Treatment of latent TB infection (LTBI) is essential for preventing TB in North America, but acceptance and completion of this treatment have not been systematically assessed.
We performed a retrospective, randomized two-stage cross-sectional survey of treatment and completion of LTBI at public and private clinics in 19 regions of the United States and Canada in 2002.
At 32 clinics that both performed tuberculin skin testing and offered treatment, 123 (17.1%; 95% CI, 14.5%-20.0%) of 720 subjects tested and offered treatment declined. Employees at health-care facilities were more likely to decline (odds ratio [OR], 4.74; 95% CI, 1.75-12.9; P = .003), whereas those in contact with a patient with TB were less likely to decline (OR, 0.19; 95% CI, 0.07-0.50; P = .001). At 68 clinics starting treatment regardless of where skin testing was performed, 1,045 (52.7%; 95% CI, 48.5%-56.8%) of 1,994 people starting treatment failed to complete the recommended course. Risk factors for failure to complete included starting the 9-month isoniazid regimen (OR, 2.08; 95% CI, 1.23-3.57), residence in a congregate setting (nursing home, shelter, or jail; OR, 2.94; 95% CI, 1.58-5.56), injection drug use (OR, 2.13; 95% CI, 1.04-4.35), age ≥ 15 years (OR, 1.49; 95% CI, 1.14-1.94), and employment at a health-care facility (1.37; 95% CI, 1.00-1.85).
Fewer than half of the people starting treatment of LTBI completed therapy. Shorter regimens and interventions targeting residents of congregate settings, injection drug users, and employees of health-care facilities are needed to increase completion.