Background: There is renewed attention to the critical role of successfully treating latent tuberculosis infection (LTBI) in reducing the overall impact of tuberculosis (TB). However, levels of treatment adherence are consistently low in industrialized countries such as the United States and Canada.
Objective: A systematic review of studies in the US and Canada was undertaken to analyze measurement of adherence to treatment of LTBI (TLTBI), TLTBI completion rates, predictors of TLTBI adherence and TLTBI adherence interventions.
Methods: PUBMED, MEDLINE and PsycINFO electronic databases were searched for quantitative studies published between 1997 and 2007. Full texts of articles were reviewed for data abstraction and studies were critically examined for their methodology and rigor. The present review presents outcomes from 78 studies.
Results: Adherence and completion rates of TLTBI are suboptimal across high-risk groups, regardless of regimen. Associations between adherence and patient factors, clinic facilities or treatment characteristics were found to be inconsistent across studies. Several adherence interventions have been developed to improve TLTBI adherence in the US and Canada; however, no single intervention has shown consistent effectiveness.
Conclusion: LTBI must be effectively treated if the goal of TB elimination is to be realized. Consistently employing tools for measuring and improving adherence is fundamental. Identifying barriers to adherence and treatment completion will facilitate the development of effective, appropriate interventions. A 'one-size-fits-all' approach to treatment for TLTBI adherence is not likely to succeed across all settings. Innovative approaches can inspire future interventions and suggest solutions for the current problems facing LTBI programs and their patients.