Table 1. Summary of assay format characteristics.

Assay Format	HTPA	R&D Assay	EarlyCDT
Antigen batches used	HTPE, R&D or Commercial	R&D or Commercial	R&D or Commercial
Antigen concentration	50 & 100 nM	1.6, 5, 16, 50 & 160 nM	1.6, 5, 16, 50 & 160 nM
Calibration	None	None	Calibrated with specific pleural fluids
Positivity	OD signal > cut-off (50 or 100 nM)	OD signal > cut-off (50 or 160 nM)	RU dose response > antigen cut-off(50 or 160 nM
Cut-off determination	Estimated from mean +2 SD & scatterplots for cohort tested	Estimated from mean +2 SD & scatterplots for cohort tested	Monte Carlo optimized frommulti-centre cohorts