title: Overview of the special supplement issue.
authors.forename: M B
authors.initials: MB
authors.lastname: McClellan
authors.forename: J P
authors.initials: JP
authors.lastname: Newhouse
mesh_terms: D003625:Data Collection / Q000379:methods; D003627:Data Interpretation, Statistical; D006302:Health Services Research / Q000379:methods*; D006801:Humans; D017059:Models, Econometric; D017063:Outcome Assessment, Health Care / Q000379:methods*; D012107:Research Design