Should we consider a ‘fourth 90’ for tuberculosis?

The international community has committed to end the tuberculosis (TB) epidemic by 2030. To facilitate the meeting of the global incidence and mortality indicators set by the World Health Organization's End TB Strategy, the Stop TB Partnership launched the three 90-(90)-90 diagnostic and treatment targets in 2014. In this paper, we argue that a 'fourth 90'-Ensuring that 90% of all people successfully completing treatment for TB can have a good health-related quality of life'-should be considered. Many individuals who successfully complete anti-TB treatment are burdened with lifelong comorbidities-human immunodeficiency virus (HIV) and diabetes mellitus, obstructive and restrictive lung disease, involving lung destruction, cavitation, fibrosis and bronchiectasis, that either pre-existed or developed as a result of TB (e.g., chronic pulmonary aspergillosis), permanent disabilities such as hearing loss resulting from second-line anti-TB drugs, and mental health disorders. These need to be identified during TB treatment and appropriate care and support provided after anti-TB treatment is successfully completed. A 'fourth 90' has also been proposed for the UNAIDS 90-90-90 targets similar in scope to what is being suggested here for TB. Adoption by both HIV and TB control programmes would highlight the current focus on integrated person- and family-centred services.