Singapore 1979a.

Methods	Randomized trial of 2 4‐month and 2 6‐month regimens, each with 4 drugs in initial 2‐month phase.
Participants	400 sputum‐positive pulmonary TB patients, age 15 or more, with no previous anti‐TB treatment entered. Excluded from relapse analysis: Pretreatment ineligibility: 12/400 (3%) Adverse reactions: 19/400 (5%) Given wrong drugs: 2/400 (1%) Died: 1/400 (0%) Defaulted: 3/400 (1%) 37 excluded for pre‐treatment ineligiblity. 345 assessed at 30 months (314 with initially drug‐susceptible strains and 31 resistant to at least one drug initially)
Interventions	Daily treatment (70% of participants were outpatients), under direct observation, with the following 4 regimens: 2SHRZ/4HRZ 2SHRZ/4HR 2SHRZ/2HRZ 2SHRZ/2HR Daily dosage: S: 0.75g H: 300 mg R: 450 mg (<50 kg), 600 mg (>50 kg) Z: 1.5 g (<50 kg), 2.0 g (>50 kg)
Outcomes	Sputum conversion during and immediately after treatment Bacteriologic relapse (culture positive) at 6 and 30 months and 5‐8 years after start of treatment Adverse reactions
Notes	Includes a small number of patients in each group with bacilli resistant to H, R, or both. All patients with sensitive bacilli were culture‐negative by the end of month 3 of treatment.