Complete sputum smear monitoring among adults with pulmonary tuberculosis in central Uganda: evidence from a retrospective cohort study

People with bacteriologically confirmed pulmonary tuberculosis require sputum smear monitoring at 2, 5, and 6 months to establish treatment outcomes. However, there is limited information about sputum smear monitoring in Uganda, similar to other developing countries. We examined factors associated with complete sputum smear monitoring among persons with bacteriologically confirmed pulmonary TB aged ≥ 15 years in central Uganda.

We retrospectively reviewed and abstracted data for persons with bacteriologically confirmed pulmonary TB initiated on treatment between January 2017 and December 2019 across 11 large TB units in Masaka district in central Uganda. Complete sputum smear monitoring was measured as the receipt of three sputum smear microscopy tests at 2, 5, and 6 months of TB treatment. The data were summarized descriptively and the differences in the outcome with independent variables were examined using tests of statistical significance, namely the Chi-square or Fisher’s exact test and the student’s t-test. The factors independently associated with the outcome were established using the modified Poisson regression analysis with robust standard errors, reported as adjusted risk ratio (aRR) along with the 95% confidence interval (CI).

A total of 416 participants were enrolled, with a mean age of 37.3 ± 12.9 years. Of the participants, 290 (69.7) were males, 269 (64.7) were rural residents, and 128 (30.8%) had complete sputum smear monitoring. Urban residence (aRR, 1.45; 95% CI 1.12–1.90) and treatment under the community-based directly observed therapy short-course strategy (DOTS) (aRR, 1.91; 95% CI 1.25–2.92) were associated with a higher likelihood of complete sputum smear monitoring while TB and human immunodeficiency virus (TB/HIV) comorbidity (aRR 0.45, 95% CI 0.30–0.68) was associated with a lower likelihood of complete sputum smear monitoring.

We found a low magnitude of complete sputum smear monitoring among persons with bacteriologically confirmed pulmonary TB aged ≥ 15 years in central Uganda. Strategies to enhance the performance of sputum smear monitoring should target rural health facilities, strengthen TB/HIV collaboration and the implementation of community-based DOTS.