Treatment Outcomes and Loss to Follow-Up in Tuberculosis: A Real-World Cohort Study from Sicily, Italy

Abstract Background Tuberculosis (TB) remains a major cause of morbidity and mortality worldwide. Its management is frequently complicated by prolonged treatment, drug-related toxicity, antimicrobial resistance, and difficulties in maintaining long-term follow-up. We aimed to describe the clinical characteristics, management, and treatment outcomes of patients with TB treated at a tertiary referral center in Sicily, Italy. Methods We conducted a retrospective observational study of consecutive patients with TB managed between January 2021 and December 2023. Demographic, clinical, microbiological, treatment-related, and outcome data were collected. Outcomes included treatment completion, loss to follow-up (LTFU), transfer to another center, treatment failure, relapse, and death. Factors associated with treatment completion were evaluated using multivariable logistic regression. Results Among 164 patients, 130 (79.2%) were male, and 105 (64.0%) were born outside Italy. Pulmonary TB was diagnosed in 141 patients (86.0%), including 82 (58.2%) with concomitant extrapulmonary involvement. Microbiological confirmation was obtained in 106 (64.6%). Phenotypic drug susceptibility testing was available for 50 patients, of whom 17 (34.0%) showed resistance to at least one drug tested. Adverse drug reactions occurred in 37 patients (22.6%), most commonly hepatotoxicity, and led to treatment modification in 35. By the end of follow-up, 95 patients (57.9%) had completed treatment, 53 (32.3%) were LTFU, 5 (3.0%) had been transferred to another center, and 11 (6.7%) had died. Treatment failure and relapse were each documented in one patient. Five deaths were directly attributable to TB, whereas six were related to underlying or concomitant comorbidities. Foreign-born status was independently associated with lower likelihood of treatment completion (adjusted OR, 0.260; 95% CI, 0.106–0.641; p = 0.003). Conclusions In this real-world cohort, TB management was characterized by substantial clinical complexity and a high rate of LTFU. Foreign-born patients were significantly less likely to complete treatment, underscoring the need for patient-centered strategies to strengthen long-term engagement and reduce LTFU.