Eff ect of improved tuberculosis screening and isoniazid preventive therapy on incidence of tuberculosis and death in patients with HIV in clinics in Rio de Janeiro , Brazil : a stepped wedge , cluster-randomised trial
Methods We did a stepped wedge, cluster-randomised trial with patients actively enrolled in 29 HIV clinics in Rio de Janeiro. Clinic staff were trained in tuberculosis screening, use of tuberculin skin tests, and use of isoniazid preventive therapy. Clinics were randomly allocated a date to begin the intervention period, with two clinics beginning the intervention every 2 months starting from Sept 1, 2005. The primary outcome was tuberculosis incidence alone or combined with death in the control versus intervention periods until Aug 31, 2009. This trial is registered at ClinicalTrials.gov, number NCT00107887.