The combination of the connective tissue diseases questionnaire plus rheumatoid factor and anti-cyclic citrullinated peptide antibody positivity had a 95% sensitivity and 32% specificity for identifying people with at least one swollen joint at free community health fairs.
The study, presented at the Western regional meeting of the American Federation for Medical Research, is one of few to examine rheumatoid arthritis screening techniques in the community health fair setting, where more prevalent conditions, such as diabetes and hypertension, receive more attention. The nonprofit 9Health administers volunteer-driven health fairs in Colorado that offer a variety of free or low-cost screenings to more than 90,000 people per year.
In all, 601 participants (16% of total attendees) were screened at five sites in the Denver area. The researchers administered the 30-item questionnaire (Ann. Epidemiol. 1995;5:297-302) as well as blood tests for rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP). The patients' joints were examined by a rheumatologist who was unaware of the assay and questionnaire results.
Of those screened, 84 people (14%) had one or more swollen joints that would be consistent with possible inflammatory arthritis, said Dr. Kevin Deane of the division of rheumatology of the University of Colorado, Denver. “Nine met at least four ACR criteria for RA but never had a prior diagnosis,” he said in an interview.
“An additional 15 people had a swollen joint and RF or CCP positivity, but met fewer than four ACR RA criteria. They may have early RA,” he added. And another 41 people had either RF or anti-CCP positivity but didn't have any arthritis. “So something is going on immunologically, but no arthritis yet,” he said.
“The importance of identifying RA early is growing,” Dr. Deane said, but finding people with early disease remains difficult. “We thought we would try to utilize the health fair to screen a pretty large population.”
The cost of the screening effort is $42 per person screened, which does not include salaries because the study relied on volunteers. “If you count person-hours into this, this health fair screen cost about $2,000 to identify each person with RA or inflammatory arthritis,” said Dr. Deane.
“What we don't know is, is that worth it? We think so; if you identify and treat RA early, you should reduce disability and lost work time. More study is needed to find out the true cost/benefit of this approach,” he said.
A follow-up study aiming to screen 5,000 health fair attendees is planned for later this year. Abbott Laboratories supported the cost of screening and assays, and was a cosponsor of the 9Health Fair, along with Quest Diagnostics Inc. and GE Healthcare. The authors disclosed no relevant conflicts of interest.