Fig 2. Impact of the Xpert Ultra trace call.

Shown are expected primary outcomes under different scenarios for use of the trace call: trace results treated as negative (“without trace call,” red bars), trace results treated as positive only for those with no history of previous TB (“conditional trace call,” light red bars), trace results repeated and treated as positive only if the repeat result is trace or fully positive (“positive trace repeated,” light blue bars), or trace results treated as positive (“with trace call,” the primary analysis, dark blue bars). Bar graphs show the median over 5,000 simulations comparing standard Xpert to Ultra, and error bars show the interquartile range (25th and 75th percentile) of simulations; where no upper error bar is shown, no deaths were prevented in >25% of simulations. Treating the trace call as positive increased both incremental deaths averted and incremental unnecessary treatments but had little impact on the ratio of these 2 outcomes. TB, tuberculosis; Xpert, Xpert MTB/RIF.