Identification of undiagnosed inflammatory arthritis in a community health fair screen.

Objective: To identify individuals with undiagnosed inflammatory arthritis (IA) and rheumatoid arthritis (RA) in a community health fair screen, and to establish in a health fair setting the diagnostic accuracy of combinations of the Connective Tissue Disease Screening Questionnaire (CSQ) and autoantibody testing for IA.

Methods: Screening for IA/RA was performed at health fair sites using a combination of the CSQ, joint examination, rheumatoid factor, and anti-cyclic citrullinated peptide (anti-CCP) antibody testing. IA was defined as > or =1 swollen joint suggestive of synovitis on joint examination by a trained clinician.

Results: Six hundred one subjects were screened; 51.0% participated because of joint symptoms (pain, stiffness, or swelling). Eighty-four subjects (14.0%) had > or =1 swollen joint, designated as IA on joint examination. Of the 601 subjects screened, 9 (1.5%) had IA and met > or =4 of 7 American College of Rheumatology criteria for RA but had no prior diagnosis of RA, and 15 (2.5%) had IA and RF and/or anti-CCP positivity, suggesting early RA. The diagnostic accuracy of combinations of the CSQ and autoantibody testing for the identification of IA yielded maximal sensitivity, specificity, and positive and negative predictive values of 95.3%, 99.2%, 71.4%, and 97.7%, respectively.

Conclusion: Health fair screening may be an effective approach for the identification of individuals with undiagnosed IA/RA. A combination of the CSQ and autoantibody testing alone has clinically useful diagnostic accuracy for the detection of IA. Decisions regarding which methodology to use for future health fair IA/RA screening will depend on goals of screening and funding.