RESUMO
BackgroundThe novel severe acute respiratory coronavirus 2 (SARS-CoV-2) that causes COVID-19 originated in December 2019 and has now infected over 3 million people in the United States. In Spring of 2020, private laboratories and some hospitals began antibody testing despite lacking evidence-based guidance. ObjectiveTo describe clinician-described indications for SARS-CoV-2 antibody testing, including cost implications, immediately following testing availability. DesignRetrospective chart review of patients who received antibody testing from May 14, 2020 to June 15, 2020. SettingA large academic medical center, one of the first in the US to provide antibody testing capability to individual clinicians. Patients447 consecutive patients who received SARS-CoV-2 antibody testing. MeasurementsClinician-described indications for SARS-CoV-2 antibody testing, cost implications, and comparison with current expert-based guidance from the IDSA and CDC. ResultsOf 444 individual antibody test results meeting inclusion criteria, the two most commonly described indications for ordering the antibody test, apart from public health epidemiology studies (n=223), were for patients with a now resolved COVID-19 compatible illness (n=105) with no previous molecular testing and in asymptomatic patients believed to have had a past exposure or contact with a person with COVID-19 compatible illness (n=60). The rate of positive SARS-CoV-2 antibody testing among those indications consistent with current IDSA and CDC guidance was 17% compared with 5% (p<0.0001) among those indications inconsistent with current IDSA and CDC guidance. Total cost estimates ranged from $57,720 to $97,680, of which 42% was for testing inconsistent with current expert-based guidance. LimitationsThe duration of antibody response following infection is unclear and asymptomatic individuals may not develop a positive antibody response. ConclusionsOur findings demonstrate a dissociation between clinician described indications for testing and expert-based guidance and a significantly different rate of positive testing between these two groups. Clinical curiosity and patient preference appear to have played a significant role in testing decisions and substantially contributed to testing costs.
