Causes of pre-treatment loss to follow-up in patients with TB.

Setting: Five urban TB diagnostic centres in Lusaka, Zambia.

Objective: To determine the proportion of bacteriologically confirmed pre-treatment lost to follow-up (LTFU) patients with TB found at the study settings in 2020.

Design: This was a retrospective cohort study in which the TB laboratory and treatment registers at the study sites were cross-matched.

Results: A total of 1,085 bacteriologically confirmed patients with TB were found in the laboratory TB registers at the study settings. Of these, 809 (74.6%) were males, whereas 8 (0.7%) were children, 1,005 (92.6%) were diagnosed using Xpert, 78 (7.2%) by microscopy. A total of 91 (8.4%, 95% CI 6.8-10.2) were determined to be pre-treatment LTFU. Those who had very low (14.0%, 95% CI 8.5-21.2) and low (11.8%, 95% CI 8.4-16.0) results on Xpert were respectively 3.1 (95% CI 1.6-6.0) and 2.6 (95% CI 1.4-4.8) times more likely to become pre-treatment LTFU than those who had medium (4.5%, 95% CI 2.5-7.4) results. The proportions of pre-treatment LTFU varied among the study sites from 0.7% to 16.1%.

Conclusion: Health facilities should strive to account for every patient with TB, with particular attention to those who are bacteriologically confirmed.