COVID-19 Preprocedural Testing: What About the False Positives?

In the COVID-19 era, preprocedural patients are almost uniformly screened for symptoms, asked to quarantine preoperatively, and then undergo a test of uncertain validity with very low pretest probability. A small percentage of these tests return positive. As a result, surgical procedures are delayed and patients are required to quarantine. Are these asymptomatic patients truly positive for COVID-19? What are the impacts of these test results on the patient and the health care system? In the following commentary, we review how the uncertain validity of reverse transcription polymerase chain reaction testing combined with a low-prevalence population predisposes for false-positive results. As a mitigation strategy, we ask that readers refocus on the fundamental principal of diagnostic testing: pretest probability.