Background/Purpose:

Early identification and treatment of inflammatory arthritis (IA) and in particular rheumatoid arthritis (RA) can lead to improved outcomes. However, there are often delays in diagnosis. We hypothesized that evaluation of individuals in a health-fair setting could identify those with previously undiagnosed IA/RA. In addition, because performing physical examinations is difficult to perform on a large scale, we sought to evaluate the diagnostic characteristics of self-reported symptoms and antibody testing to identify IA.

Methods:

Subjects who self-reported no prior diagnosis of RA were evaluated from 2012 to 2015 at a Colorado based health-fair. Each subject reported presence/absence and location of joint symptoms in the wrists and hands on a cartoon picture of these joints. All subjects additionally underwent ACPA testing (CCP3, Inova) and a joint examination of the wrists and hands (excluding DIPs) by a rheumatologist who recorded presence/absence of IA. The diagnostic accuracy of symptoms and ACPA as single variables or an overall score were evaluated using regression techniques.

Results:

1703 subjects were evaluated, and 98 (5.8%) were found to have IA (Table 1). Of single joint areas, self-reported symptoms of joint pain, stiffness or swelling in the MCPs had the strongest association with the presence of IA on examination (OR 4.8). CCP3(+) was also significantly associated with IA (OR 3.1) but was present in only 8% of all subjects with IA, and 45 subjects were CCP3(+) without hand/wrist IA. In multivariate analyses, four variables including symptoms in wrists, MCPs, PIPs, and CCP3(+) were significantly associated with IA. When these 4 variables were evaluated as counts, the highest positive predictive value (PPV) for IA was 22% (³3 items present), and the highest negative PV was ~98% (0 items present) (Table 2).

Conclusion:

Health-fair evaluations can be used to identify individuals with IA, some of whom likely have RA due to CCP3(+), and others with potentially other forms of IA. A scoring system using a combination of self-reported joint symptoms and CCP3 testing can be used to identify those with IA in the hands, with varying predictive values depending on the score used. Further evaluations including determining what specific forms of arthritis are identified and cost-effectiveness need to be performed, but overall these findings support a health-fair based approach using questionnaires and ACPA testing as a way to improve identification of IA. Additionally, N=46 CCP3(+) subjects did not have IA, indicating this method could be used to identify individuals at future risk for RA.