Flow chart of diagnostic assessment and basis of TB treatment initiation in 641 TB suspects presenting to a primary care clinic in Johannesburg, South Africa.

The basis of diagnosis was defined as the earliest positive diagnostic test (smear, culture, Xpert or x-ray), or an empiric diagnosis if treatment was started in absence of or prior to any positive diagnostic test. Abbreviation: TB, tuberculosis; Neg, negative; Pos, positive; Cont, contaminated; NTM, non-tuberculous mycobacteria; ND, not done.