Cost-effectiveness of tobacco cessation support combined with tuberculosis screening among contacts who smoke

SETTING: Tobacco smoking is associated with significantly increased risks of latent tuberculous infection, active tuberculosis (TB), TB recurrence and mortality. Tobacco cessation interventions not only increase health benefits, they also reduce the risk of TB. OBJECTIVE: To assess the cost-effectiveness of nicotine replacement therapy (NRT) combined with TB screening strategies using interferon-gamma release assays (IGRAs; QuantiFERON (R)-TB Gold In-Tube [OFT] and T-SPOT (R).TB [T-SPOT]) and comparing these with the tuberculin skin test (TST) among TB contacts who smoke. DESIGN: Decision trees and Markov models were constructed from a public health perspective. The target population was a hypothetical cohort of 20-year-old contacts who smoke until the age of 70 years, with or without NRT. The main outcome measure of effectiveness was quality-adjusted life-years (QALYs). The incremental cost-effectiveness ratio was compared. RESULTS: QFT alone led to lower costs but fewer QALYs. TST alone and TST+NRT were absolutely dominated. IGRAs+NRT yielded greater benefits than IGRAs alone, and T-SPOT+NRT yielded the greatest benefits. Cost-effectiveness was sensitive to NRT effectiveness and rate of mortality reduction using NRT. CONCLUSION: TB screening using an IGRA combined with NRT is more cost-effective among contacts who smoke. Positive smoking cessation interventions are recommended for their cost-effectiveness in low-incidence countries.