OP0302 An evaluation of utilisation patterns and appropriateness of laboratory tests among new referrals to rheumatologists: choosing unwisely!
Authors: A. Ahrari, S.S. Barrett, S. Rohekar, P. Basharat, G. Rohekar, S. Haig, J. Pope
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Laboratory testing including autoantibodies are common investigations ordered by physicians in diagnosing rheumatic diseases. Tests such as rheumatoid factor (RF) and antinuclear antibody (ANA) have been shown to have low positive predictive value and questionable clinical utility in general practice.<sup>1–3</sup>Optimizing value in medical care is a worldwide concern. In addition, overuse of diagnostic tests can increase health resource use, lead to unnecessary referrals, and cause anxiety associated with positive results. To that end, the Canadian Rheumatology Association (CRA) joined the national Choosing Wisely Canada Campaign and developed a list of 5 tests with evidence indicating they may not be adding value and in fact be harmful. Among these, ANA testing was identified as one of the tests often inappropriately ordered.<sup>3</sup> When combined with extractable nuclear antibodies (ENA) and anti-dsDNA, these tests impose a significant cost. <h3>Objectives</h3> To evaluate the utilisation patterns, appropriateness, and associated cost of tests (ANA, ENA, anti-dsDNA, RF, and complement levels) in patients referred to rheumatologists 2 years after release of CRA choosing wisely guidelines. <h3>Methods</h3> A chart audit reviewing the records of all referred patients to five rheumatologists at an academic university out-patient rheumatology clinic over one year (including referrals that were rejected) was conducted. Specific tests requested prior to referral and their indication based on clinical presentation were extracted. Other data included reason for referral and the final diagnosis. The number of unnecessary laboratory tests and associated costs were calculated. <h3>Results</h3> Over 500 patients were reviewed. Most common referrals were for possible diagnosis of rheumatoid arthritis, lupus, and seronegative spondyloarthropathies. Prior to referral: 77% had undergone ANA testing at least once, in one-third of cases, ANA was repeated; 25% had ENA testing and 30% had anti-dsDNA. Among all ANA tests, 25% were requested when there was no clinical suspicion for connective tissues diseases based on American College of Rheumatology criteria. Half of ENA and anti-dsDNA testing was requested in the context of negative ANA. RF was requested in 65% of the referrals and in one third, there was no clinical suspicion of inflammatory arthritis. <h3>Conclusions</h3> RF, ANA, ENA, and anti-dsDNA are among commonly ordered investigations prior to referral to rheumatology. Despite the recommendations by choosing wisely campaigns, up to 50% of investigations are inappropriately ordered. Based on our cost estimation, more selective ordering of the above tests, and minimising inappropriate investigations would lead to 45% cost reduction. <h3>References</h3> [1] Abeles AM, Abeles M. The clinical utility of a positive antinuclear antibody test result. <i>AJM</i>2013;126(4):342–348. doi:10.1016/j.amjmed.2012.09.014 [2] Miller A, Mahtani KR, Waterfield MA, Timms A, Misbah SA, Luqmani RA. Is rheumatoid factor useful in primary care? A retrospective cross-sectional study. Clin Rheumatol2013;32(7):1089–1093. doi:10.1007/s10067-013-2236-0 [3] Fritzler MJ. Choosing wisely: Review and commentary on anti-nuclear antibody (ANA) testing. Autoimmunity Reviews. 2016;15(3):272–280. doi:10.1016/j.autrev.2015.12.002 <h3>Disclosure of Interest</h3> None declared