Background/Purpose:

The ACR Choosing Wisely Campaign top 5 lists highlight the appropriate use of autoantibody testing, thereby reducing unnecessary spending. Positive antinuclear antibodies (ANA) are one of the most common reasons for referral to pediatric rheumatology clinics. The prevalence of positive ANAs in the pediatric population ranges from 3 – 36%. ANAs are useful when used for confirmation of a suspected diagnosis and for risk stratification of a known diagnosis, but ANAs are often inappropriately used to screen for autoimmunity resulting in positive tests with unclear clinical significance. We hypothesize that a large amount of health care dollars are spent on laboratory and radiographic tests related to a positive ANA and that general pediatricians are more likely to order an ANA than pediatric rheumatologists when confronted with the same clinical scenario.

Methods:

We conducted a retrospective chart review of new patients referred for a positive ANA to the pediatric rheumatology clinic at our institution from July 1, 2010 through June 30, 2011. We recorded findings from the history and physical examination, any studies ordered prior to and at the time of the rheumatology visit, and the final diagnosis. The history, physical examination, and baseline laboratories were reviewed by 2 pediatric rheumatologists, 3 pediatric hospitalists, and 2 ambulatory pediatricians blinded to the final diagnosis, ANA titer, and other studies. The reviewers indicated whether they would have ordered an ANA. A list of gross charges for the studies was obtained from the laboratory and department of radiology at our institution.

Results:

Seventy-five patients were identified. The total charges equaled $195,402 with a mean of $2,605 per patient. Only 5 patients had a primary rheumatologic disease. Two patients had lupus, 2 had JIA, and 1 had UCTD. Hypermobility was the most common diagnosis, and 24% of patients had a negative ANA on repeat testing. There was a significant difference in the total charges per patient based on the final diagnosis (primary rheumatologic disease vs. other diagnosis, p = 0.0499). The interrater reliability between all 7 reviewers was fair with an intraclass correlation coefficient of 0.303; it was moderate between rheumatologists with a kappa statistic of 0.478. There was not a significant difference between the number of ANAs ordered by the 3 groups. The responses for the patients with a rheumatologic disease were analyzed. The rheumatologists agreed on ordering an ANA for all these patients, but there was disagreement among the general pediatricians.

Conclusion:

ANAs are useful when used appropriately, but they generate large amounts of unnecessary spending if used inappropriately. Most patients with a positive ANA did not have an autoimmune disease bringing into question the necessity of the initial ANA test. When comparing the utilization of ANAs between pediatric rheumatologists and general pediatricians, there was not a significant difference in the number of tests ordered; however, the rheumatologists more accurately identified patients with a rheumatologic disease.

---

« Back to 2014 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-price-of-a-positive-test-is-it-worth-the-cost/