Summary of diagnostic performance in relation to RT-PCR cycle threshold.
There was no clear trend in diagnostic performance in relation to the number of days since first reported symptom among those who commenced participation less than a week after symptom onset, but there was some indication of a decrease in the sensitivity of both index tests among the small number of participants with positive RT-PCR results and a longer symptom duration (Estimated sensitivity (upper two panels) and specificity (lower two panels), with 95% confidence intervals, by number of days since first reported symptom (x-axis), for SD Biosensor (left two panels) and BD Veritor (right two panels). The number of individuals correctly diagnosed by the POCT out of the total are shown towards the bottom of each plot. Participants who did not report specific symptoms and those for whom the timing of symptom onset was unclear are excluded.