Of the @ patients who underwent randomization , in the per-protocol analysis , a favorable outcome was reported in fewer patients in the isoniazid group ( @ % ) and the ethambutol group ( @ % ) than in the control group ( @ % ) , for a difference favoring the control group of @ percentage points ( @ % confidence interval -LSB- CI -RSB- , @ to @ ) versus the isoniazid group and @ percentage points ( @ % CI , @ to @ ) versus the ethambutol group .