# Diagnostic accuracy evaluation of a point-of-care antigen test for SARS-CoV-2 and influenza in UK primary care (RAPTOR-C19)

## TL;DR

This study evaluates a rapid antigen test for detecting SARS-CoV-2 and influenza in UK primary care, finding it highly specific but with moderate sensitivity for SARS-CoV-2 and low sensitivity for influenza.

## Contribution

The study provides new evidence on the diagnostic accuracy of a combined SARS-CoV-2 and influenza antigen test in a primary care setting.

## Key findings

- The test showed high specificity (99.3%) and moderate sensitivity (70.4%) for SARS-CoV-2.
- Sensitivity for Influenza A was 29.1% and for Influenza B was 22.2%, with high specificity for both.
- The test failed to detect the majority of influenza infections despite high specificity.

## Abstract

To evaluate the diagnostic accuracy of the Roche SARS-CoV-2 & Flu A/B Rapid Antigen Test at the point of care.

Prospective diagnostic accuracy study.

17 primary care practices in England.

500 individuals with symptoms consistent with possible SARS-CoV-2 or influenza infection identified upon presentation to primary care or via medical note review.

Sensitivity, specificity and predictive values, compared to a laboratory reference standard of real-time reverse transcription PCR, using samples collected using a combined nasal and oropharyngeal swab.

Of 481 participants with available index and reference test results, 5.6% (27/481) were reference standard-positive for SARS-CoV-2, 11.4% (55/481) for Influenza A and 1.9% (9/481) for Influenza B. The sensitivity of the antigen test to detect SARS-CoV-2 was 70.4% (19/27, 95% CI 49.6–86.2%) and specificity was 99.3% (451/454, 95%CI 98.1–99.9%). For Influenza A, sensitivity was 29.1% (16/55, 95% CI 17.6–42.9%) and specificity 98.6% (420/426, 97.0–99.5%), and for Influenza B, sensitivity was 22.2% (2/9, 2.8–60.0%) and specificity 98.1% (463/472, 96.4–99.1%).

In a primary care population of symptomatic individuals, the assay was highly specific and had moderate sensitivity to detect SARS-CoV-2, but did not detect the majority of influenza infections.

ISRCTN14226970.