Fibromyalgia in a rheumatology clinic in north‐central Nigeria: An audit of the characteristics of the syndrome and the sensitivities of 4 sets of American College of Rheumatology criteria

Objectives To describe the characteristics of fibromyalgia among Nigerian patients and assess the sensitivities of the American College of Rheumatology (ACR) criteria of 1990, 2010, 2011, and 2016 for making the diagnosis of fibromyalgia. Methods Consecutive patients diagnosed clinically with fibromyalgia by a rheumatologist were assessed. ACR criteria for fibromyalgia of 1990, 2010, 2011, and 2016 were applied to each patient. Polysymptomatic distress scores (PSD) were calculated from the Widespread Pain Index and Symptom Severity Scores. Sleep was assessed using the Pittsburgh Sleep Quality Index; fatigue by the Fatigue Severity Scale and the severity of fibromyalgia was determined using the Revised Fibromyalgia Impact Questionnaire (FIQR). Results A total of 660 new patients were seen out of which a diagnosis of fibromyalgia was made in 114 (17.3%). The mean age of the patients was 44.6 ± 15.6 years and females accounted for 84.2%. Twenty‐one (18.4%) patients had changed or quit their jobs due to fibromyalgia. Problematic fatigue was present in 80 (70.2%), and sleep disturbance was reported in 83 (72.8%) patients. The severity of fibromyalgia, poor sleep, severe or very severe PSD, and male gender were associated with problematic fatigue, but only moderate/severe fibromyalgia independently predicted problematic fatigue (P = .004). The number of tender points (P = .001) and FIQR score (P = .038) were associated with changing or quitting jobs. The sensitivities of the ACR1990, ACR2010, ACR2011 and ACR2016 were 38.5%, 68.2%, 76.7% and 76.7%, respectively. Conclusion The ACR1990 had low sensitivity when used to diagnose fibromyalgia in this population and the ACR2010 encounters problems while applying the somatic symptom list.