The incidence and factors of inappropriate rapid antigen test usage for group A streptococcus.

INTRODUCTION: Although rapid antigen tests (RADTs) for group A streptococcus (GAS) can help diagnose group A streptococcal pharyngitis, little is known about the inappropriate use of these RADTs. METHODS: This retrospective observational study compared the appropriate vs. inappropriate use of RADTs in patients who had a RADT between January 2019 and August 2022. RADTs for patients with a low Centor score of 0-1 point were deemed inappropriate. RESULTS: Of the 1015 patients, 380 (37.4%) had inappropriate RADTs. Patients with asthma were associated with an increased risk of inappropriate testing. In contrast, during the coronavirus 2019 pandemic, outpatients and residents were associated with a reduced risk of inappropriate testing. Consequent to the inappropriate use of RADTs, 162 (16.0%) patients received potentially inappropriate antibiotics. CONCLUSIONS: Our results suggest that diagnostic stewardship for pharyngitis, including education for healthcare workers, is needed to reduce inappropriate test ordering and prevent unnecessary care.