Utility of point-of-care COVID-19 testing in an outpatient otolaryngology clinic

Introduction: We aimed to evaluate the utility of point-ofcare COVID-19 testing for identifying infected patients in an otolaryngology practice, given the potential for overlap in presenting symptoms. Method: Retrospective review of 947 patients who tested using the Abbott ID Now point-of-care SARS-CoV-2 nucleic acid test (NAT) in an otolaryngology clinic from July to November 2020 was performed. Tests were characterized by provider-specified indication (symptomatic, preprocedural, and universal), subspecialty, provider type, and contemporaneous regional COVID positivity rates. Positive tests were further classified as true positives (TP) and false positives (FP) based on repeat polymerase chain reaction testing when available, and intergroup positivity rates were compared using the Fisher exact test. The likelihood of a FP result within 48 hours of a TP result was also evaluated to assess for batch contamination. Results: We performed 947 SARS-CoV-2 NATs, yielding 9 TPs (0.95%) and 5 FPs (0.53%) results. Of these, 158 (5 TP, 2 FP) were for symptomatic patients, 303 (2 TP, 1 FP) were for preprocedural, and 486 (2 TP, 2 FP) for universal testing indications. The TP rates were significantly different by testing indication, with higher rates among symptomatic patients (P = .012;symptomatic vs universal odds ratio [OR] = 7.877;95% CI, 1.274-83.694;symptomatic vs preprocedural OR = 4.900;95% CI, 0.791-52.001). TP rates were also significantly different by subspecialty (P = .011), with significant intersubspecialty differences driven by higher rates in laryngology. TP rates were significantly higher among PA encounters than those with physicians (P = .0005;OR = 13.1442;95% CI, 2.7697-67.7222). TP rates were not significantly different during periods of local outbreak, defined using an Illinois Department of Public Health threshold of 12% test positivity rate (P = .660). FP rates were not significantly higher if performed within a 48-hour window of a TP test (P = .192). Conclusion: Point-of-care COVID-19 NAT in an outpatient otolaryngology clinic identified a low (<1%) rate of TP with most cases being clinically suspected. Laryngology patients and patients acutely seeing a PA may have higher positivity rates.