title: Modeling the impact of tuberculosis interventions on epidemiologic outcomes and health system costs.
abstract: BACKGROUND
  Tuberculosis (TB) programs must invest in a variety of TB specific activities in order to reach ambitious global targets. Uncertainty exists surrounding the potential impact of each of these activities. The objective of our study was to model different interventions and quantify their impact on epidemiologic outcomes and costs from the health system perspective.
  
  
  METHODS
  Decision analysis was used to define the TB patient trajectory within the health system of three different countries. We considered up to seven different interventions that could affect either the natural history of TB, or patient trajectories within the health system. The expected impact of interventions were derived from published studies where possible. Epidemiologic outcomes and associated health system costs were projected for each scenario.
  
  
  RESULTS
  With no specific intervention, TB related death rates are high and less than 10% of the population starts on correct treatment. Interventions that either prevent cases or affect all patients with TB disease early in their trajectory are expected to have the biggest impact, regardless of underlying epidemiologic characteristics of the setting. In settings with a private sector, improving diagnosis and appropriate treatment across all sectors is expected to have a major impact on outcomes.
  
  
  CONCLUSIONS
  In all settings, the greatest benefit will come from early diagnosis of all forms of TB. Once this has been achieved more specific interventions, such as those targeting HIV, drug resistance or the private sector can be integrated to increase impact.
authors.affiliation: McGill University and the McGill International TB Centre, Montreal, Canada. olivia.oxlade@mcgill.ca.
authors.forename: Olivia
authors.initials: O
authors.lastname: Oxlade
authors.affiliation: United States Agency for International Development, Washington, DC, USA. apiatek@usaid.gov.
authors.forename: Amy
authors.initials: A
authors.lastname: Piatek
authors.affiliation: United States Agency for International Development, Washington, DC, USA. cvincent@usaid.gov.
authors.forename: Cheri
authors.initials: C
authors.lastname: Vincent
authors.affiliation: McGill University and the McGill International TB Centre, Montreal, Canada. dick.menzies@mcgill.ca.|Montreal Chest Institute, 3650 St. Urbain St, Montréal, H2X 2P4, PQ, Canada. dick.menzies@mcgill.ca.
authors.forename: Dick
authors.initials: D
authors.lastname: Menzies
mesh_terms: D000328:Adult; D003661:Decision Support Techniques; D003695:Delivery of Health Care / Q000191:economics*; D005260:Female; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D038622:Internationality; D008297:Male; D008875:Middle Aged; D011634:Public Health; D014376:Tuberculosis / Q000453:epidemiology* / Q000517:prevention & control*