The Accuracy of the Uganda National Tuberculosis and Leprosy Program algorithm and the World Health Organisation treatment decision algorithms for childhood tuberculosis: A retrospective analysis

Diagnosing childhood pulmonary tuberculosis (TB) is a challenge, and this led the Uganda National Tuberculosis and Leprosy Program (NTLP) to develop a clinical treatment decision algorithm (TDA) for children. However, there is limited data on its accuracy and how it compares to new World Health Organization (WHO) TB TDAs for children. This study aimed to evaluate and compare the accuracy of the 2017 Uganda NTLP algorithm with the 2022 WHO TDAs for TB among children in Kampala, Uganda. We retrospectively assessed children <15 years old who underwent an evaluation for TB between November 2018 and November 2022. Children were classified as per National Institutes of Health (NIH) consensus definitions. We applied the 2017 Uganda NTLP and 2022 WHO algorithms (A with chest x-ray [CXR], B without CXR) to make a decision to treat for TB or not, and calculated accuracy in reference to Confirmed vs. Unlikely TB, as well as a microbiological and composite reference standard. We compared accuracy of the Uganda NTLP algorithm to the WHO TDAs among children <10 years old. A total of 699 children were included in this analysis with 64% (451/699) under 5 years, 53% (373/669) were male, 12% (85/699) were Xpert Ultra positive, 11% (74/669) were HIV positive and 6% had severe acute malnutrition (SAM). The Uganda NTLP algorithm had a sensitivity of 97.9% (95% CI: 96.4-99.4) and specificity of 25.9% (95% CI: 21.2-30.7). If CXR was considered unavailable, sensitivity was 97.9% (95% CI: 96.4-99.4) and specificity 28.1% (95% CI: 23.2-33.0). Accuracy remained similar among high-risk children. In comparison, WHO TDAs had similar sensitivity to the Uganda NTLP, but algorithm A was more specific (32.2%, 95% CI: 26.9-37.5) and algorithm B was less specific (15.4%, 95% CI: 11.3-19.5). Both the Uganda NTLP and WHO TDAs had high sensitivity but low specificity. The WHO TDAs had better specificity than the NTLP algorithm with CXR, and worse specificity without CXR. Further optimization of the algorithms is needed to improve specificity and reduce over-treatment of TB in children.