Overutilization and underutilization of autoantibody tests in patients with suspected autoimmune disorders

Diagnostic Management Teams (DMTs) are one strategy for reducing diagnostic errors. This study examined errors in serology test selection after a positive antinuclear antibody (ANA) test in patients with suspected systemic autoimmune rheumatic disorder (SARD).

This retrospective study included 246 patient cases reviewed by our ANA DMT from March to August 2019. The DMT evaluated the appropriateness of tests beyond ANA screening tests (overutilization, underutilization, or both) based on American College of Rheumatology recommendations and classified cases into diagnostic error or no error groups. Errors were quantified, and patient and provider characteristics associated with diagnostic errors were assessed.

Among 246 cases, 60.6% had at least one diagnostic error in test selection. The number of sub-serology tests ordered was 2.4 times higher in the diagnostic error group than in the no error group. The likelihood of at least one diagnostic error was higher in males and African American/Black patients, although the differences were not statistically significant. Providers from general internal medicine, primary care, and non-rheumatology specialties were approximately two times more likely to make diagnostic errors than rheumatology specialists.

Diagnostic errors in test selection after a positive ANA for patients with suspected SARD were common, although there were fewer errors when ordered by rheumatology specialists. These findings support the need to develop strategies to reduce diagnostic errors in test selection for autoimmunity evaluation and suggest that implementation of a DMT can be useful for providing guidance to clinicians to reduce overutilization and underutilization of laboratory tests.