[Comment] Tuberculosis and undernutrition: improving estimates to reinforce the policy imperative

Undernutrition is a key driver of the global tuberculosis epidemic, increasing the risk of people developing tuberculosis disease and of poor outcomes in those who do.1 Each year, WHO publishes estimates of the number of tuberculosis disease episodes attributable to undernutrition and other risk factors, based on population attributable fractions (PAFs). These PAF values allow stakeholders to compare the relative role of different risk factors in the tuberculosis epidemic, shaping policy and setting research agendas.