Breaking barriers: Implementation of a tuberculosis preventive treatment protocol among newly eligible populations with promising results

BACKGROUND: The World Health Organization emphasizes tuberculosis preventive treatment (TPT) as key to TB elimination. Implementation faces risk-benefit and adherence challenges. We implemented a structured TPT protocol at Hospital Gregorio Marañón with telephone support, personalized selection of currently available regimens, and toxicity management. OBJECTIVE: To assess the structured TPT protocol in achieving complete preventive treatment (CPT) and identify factors associated with non-completion (NCPT). METHODS: Retrospective analysis of a prospective cohort (2017-2024) of adults referred to the TB Unit. All causes of TPT were included per Spanish guidelines, except people living with HIV, who are followed in a separate clinic. Demographics, comorbidities, and outcomes were prospective collected. Univariate and multivariable logistic regression were used to identify predictors. RESULTS: Of 554 patients, 542 (97.8%) initiated TPT: close TB contacts (37.6%), immunosuppression (27.9%), and indications for immunomodulatory therapy (34.5%). Overall CPT was 86.5% (80.3% in those > 75 years; 90.7% in ages 35-54). Cancer predicted NCPT (aOR 2.25; 95% CI 1.21-4.21; p = 0.011). Among 73 NCPT cases, toxicity was the main cause (42.5%), followed by voluntary withdrawal (27.4%), social problems (20.5%, mainly in young immigrants), intercurrent disease (9.6%, notably cancer). Polypharmacy (aOR 2.51; 95% CI 1.13-5.60; p = 0.023) and inflammatory disease (aOR 2.25; 95% CI 1.06-4.75; p = 0.034) independently predicted toxicity-related NCPT. CONCLUSIONS: The structured TPT protocol was associated with high CPT rates (86.5%), with excellent safety. Cancer predicted NCPT, polypharmacy and inflammatory disease predicted toxicity leading to NCPT. Similar studies are needed to compare our results.