Hong Kong 1979a.

Methods	Randomized trial of 2‐, 3‐, and 12‐month regimens, with shorter regimens containing 4 drugs.
Participants	1212 adults with sputum smear negative, radiographically active TB. 691 culture negative, 381 culture positive, analyzed separately. Excluded from relapse analysis: Pretreatment ineligiblity: 9/1212 (1%) Side effects: 32/691 (5%) (culture negative patients only) Other reasons: 91/691 (13%) (culture negative patients only)
Interventions	2SHRZ 3SHRZ 3SPH/9SHI Daily dosages: S: 0.75 g H: 300 mg R: 450 mg Z: 1.5 g (<50 kg), 2.0 (>50 kg) PAS: 10 g Intermittent (2X/week): S: 1.0 g H: 15 mg/kg
Outcomes	Bacteriologic relapse 12 months after starting treatment.
Notes	Follow‐up period is shorter than other studies.