Adherence to treatment of latent tuberculosis infection in a clinical population in New York City.

BACKGROUND

Low adherence to treatment of latent tuberculosis infection (TLTBI) diminishes TB prevention efforts. This study examined the treatment completion rate among those who started TLTBI and factors associated with adherence to TLTBI.

METHODS

Patients who started TLTBI in New York City (NYC) Health Department chest clinics during January 2002-August 2004 were studied. TLTBI completion rate were described and compared according to patient demographic and clinical characteristics by regimen using univariate analysis and log-binomial regression.

RESULTS

A total of 15 035 patients started and 6788 (45.2%) completed TLTBI. Treatment completers were more likely than non-completers to be >or=35 years old (52.5%, adjusted relative risk (aRR)=1.2, 95% confidence interval (CI)=1.1, 1.2), contacts to pulmonary TB patients (57.4%, aRR=1.5, 95% CI=1.4, 1.7), treated by directly observed preventive therapy (DOPT) (71.4%, aRR=1.3, 95% CI=1.2, 1.3), and to have received the rifamycin-based regimen (60.0%, aRR=1.2, 95% CI=1.1, 1.3). The completion rate with an isoniazid regimen did not differ between HIV-infected and HIV-uninfected persons. Among those who failed to complete, 3748 (47.8%) failed to return for isoniazid and 59 (14.7%) for rifamycin after the first month of medication dispensing.

CONCLUSIONS

Shorter regimen and DOPT increased completion rates for LTBI. Though efforts to improve TLTBI completion need to address all groups, greater focus is needed for persons who are contacts and HIV-infected, as they have higher risk of developing TB.