TABLE 2.

Proportional hazards models for association of hair drug concentrations and time to failure

Predictor	Patients n	Events n	HR (95% CI)	p-value
Drug concentrations
Mean Z-score#	47	11	0.60 (0.27–1.34)	0.21
Isoniazid	22	3	1.40 (0.39–5.0)	0.61
Pyrazinamide	44	11	0.58 (0.31–1.09)	0.091
Ethambutol	34	6	0.79 (0.34–1.8)	0.58
Levofloxacin	28	5	1.21 (0.52–2.8)	0.66
Moxifloxacin	19	6	0.95 (0.42–2.2)	0.91
Bedaquiline	25	4	0.42 (0.10–1.7)	0.23
Clofazimine	31	8	0.54 (0.27–1.08)	0.081
Linezolid	22	3	0.55 (0.10–3.1)	0.50
Clinical and demographic risk factors
Age	47	11	0.61 (0.28–1.31)	0.20
HIV-positive	47	11	3.1 (0.67–14.4)	0.15

Mean anti-tuberculosis drug Z-score was calculated for each participant by averaging Z-scores (difference from the mean, divided by the standard deviation) for all hair drug concentrations for a given participant; this constituted the primary predictor. ^#: this was the primary predictor.