| XDR alone | XDR+2sli | XDR+sliG4 | XDR+sliG4EZ | |
| Subjects | 301 | 68 | 48 | 42 |
| Group 1 | ||||
| Ethambutol | 222/280 (79) | 55/68 (81) | 30/30 (100) | 30/30 (100) |
| Pyrazinamide | 138/230 (60) | 47/51 (92) | 32/32 (100) | 32/32 (100) |
| Group 2 | ||||
| Fluoroquinolones# | 301/301 (100) | 68/68 (100) | 48/48 (100) | 42/42 (100) |
| Group 3 | ||||
| Streptomycin | 208/292 (71) | 68/68 (100) | 27/27ƒ (100) | 26/26ƒ (100) |
| Kanamycin/amikacin¶ | 279/301 (93) | 68/68 (100) | 48/48 (100) | 42/42 (100) |
| Capreomycin | 26/207 (13) | 68/68 (100) | 48/48ƒ (100) | 12/12ƒ (100) |
| Resistant to kanamycin/amikacin and capreomycin | 14/301 (5) | 68/68 (100) | 12/12ƒ (100) | 12/12ƒ (100) |
| Resistant to all injectables+ | 0/301 (0) | 68/68 (100) | 12/12ƒ (100) | 12/12ƒ (100) |
| Group 4§ | ||||
| Ethionamide or prothionamide | 138/257 (54) | 38/64 (59) | 47/47 (100) | 41/41 (100) |
| Cycloserine or terizidone | 59/235 (25) | 12/59 (20) | 26/26 (100) | 26/26 (100) |
| Para-aminosalycilic acid | 87/228 (38) | 26/56 (46) | 21/21 (100) | 21/21 (100) |
| Resistant to less than half of group 4 drugs tested | 164 (63) | 40 (61) | 0 | 0 |
| Resistant to half or two-thirds of group 4 drugs tested | 60 (23) | 11 (17) | 0 | 0 |
| Resistant to all group 4 drugs tested | 38 (15) | 15 (23) | 48 (100) | 42 (100) |
Data are presented as n, n/N (%) or n (%). No information was collected regarding group 5 drug susceptibility test results. XDR alone: resistance to isoniazid and rifampicin, plus any fluoroquinolone and any second-line injectable drug (sli); XDR+2sli: XDR-TB, plus resistance to both an aminoglycoside injectable (kanamycin/amikacin) and to capreomycin; XDR+sliG4: XDR-TB, plus resistance to all second-line TB drugs tested, with, as a minimum, resistance to kanamycin and to at least one group 4 drug (G4); XDR+sliG4EZ: XDR-TB, plus resistance to all first- and second-line TB drugs tested, with, as a minimum, resistance to kanamycin, one group 4 drug and either pyrazinamide (Z) and/or ethambutol (E). #: all patients were, by definition, resistant to fluoroquinolones as they all met the definition of extensive drug resistance. Nearly all laboratories reported a single result for fluoroquinolones susceptibility testing; generally for ofloxacin susceptibility. ¶: kanamycin and amikacin susceptibility results are shown together because participating laboratories tested for one drug or the other but very few tested for both. Hence these results were considered equivalent. +: resistant to streptomycin, kanamycin, amikacin and capreomycin. §: group 4 drug resistance was categorised as: resistant to less than half of those tested; resistant to half or two-thirds of those tested; and resistant to all group 4 drugs tested. ƒ: in these groups, patients were resistant to all injectables tested, but the minimum requirement was that they were tested for susceptibility to kanamycin/amikacin. Hence many were not tested for susceptibility to capreomycin and/or streptomycin.