Factors Associated with Fibromyalgia Diagnosis amongst People Meeting Criteria: Results from UK Biobank.

OBJECTIVE: The diagnosis of fibromyalgia (FM) is challenging due to the absence of definitive biomarkers, numerous overlapping comorbidities and its reliance on patient-reported symptoms. Discrepancies between diagnostic criteria and clinical practice imply the possibility of diagnostic biases, complicating timely and accurate identification. This study aimed to identify factors associated with receiving a FM diagnosis, among individuals who met 2016 criteria, and explore potential barriers to diagnosis. METHODS: Using data from UK Biobank, we analysed a total of 27 potential factors across four biopsychosocial domains for differences between individuals who had received a clinician's diagnosis and those who had not. Multivariable log-binomial regression was used within and across domains to evaluate prevalence ratios regarding the independent association of factors with FM diagnosis. RESULTS: Among the 4,197 individuals meeting FM criteria, 72.6% reported not having received a clinician's diagnosis. The identified eight factors significantly associated with not having a diagnosis were: being male, older age, self-reported concomitant diagnosis (presence of neuropathy, absence of chronic fatigue syndrome or complex regional pain syndrome), shorter pain duration, lower polysymptomatic distress scores, and less frequent fatigue. CONCLUSION: In conclusion, the majority of individuals meeting FM criteria did not have a diagnosis. Several factors associated with not receiving clinician's diagnosis are aligned with stereotypical perceptions of FM. These findings highlight areas of future research to facilitate an early diagnosis and improve access to effective treatment for individuals for whom a diagnosis of FM is appropriate.