Impact of Fibromyalgia on Disease activity in Inflammatory Arthritis: A Cohort Study Conducted at Tertiary Care Hospital of Peshawar, Pakistan

Objective: To determine the frequency of fibromyalgia in patients with inflammatory arthritis and to evaluate the impact of fibromyalgia treatment on disease activity in these patients. Study Design: Prospective cohort study. Place and Duration of Study: Rheumatology Division, Lady Reading Hospital, Peshawar Pakistan, from Apr to Dec 2021. Methodology: A total of 400 patients were enrolled in the study of which 320 were diagnosed with rheumatoid arthritis, 55 with ankylosing spondylitis and 25 with psoriatic arthritis. The diagnosis of fibromyalgia was made with 2016 American College of Radiology Criteria and patients were classified according to the presence or absence of fibromyalgia. Disease Activity Score-28 for Rheumatoid Arthritis with Erythrocyte Sedimentation Rate (DAS28-ESR), Bath Ankylosing Spondylitis Disease Activity Index and Disease Activity in Psoriatic Arthritis Score-28 were recorded for rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis, respectively. Patients of fibromyalgia were treated by either pregabalin or duloxetine with 3-month follow-up. Patients with Widespread Pain Index <7 and Symptoms Severity Scale <5 after treatment for 3 months were labeled as responders. Results: Fibromyalgia was present in 90(28.1%) patients with Rheumatoid Arthritis, 14(25.5%) with ankylosing spondylitis and 8(32%) with Psoriatic arthritis. Fibromyalgia was more common in Rheumatoid Arthritis patients whose disease duration exceeded 5 years (p-value <0.001). Similarly, obesity significantly contributed to Fibromyalgia development in Rheumatoid Arthritis (p-value <0.001) but not in Ankylosing spondylitis and Psoriatic arthritis patients. Disease duration >5 years, obesity, female gender and rising age increased the odds of developing Fibromyalgia in ... Conclusion: Patients with concomitant Fibromyalgia presented higher