Objective
Most published data regarding COVID-19 comes from large cities with high incidence of outbreaks. We sought to evaluate the utility of universal COVID-19 testing in a Midwest region with moderate prevalence of COVID-19.
Study Design
In April, the University of Cincinnati Medical Center began employing universal screening for COVID-19 for all inpatient obstetrical patients. We performed a prospective cohort from April 2020-September 2020, collecting b demographic and medical data, hospital course and pregnancy outcomes. Number needed to test and positive predictive values of various patient symptoms for having COVID-19 were calculated. Asymptomatic patients were defined as not having: subjective fever/chills, cough, headache, shortness of breath, nausea/vomiting, diarrhea, absence of taste/smell. Patients were defined as symptomatic if they had one or more of those symptoms.
Results
811 patients were tested a total of 955 times. In all instances, the test used was a SARS-COV2 PCR from a nasopharyngeal specimen. The COVID-19 test-positive rate was 71/955 (7.4%) and the overall prevalence of COVID-19 in this population was 63/811 (7.8%). Of the COVID-19 positive patients, 36/63 (57.1%) were asymptomatic. The number of asymptomatic patients needed to be tested to detect one COVID-19 patient was 19.3. If a patient was symptomatic on presentation with any of the following: headache, subjective fevers/chills, shortness of breath, nausea/vomiting, diarrhea, loss of taste/smell; the positive predictive value (PPV) was 34.1% vs only 4.6% for asymptomatic patients. If a patient specifically had shortness of breath, the PPV 62.5% and the number of patients needed to test to diagnose one positive was 1.8 patients.
Conclusion
In a medium-sized Midwestern city, the overall COVID-19 prevalence amongst pregnant patients was 7.8% with a positive test rate of 7.4%. In patients without symptoms, the number needed to test to identify one positive patient was 19.3, advocating for universal COVID-19 testing due to high prevalence amongst asymptomatic patients.
