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

Abstract

SUMMARY 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.

Factors That Influence Treatment Completion for Latent Tuberculosis Infection

“…Our study demonstrates that people receiving charity care are less likely than those with private insurance to complete treatment, which is consistent with the findings of other studies. 20,25 Among the subjects who initiated treatment in 2013 or later, the Affordable Care Act had made insurance more broadly available to all but undocumented immigrants. Washington State, where this study was done, expanded Medicaid, and so by 2013 the majority of patients were insured.…”

“…16 -20 This is particularly important to consider with the newer DOT therapies available. Homelessness, 13,20 alcohol use, 13 and intravenous drug use 21 also all seem to be associated with noncompletion. While some studies demonstrate an impact of age on completion, with younger patients less likely to complete therapy, 13 others failed to replicate this finding.…”

“…13 One study demonstrated that men are more likely to complete therapy than women. 20 However, most of these studies were completed before the approval and wide use of the 3-month isoniazid and rifapentine regimen and before the increasing use of the 4-month daily rifampin regimen, and thus do not provide information on the challenges of additional treatment options.…”

Diagnosis and management of latent tuberculosis

“…Because of the long duration of treatment and the perceived adverse effects, compliance with INH monotherapy regimens is low, with adherence rates reported in the range of 44-69% [51,52]. A recent prospective multicenter cohort study in the United States and Canada found a completion rate of 46.5% for those prescribed 9 months of INH and 50% for those prescribed 6 months [53]. Poor compliance significantly reduces the effectiveness of these regimens.…”

Contact investigation outcomes of Canadian-born adults with tuberculosis in Indigenous and non-Indigenous populations in Alberta

“…Furthermore, the relatively poor outcomes of contact investigation for off-reserve Indigenous cases may be related to more frequent association with inner-city populations in the major cities of the province, changes of address/mobility, or lack of prioritization of tuberculosis as a health concern. 18,20,21 As potential solutions, social network analysis, geographic information systems and genomics have been recommended for enhancing TB contact investigations in population groups with increased mobility and who are underhoused. 18 However, real-time use of genomics is costly and not widely available, and use of this approach provides retrospective insight into outbreaks rather than preventing transmission from a case.…”