Prevalence of fibromyalgia in fourteen Korean tertiary care university hospital pain clinics.

Purpose: We aimed to investigate the prevalence of fibromyalgia (FM) in patients who visited outpatient pain clinics in Korea, using the modified 2010 American College of Rheumatology (ACR) criteria and to evaluate comorbid conditions that may be associated with FM.

Patients and methods: Outpatients, aged ≥18 years, who first visited pain clinics at any of the 14 tertiary care university hospitals, were recruited for this study. Modified 2010 ACR criteria were used to diagnose FM. Participants' demographic information and eleven comorbid measures (sleep disturbance, fatigue, irritable bowel syndrome, amnesia, hypothyroidism, headache, anxiety, depression, rheumatism, low back pain, and history of traffic accident) were also investigated via additional questionnaires.

Results: We recruited 1,233 outpatients (754 men and 479 women). Based on the modified 2010 ACR criteria, 13.38% (165/1,233 patients, 95% CI: 11.48-15.28) of patients had FM. As participants with a history of FM were excluded, the prevalence of FM was 11.0% (123/1,118 patients). Patients with FM were more likely to have one or more of the eleven predetermined comorbid conditions. Patients who were female and who had a previous history of FM, sleep disturbance, headache, or a history of traffic accident were more likely to have FM.

Conclusion: FM, according to the modified 2010 ACR criteria, appears to be a common disorder among chronic pain patients referred to tertiary care university hospital pain clinics. Therefore, physicians treating pain should consider this prevalence of FM among pain clinic patients.