Work productivity impairment in patients with familial Mediterranean fever and effects of interleukin-1 antagonists

Introduction Familial Mediterranean fever (FMF) is characterized by recurrent attacks of fever, serositis, and arthritis. Some patients suffer from associated inflammatory conditions and damage related to FMF that may potentially impair work productivity which have not been studied to date. Methods Consecutive FMF patients who were attending a tertiary referral center and age-and sex-matched healthy subjects enrolled into the study. Disease activity was assessed with autoinflammatory disease activity index (AIDAI) and patient global assessment. Damage was evaluated using Autoinflammatory Disease Damage Index (ADDI). Quality of life (QoL) and work productivity were determined with 36-Item Short Form Health Survey (SF-36) and Work Productivity and Activity Impairment Specific Health Problem v2.0 (WPAI:SHP), respectively. Results There were 111 FMF patients, 60 female (54%), mean age 32.7 +/- 8.7 years. There were significant impairments in all domains of the SF-36 QoL in FMF patients. Of the 111 patients enrolled, 65 (58.6%) were employed in a paid work. Mean% +/- SD impairment in work productivity both assessed as absenteeism (9.3 +/- 23.2% vs. 0.7 +/- 2.6, p=0.013) and presenteeism (35.2 +/- 32.6% vs. 9.6 +/- 14.7, p<0.001) were significantly higher in FMF patients compared to healthy subjects. Impairment in work productivity was correlated with the number of attacks, disease activity, colchicine resistance, and disease-associated damage. Impairment was most significant in colchicine-resistant FMF patients but lower in those on interleukin (IL)-1 antagonist treatments. Conclusions FMF causes significant work impairment and reduced QoL which is associated with disease activity and damage. The use of IL-1 antagonists may help to improve work productivity and QoL in FMF patients with frequent attacks. Key points Work productivity is impaired in patients with FMF. Disease activity was an independent predictor for impaired work productivity. IL-1 antagonists may improve work productivity and quality of life in FMF patients with frequent attacks.