Thompson 1982.

Methods	Individual randomization.
Participants	28,000 adults in Eastern Europe: 115 clinics Czechoslovakia, Finland, German Democratic Republic, Hungary, Poland, Romania, Yugoslavia. Mean age 50 (20‐65), attending chest clinic, abnormal chest x‐ray, no previous treatment, no previous positive bacteriology. 1/3 were age 55‐65. PPD>6mm.
Interventions	Isoniazid for 3, 6 or 12 months or placebo.
Outcomes	1. Active tuberculosis 2. Hepatitis
Notes	Only placebo, 6 and 12 month arms included in this analysis (total of 20,828).