title: Assessing disability weights based on the responses of 30,660 people from four European countries.
abstract: BACKGROUND
  In calculations of burden of disease using disability-adjusted life years, disability weights are needed to quantify health losses relating to non-fatal outcomes, expressed as years lived with disability. In 2012 a new set of global disability weights was published for the Global Burden of Disease 2010 (GBD 2010) study. That study suggested that comparative assessments of different health outcomes are broadly similar across settings, but the significance of this conclusion has been debated. The aim of the present study was to estimate disability weights for Europe for a set of 255 health states, including 43 new health states, by replicating the GBD 2010 Disability Weights Measurement study among representative population samples from four European countries.
  
  
  METHODS
  For the assessment of disability weights for Europe we applied the GBD 2010 disability weights measurement approach in web-based sample surveys in Hungary, Italy, Netherlands, and Sweden. The survey included paired comparisons (PC) and population health equivalence questions (PHE) formulated as discrete choices. Probit regression analysis was used to estimate cardinal values from PC responses. To locate results onto the 0-to-1 disability weight scale, we assessed the feasibility of using the GBD 2010 scaling approach based on PHE questions, as well as an alternative approach using non-parametric regression.
  
  
  RESULTS
  In total, 30,660 respondents participated in the survey. Comparison of the probit regression results from the PC responses for each country indicated high linear correlations between countries. The PHE data had high levels of measurement error in these general population samples, which compromises the ability to infer ratio-scaled values from discrete choice responses. Using the non-parametric regression approach as an alternative rescaling procedure, the set of disability weights were bounded by distance vision mild impairment and anemia with the lowest weight (0.004) and severe multiple sclerosis with the highest weight (0.677).
  
  
  CONCLUSIONS
  PC assessments of health outcomes in this study resulted in estimates that were highly correlated across four European countries. Assessment of the feasibility of rescaling based on a discrete choice formulation of the PHE question indicated that this approach may not be suitable for use in a web-based survey of the general population.
authors.affiliation: Department of Public Health, Erasmus MC, P.O. Box 2040, , 3000, CA Rotterdam, The Netherlands ; Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA.
authors.forename: Juanita A
authors.initials: JA
authors.lastname: Haagsma
authors.affiliation: Institute of Health and Society (IRSS), Université catholique de Louvain, Leuven, Belgium.
authors.forename: Charline
authors.initials: C
authors.lastname: Maertens de Noordhout
authors.affiliation: Department of Public Health, Erasmus MC, P.O. Box 2040, , 3000, CA Rotterdam, The Netherlands.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Polinder
authors.affiliation: Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA.
authors.forename: Theo
authors.initials: T
authors.lastname: Vos
authors.affiliation: National Institute for Public Health and the Environment, Centre for Infectious Disease Control, Bilthoven, the Netherlands ; Emerging Pathogens Institute, University of Florida, Gainesville, Florida USA ; Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands.
authors.forename: Arie H
authors.initials: AH
authors.lastname: Havelaar
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm, Sweden.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cassini
authors.affiliation: Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Brecht
authors.initials: B
authors.lastname: Devleesschauwer
authors.affiliation: National Institute for Public Health and the Environment, Centre for Infectious Disease Control, Bilthoven, the Netherlands ; Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Mirjam E
authors.initials: ME
authors.lastname: Kretzschmar
authors.affiliation: Institute of Health and Society (IRSS), Université catholique de Louvain, Leuven, Belgium.
authors.forename: Niko
authors.initials: N
authors.lastname: Speybroeck
authors.affiliation: Department of Global Health and Population, Harvard School of Public Health, Boston, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Salomon
keywords: Disability adjusted life years; Disability weight; Disease burden; Prioritisation; Summary measure of population health; Value of life