Predictors of latent tuberculosis treatment initiation and completion at a U.S. public health clinic: a prospective cohort study

Abstract

BackgroundTreatment of latent tuberculosis infection (LTBI) is a key component in U.S. tuberculosis control, assisted by recent improvements in LTBI diagnostics and therapeutic regimens. Effectiveness of LTBI therapy, however, is limited by patients’ willingness to both initiate and complete treatment. We aimed to evaluate the demographic, medical, behavioral, attitude-based, and geographic factors associated with LTBI treatment initiation and completion of persons presenting with LTBI to a public health tuberculosis clinic.MethodsData for this prospective cohort study were collected from structured patient interviews, self-administered questionnaires, clinic intake forms, and U.S. census data. All adults (>17 years) who met CDC guidelines for LTBI treatment between January 11, 2008 and May 6, 2009 at Wake County Health and Human Services Tuberculosis Clinic in Raleigh, North Carolina were included in the study. In addition to traditional social and behavioral factors, a three-level medical risk variable (low, moderate, high), based on risk factors for both progression to and transmission of active tuberculosis, was included for analysis. Clinic distance and neighborhood poverty level, based on percent residents living below poverty level in a person’s zip code, were also analyzed. Variables with a significance level <0.10 by univariate analysis were included in log binomial models with backward elimination. Models were used to estimate risk ratios for two primary outcomes: (1) LTBI therapy initiation (picking up one month’s medication) and (2) therapy completion (picking up nine months INH therapy or four months rifampin monthly).Results496 persons completed medical interviews and questionnaires addressing social factors and attitudes toward LTBI treatment. 26% persons initiated LTBI therapy and 53% of those initiating completed therapy. Treatment initiation predictors included: a non-employment reason for screening (RR 1.6, 95% CI 1.0-2.5), close contact to an infectious TB case (RR 2.5, 95% CI 1.8-3.6), regular primary care(RR 1.4, 95% CI 1.0-2.0), and history of incarceration (RR 1.7, 95% CI 1.0-2.8). Persons in the “high” risk category for progression/transmission of TB disease had higher likelihood of treatment initiation (p < 0.01), but not completion, than those with lower risk.ConclusionsInvestment in social support and access to regular primary care may lead to increased LTBI therapy adherence in high-risk populations.

Completion Rate and Safety of Tuberculosis Infection Treatment With Shorter Regimens

“…3 Completion rates of <50% have been reported for both children and adults when TB medications are administered by families. 4,5 There are few patient-specific factors associated with completion of therapy. Our previous studies found that region of origin, language, and the method to test for TB infection (TST versus IGRA) were not associated with completion of therapy.…”

A prospective cohort study of latent tuberculosis in adult close contacts of active pulmonary tuberculosis patients in Korea

“…The acceptance and discontinuation rates of LTBI treatment vary. Only 26% of people identified with LTBI initiated their treatments in a study conducted at public health clinics in the United States; however, only 53% of them completed the treatment course [ 24 ]. Horsburgh [ 8 ] observed completion rates of 69% and 45% for 4RIF and 9INH among high-risk populations at public clinics.…”

Evaluation of Treatment Indications, Tuberculin Skin Test, and Bacillus Calmette-Guerin Vaccination Scars in the Cases of Latent Tuberculosis Infection Treatment

“…A prospective study showed that only 53% of patients completed the therapy [26]. Erkens et al [27] showed that of 1,049 children with LTBI started on LTBI treatment in 2005-2012, and 90% completed the treatment.…”