title: Data-driven methods for imputing national-level incidence in global burden of disease studies.
abstract: OBJECTIVE
  To develop transparent and reproducible methods for imputing missing data on disease incidence at national-level for the year 2005.
  
  
  METHODS
  We compared several models for imputing missing country-level incidence rates for two foodborne diseases - congenital toxoplasmosis and aflatoxin-related hepatocellular carcinoma. Missing values were assumed to be missing at random. Predictor variables were selected using least absolute shrinkage and selection operator regression. We compared the predictive performance of naive extrapolation approaches and Bayesian random and mixed-effects regression models. Leave-one-out cross-validation was used to evaluate model accuracy.
  
  
  RESULTS
  The predictive accuracy of the Bayesian mixed-effects models was significantly better than that of the naive extrapolation method for one of the two disease models. However, Bayesian mixed-effects models produced wider prediction intervals for both data sets.
  
  
  CONCLUSIONS
  Several approaches are available for imputing missing data at national level. Strengths of a hierarchical regression approach for this type of task are the ability to derive estimates from other similar countries, transparency, computational efficiency and ease of interpretation. The inclusion of informative covariates may improve model performance, but results should be appraised carefully.
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands .
authors.forename: Scott A
authors.initials: SA
authors.lastname: McDonald
authors.affiliation: Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium .
authors.forename: Brecht
authors.initials: B
authors.lastname: Devleesschauwer
authors.affiliation: Institute of Health and Society (IRSS), Université catholique de Louvain, Brussels, Belgium .
authors.forename: Niko
authors.initials: N
authors.lastname: Speybroeck
authors.affiliation: Centre for Statistics, Hasselt University, Diepenbeek, Belgium .
authors.forename: Niel
authors.initials: N
authors.lastname: Hens
authors.affiliation: Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium .
authors.forename: Nicolas
authors.initials: N
authors.lastname: Praet
authors.affiliation: Section of Veterinary Epidemiology, University of Zürich, Zürich, Switzerland .
authors.forename: Paul R
authors.initials: PR
authors.lastname: Torgerson
authors.affiliation: Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands .
authors.forename: Arie H
authors.initials: AH
authors.lastname: Havelaar
authors.affiliation: Department of Food Science and Human Nutrition, Michigan State University, East Lansing, United States of America (USA).
authors.forename: Felicia
authors.initials: F
authors.lastname: Wu
authors.affiliation: Food Animal Production Medicine Section, School of Veterinary Medicine UW-Madison, Madison, USA .
authors.forename: Marlène
authors.initials: M
authors.lastname: Tremblay
authors.affiliation: Food Animal Production Medicine Section, School of Veterinary Medicine UW-Madison, Madison, USA .
authors.forename: Ermias W
authors.initials: EW
authors.lastname: Amene
authors.affiliation: Food Animal Production Medicine Section, School of Veterinary Medicine UW-Madison, Madison, USA .
authors.forename: Dörte
authors.initials: D
authors.lastname: Döpfer
mesh_terms: D000348:Aflatoxins / Q000009:adverse effects; D001499:Bayes Theorem; D001699:Biometry / Q000379:methods*; D006528:Carcinoma, Hepatocellular / Q000453:epidemiology / Q000209:etiology; D016208:Databases, Factual; D005517:Foodborne Diseases / Q000453:epidemiology; D000071219:Global Burden of Disease / Q000379:methods*; D014943:Global Health; D006801:Humans; D015994:Incidence; D012044:Regression Analysis; D015203:Reproducibility of Results; D014125:Toxoplasmosis, Congenital / Q000453:epidemiology / Q000209:etiology
chemical_list: D000348:Aflatoxins