Table 2. Clinical characteristics of patients with late recurrent TB*, California 1993–2007.
| Characteristic | Recurrent TB*n (%) | Single episode TBn (%) | Unadjusted hazard ratio (95% CI) | p-value | |
| No. | 148 | 23,369 | |||
| Sputum AFB smear positive | Yes | 103 (70) | 12,541 (54) | 1.97 (1.37–2.83) | 0.0002 |
| No | 41 (28) | 9,533 (41) | Ref | ||
| Unk | 4 (3) | 1,295 (6) | |||
| Cavitary chest radiograph | Yes | 51 (34) | 5,739 (25) | 1.63 (1.16–2.29) | 0.0051 |
| No | 94 (64) | 16,983 (73) | Ref | ||
| Unk | 3 (2) | 647 (3) | |||
| HIV positive | Yes | 21 (14) | 1,390 (6) | 2.46 (1.55–3.90) | 0.0001 |
| No | 127 (86) | 21,979 (94) | Ref | ||
| INH mono-resistance | Yes | 3 (2) | 2,040 (9) | 0.22 (0.07–0.67) | 0.008 |
| No | 145 (98) | 21,329 (91) | Ref | ||
| PZA mono-resistance | Yes | 5 (3) | 354 (2) | 2.76 (1.13–6.74) | 0.0255 |
| No | 143 (97) | 23,015 (98) | Ref | ||
| MDR | Yes | 4 (3) | 285 (1) | 2.56 (0.95–6.92) | 0.064 |
| No | 144 (97) | 23,084 (99) | Ref |
Definition of abbreviations: Ref = reference group; Unk = unknown or missing; HIV = Human immunodeficiency virus; INH = isoniazid; PZA = pyrazinamide; AFB = acid fast bacilli; MDR = multidrug-resistant.
*Characteristic present in the first episode of patients with late recurrent TB (see text for details).