INTRODUCTION The use of various diagnostic techniques is increasingly common in pandemic scenarios. It is important to update evaluations of their metric properties in different times and settings.

OBJECTIVE Evaluate metric properties of a SARS-CoV-2 rapid antigen test relative to a reference standard.

METHODS We carried out a prospective evaluation study of the SARS-CoV-2 rapid antigen test as compared to the RT-PCR test, which is considered the reference standard. Our sample was comprised of 778 individuals, and we calculated sensitivity, specificity, predictive values, prevalence and validity indices.

RESULTS Of the total 778 samples, 70 were true positives, 658 were true negatives, and 27 were false negatives when compared to RT-PCR test results. We obtained a sensitivity of 75.3% (95% CI = 65.96–84.50); a specificity of 96.1% (95% CI = 94.53–97.59); 72.2% for positive predictive value, and 96.6% for negative predictive value. The estimated prevalence was 11.9% and the validity index was 93.6%.

CONCLUSIONS The index values validate use of the SARS- CoV-2 rapid antigen test until prevalence falls below 2.5%, since as SARS-CoV-2 infection prevalence decreases, so does the predictive value of the PCR result.

The use of the SARS-CoV-2 rapid antigen test on the Isle of Youth, Cuba, was decisive in the pandemic’s clinical– epidemiological management.

KEYWORDS SARS-CoV-2, COVID-19, antigens, validation study, sensitivity and specificity, Cuba