Latent tuberculous infection in the United States and Canada: who completes treatment and why?

OBJECTIVES: To assess latent tuberculous infection (LTBI) treatment completion rates in a large prospective US/Canada multisite cohort and identify associated risk factors.

METHODS: This prospective cohort study assessed factors associated with LTBI treatment completion through interviews with persons who initiated treatment at 12 sites. Interviews were conducted at treatment initiation and completion/cessation. Participants received usual care according to each clinic's procedure. Multivariable models were constructed based on stepwise assessment of potential predictors and interactions.

RESULTS: Of 1515 participants initiating LTBI treatment, 1323 had information available on treatment completion; 617 (46.6%) completed treatment. Baseline predictors of completion included male sex, foreign birth, not thinking it would be a problem to take anti-tuberculosis medication, and having health insurance. Participants in stable housing who received monthly appointment reminders were more likely to complete treatment than those without stable housing or without monthly reminders. End-of-treatment predictors of non-completion included severe symptoms and the inconvenience of clinic/pharmacy schedules, barriers to care and changes of residence. Common reasons for treatment non-completion were patient concerns about tolerability/toxicity, appointment conflicts, low prioritization of TB, and forgetfulness.

CONCLUSIONS: Less than half of treatment initiators completed treatment in our multisite study. Addressing tangible issues such as not having health insurance, toxicity concerns, and clinic accessibility could help to improve treatment completion rates.