a. These recommendations apply to the use of LPAs for testing sputum smear-positive specimens (direct testing) and cultured isolates of MTBC (indirect testing) from both pulmonary and extrapulmonary sites. b. LPAs are not recommended for the direct testing of sputum smear-negative specimens. c. These recommendations apply to the detection of MTBC and the diagnosis of MDR-TB but acknowledge that the accuracy of detecting resistance to rifampicin and isoniazid differs and, hence, the accuracy of a diagnosis of MDR-TB is reduced overall. d. These recommendations do not eliminate the need for conventional culture-based DST, which will be necessary to determine resistance to other anti-TB agents and to monitor the emergence of additional drug resistance. e. Conventional culture-based DST for isoniazid may still be used to evaluate patients when the LPA result does not detect isoniazid resistance. This is particularly important for populations with a high pre-test probability of resistance to isoniazid. f. These recommendations apply to the use of LPA in children based on the generalization of data from adults.