Background   Fibromyalgia (FM) is one of the most common causes of chronic widespread pain. FM is characterized by a complex polysymptomatology that also comprises fatigue, sleep disturbances and functional symptoms. The knowledge of FM in the doctors is still insufficient in China.

  Objective   To investigate the misdiagnosis of FM, and explore the factors leading to the misdiagnosis.

  Methods   The patients diagnosed as FM in the department of rheumatology of the First Medical Center of Chinese PLA General Hospital from June 2016 to December 2017, who also had a visiting history to other hospitals, were included. Clinical features and previous diagnosis were collected. The differences of clinical features between the patients correctly diagnosed and those misdiagnosed were compared.

  Results   The study included 70 FM patients who had 110 clinic visits in other tertiary and secondary hospitals. The mean age of the patients was 38 years, and 88.6% of the patients were female. Only 9 visits (8.2%) were correctly diagnosed as FM. The most common misdiagnosis was spondyloarthritis (27 visits, 24.5%), followed by rheumatoid arthritis (6 visits, 5.5%), Bi syndrome (11 visits, 10.0%), anxiety and/or depression (7 visits, 6.4%), other diseases (24 visits, 21.8%) and no definite diagnosis (26 visits, 23.6%). The rate of correct diagnosis was 9.3%(9/97) in Grade A tertiary hospitals, and 0(0) in Grade B tertiary hospitals and secondary hospitals. Among the 51 clinic visits for 44 patients in the department of rheumatology in a tertiary A hospitals, only 6 visits (11.8%) were correctly diagnosed as FM. The patients who were misdiagnosed had less tenderness points (8.0 vs 14.5, P=0.039) than the correctly diagnosed patients, and no significant difference was found in age, sex, ESR, HLA-B27, widespread pain index, and symptom severity scale, et al. between the two groups (all P＞0.05).

  Conclusion   FM is underdiagnosed in the secondary and tertiary hospitals in China, and the knowledge of FM in the doctors including rheumatologists is still severely insufficient. The doctors tend to diagnose FM heavily depending on the number of tenderness points, while ignore the value of other signs and symptoms, which is the major reason for misdiagnosis of FM.