Background/Purpose:

Anti-Nuclear Antibodies (ANA) are found both in patients with (non-)rheumatic diseases and in healthy controls¹. ANA testing is useful in the diagnostic process of Systemic Lupus Erythematodus (SLE), Systemic Sclerosis (SSc), Mixed Connective Tissue Disease (MCTD), Sjögren Syndrome (SS), Polymyositis (PM) and dermatomyositis (DM)^1,2. Laboratory tests in general, are often used inappropriate which leads mainly to overuse of tests.³ This was recently recognized by the American College of Rheumatology and the ANA is now included in the top 5 list of ‘things physicians and patients should question’.⁴ Therefore we aimed to assess the characteristics of ANA testing by rheumatologists in patients visiting the rheumatology outpatient clinic of the Sint Maartenskliniek (SMK) and Maartenskliniek Woerden (MKW), the Netherlands, before and after a targeted educational intervention.   Methods: The characteristics (number, result, final diagnosis) of all ANA tests conducted by rheumatologists between 1-1-2010 and 31-1-2012 (25 months) were compared with the ANA tests done in the four months after the intervention. For fair comparison, the absolute ANA count was corrected for the number of new patients seen at the outpatient clinic in the same period. The intervention consisted of a one-hour, group training in which the individual ordering behavior from the pre-intervention period was given, followed by general background information on ANA test characteristics and the correct use of ANA testing. Directly afterwards all rheumatologists received individual information on their own ANA orders in comparison with their colleagues.  

Results:

All rheumatologists working in both the pre- and post-intervention period at the outpatient clinic participated (n=20). The characteristics of the ANA tests they ordered pre- and post-intervention are summarized in table 1. At both locations a large decrease in the number of ANA tests was seen after the intervention; when corrected for number of new patients seen the decrease was 77% (figure 1).   Conclusion: The finding that our single session intervention resulted in a sizable reduction in number of ANA’s requested, while inter-individual variation and final diagnoses remained unchanged, suggests that excessive usage of ANA tests was reduced without a reduction in appropriate use of the ANA test.

References

¹Solomon DH et al. Arthritis Rheum 2002.²Colglazier CL et al. South Med J 2005. ³van Walraven C et al. JAMA 1998. ⁴Yazdany J. Arthritis Care Res 2013.