23,103 isolated-index patients, 13,391 had a five-year potential observation window and 2,783 had observed five-year follow-up. Later fibromyalgia was documented in 299 patients (10.74%, 95% CI 9.65-11.95) after a median 4.49 years. Patients with later documentation were younger than those without it. Sex-stratified proportions were 10.91% in women and 8.30% in men; these descriptive estimates do not establish an independent sex effect. High point estimates in small subgroups were imprecise.
Conclusion:
Selected localized pain documentation phenotypes were associated with subsequent fibromyalgia documentation. These patterns may support earlier clinical assessment but do not establish biological progression or causality.
