Table 3– Cost of diagnosis, per 1,000 cases screened, of different strategies involving pre-screening with an alternative diagnostic test prior to Xpert MTB/RIF assay^#

	Smear microscopy alone	Xpert MTB/RIF alone	Smear microscopy followed by:		CXR followed by:
			Xpert MTB/RIF (if smear negative)	CXR (if smear negative), followed by Xpert MTB/RIF (if CXR suggestive of active TB)	Xpert MTB/RIF (if CXR suggestive of active TB)	Smear microscopy (if CXR suggestive of active TB), followed by Xpert MTB/RIF (if smear negative)
Total test cost $	7420.00	21389.75	24130.74	32471.71	35746.74	36778.00
*Incremental cost versus* smear microscopy alone $**		13969.75	16710.74	25051.71	28326.74	29358.00
Number of correctly diagnosed non-TB cases	683.33	658.33	654.17	648.15	651.23	648.15
Number of correctly diagnosed TB cases	212.50	239.58	254.17	271.60	253.09	271.60
*Additional number of TB cases correctly diagnosed versus* smear microscopy alone**		27.08	41.67	59.10	40.59	59.10
Cost per TB case detected (compared to smear microscopy) $		515.81	401.06	423.85	697.94	496.71

CXR: chest radiograph; TB: tuberculosis. ^#: similar tables stratified by HIV status can be found in the supplementary material (tables S6 and S7).