Predicting non-completion of treatment for latent tuberculous infection: a prospective survey

Treatment of latent tuberculosis (TB) infection (LTBI) is essential for the elimination of TB in the United States, but treatment is often not completed. Little is known about patients' reasons for not completing treatment. We hypothesized that certain health beliefs, lifestyle, and clinic- and regimen-related barriers to provision of care could predict non-completion of LTBI treatment.

We administered a survey in English, Chinese, or Spanish to patients with LTBI at the first TB clinic visit. Using chi(2) and logistic regression analysis, we assessed demographics, TB risk factors, and survey responses as predictors of non-completion of 6 mo of isoniazid.

217 patients, 90% foreign-born, completed the survey, and 28.6% of which finished at least 6 mo of isoniazid under usual clinic conditions. Multivariate analysis identified two independent predictors of non-completion: low risk perception of progressing to active TB without LTBI treatment (odds ratio [OR], 0.31 [0.13-0.72], 95% confidence interval [CI]), p = 0.007, accounting for 20% of non-completers, and not wanting venipuncture (OR, 0.43 [0.22-0.85], 95% CI), p = 0.015, accounting for 37% of non-completers. Another 18% shared both predictors; thus these two predictors accounted for 75% of non-completers in total.

Patients assess LTBI treatment risks and inconveniences relative to low perceived benefits at treatment outset. Predictors of LTBI treatment non-completion are identifiable at the first visit. Targeting TB high-risk individuals, minimizing inconveniences, further education, and use of diagnostic tests with improved specificity for TB may address these concerns.