title: Finding high quality, efficient providers for value purchasing: cohort methods better than methods based on events.
authors.forename: John E
authors.initials: JE
authors.lastname: Wennberg
authors.forename: Elliott S
authors.initials: ES
authors.lastname: Fisher
mesh_terms: D015331:Cohort Studies; D017598:Efficiency, Organizational / Q000191:economics; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D007902:Length of Stay; D017063:Outcome Assessment, Health Care / Q000379:methods* / Q000592:standards; D019984:Quality Indicators, Health Care / Q000592:standards*