The safety, effectiveness and cost-effectiveness of cytisine in achieving six-month continuous smoking abstinence in tuberculosis patientsprotocol for a double-blind, placebo-controlled randomized trial

Background and aims Tuberculosis (TB) patients who quit smoking have much better disease outcomes than those who continue to smoke. In general populations, behavioural support combined with pharmacotherapy is the most effective strategy in helping people to quit. However, there is no evidence for the effectiveness of this strategy in TB patients who smoke. We will assess the safety, effectiveness and cost-effectiveness of cytisinea low-cost plant-derived nicotine substitutefor smoking cessation in TB patients compared with placebo, over and above brief behavioural support. Design Two-arm, parallel, double-blind, placebo-controlled, multi-centre (30 sites in Bangladesh and Pakistan), individually randomized trial. Setting TB treatment centres integrated into public health care systems in Bangladesh and Pakistan. Participants Newly diagnosed (in the last 4weeks) adult pulmonary TB patients who are daily smokers (with or without dual smokeless tobacco use) and are interested in quitting (n=2388). Measurements The primary outcome measure is biochemically verified continuous abstinence from smoking at 6 months post-randomization, assessed using Russell Standard criteria. The secondary outcome measures include continuous abstinence at 12 months, lapses and relapses; clinical TB outcomes; nicotine dependency and withdrawal; and adverse events. Comments This is the first smoking cessation trial of cytisine in low- and middle-income countries evaluating both cessation and TB outcomes. If found effective, cytisine could become the most affordable cessation intervention to help TB patients who smoke.