title: Immigrant screening for latent tuberculosis in Norway: a cost-effectiveness analysis.
abstract: The incidence of tuberculosis (TB) disease has increased in Norway since the mid-1990s. Immigrants are screened, and some are treated, for latent TB infection (LTBI) to prevent TB disease (reactivation). In this study, we estimated the costs of both treating and screening for LTBI and TB disease, which has not been done previously in Norway. We developed a model to indicate the cost-effectiveness of four different screening algorithms for LTBI using avoided TB disease cases as the health outcome. Further, we calculated the expected value of perfect information (EVPI), and indicated areas of LTBI screening that could be changed to improve cost-effectiveness. The costs of treating LTBI and TB disease were estimated to be €1938 and €15,489 per case, respectively. The model evaluates four algorithms, and suggests three cost-effective algorithms depending on the cost-effectiveness threshold. Screening all immigrants with interferon-gamma release assays (IGRA) requires the highest threshold (€28,400), followed by the algorithms "IGRA on immigrants with risk factors" and "no LTBI screening." EVPI is approximately €5 per screened immigrant. The costs for a cohort of 20,000 immigrants followed through 10 years range from €12.2 million for the algorithm "screening and treatment for TB disease but no LTBI screening," to €14 million for "screening all immigrants for both TB disease and LTBI with IGRA." The results suggest that the cost of TB disease screening and treatment is the largest contributor to total costs, while LTBI screening and treatment costs are relatively small. Increasing the proportion of IGRA-positive immigrants who are treated decreases the costs per avoided case substantially.
authors.affiliation: Domain for Infection Control and Environmental Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, Oslo, Norway. fredrikhaukaas@gmail.com.|Department of Health Management and Health Economics, Institute for Health and Society, University of Oslo, Postboks 1089, 0317, Blindern, Norway. fredrikhaukaas@gmail.com.
authors.forename: Fredrik Salvesen
authors.initials: FS
authors.lastname: Haukaas
authors.affiliation: Domain for Infection Control and Environmental Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, Oslo, Norway.
authors.forename: Trude Margrete
authors.initials: TM
authors.lastname: Arnesen
authors.affiliation: Domain for Infection Control and Environmental Health, Norwegian Institute of Public Health, PO Box 4404 Nydalen, Oslo, Norway.
authors.forename: Brita Askeland
authors.initials: BA
authors.lastname: Winje
authors.affiliation: Department of Health Management and Health Economics, Institute for Health and Society, University of Oslo, Postboks 1089, 0317, Blindern, Norway.
authors.forename: Eline
authors.initials: E
authors.lastname: Aas
mesh_terms: D000465:Algorithms; D000995:Antitubercular Agents / Q000191:economics / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D054242:Emigrants and Immigrants; D017048:Health Care Costs / Q000706:statistics & numerical data; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000191:economics; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000188:drug therapy / Q000191:economics*; D009664:Norway; D018570:Risk Assessment / Q000379:methods; D014374:Tuberculin Test / Q000191:economics; D014376:Tuberculosis / Q000175:diagnosis / Q000188:drug therapy / Q000191:economics
chemical_list: D000995:Antitubercular Agents
keywords: CEA; Cost-effectiveness analysis; EVPI; Economic evaluation; Expected value of perfect information; IGRA; Immigrants; Interferon gamma release assay; Latent tuberculosis; Norway; Screening; TST; Tuberculin skin test; Tuberculosis