Quality assessment of the studies (1 = yes; 0 = no).

Notes: We treat each category as binary and assign values “0” or “1”. 1) “data collection year”: whether or not the data collection year was provided in the study. If yes, “data collection year” = 1, 0 otherwise; 2) “national estimate”: whether or not the cost was estimated at national level. If yes, “national estimate” = 1, 0 otherwise; 3) “specification of test type”: whether or not the test type was provided in the study, e.g. ZN/FM, MGIT/LJ. If yes, “specification of test type” = 1, 0 otherwise; 4) “direct data source”: whether or not the cost was directly collected from health facilities (e.g. hospital, clinic, laboratory etc.). If yes, “direct data” = 1, 0 otherwise; 5) “specification of cost items”: whether or not the study described the components included in cost estimation. If yes, “specification of cost items” = 1, 0 otherwise. All the studies are ranked by the summation of five scores from highest to lowest.