title: International variation in the definition of 'main condition' in ICD-coded health data.
abstract: Hospital-based medical records are abstracted to create International Classification of Disease (ICD) coded discharge health data in many countries. The 'main condition' is not defined in a consistent manner internationally. Some countries employ a 'reason for admission' rule as the basis for the main condition, while other countries employ a 'resource use' rule. A few countries have recently transitioned from one of these approaches to the other. The definition of 'main condition' in such ICD data matters when it is used to define a disease cohort to assign diagnosis-related groups and to perform risk adjustment. We propose a method of harmonizing the international definition to enable researchers and international organizations using ICD-coded health data to aggregate or compare hospital care and outcomes across countries in a consistent manner. Inter-observer reliability of alternative harmonization approaches should be evaluated before finalizing the definition and adopting it worldwide.
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Quan
authors.affiliation: Canadian Institute for Health Information, Ottawa, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Moskal
authors.affiliation: Ottawa Hospital Research Institute and Institute for Clinical Evaluative Sciences, Ottawa, Canada.
authors.forename: A J
authors.initials: AJ
authors.lastname: Forster
authors.affiliation: Health Council of Canada, Toronto, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Brien
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Walker
authors.affiliation: Departments of Internal Medicine and Pediatrics, and Center for Healthcare Policy and Research, University of California Davis, Davis, USA.
authors.forename: P S
authors.initials: PS
authors.lastname: Romano
authors.affiliation: Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, Australia Department of Medicine, Southern Clinical School, Monash University, Melbourne, Australia.
authors.forename: V
authors.initials: V
authors.lastname: Sundararajan
authors.affiliation: Institut Universitaire de Médecine Sociale et Préventive, Centre, Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Burnand
authors.affiliation: Nordic WHO FIC Collaborating Centre, Oslo, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Henriksson
authors.affiliation: Nordic WHO FIC Collaborating Centre, Oslo, Norway.
authors.forename: O
authors.initials: O
authors.lastname: Steinum
authors.affiliation: Faculty of Industrial Engineering and Health Care, Niederrhein University of Applied Sciences, Reinarzstrasse 49, Krefeld, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Droesler
authors.affiliation: Department of Psychiatry, Columbia University College of Physicians and Surgeons, Division of Clinical Phenomenology, New York, NY, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Pincus
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Canada Department of Medicine, University of Calgary, Calgary, Canada.
authors.forename: W A
authors.initials: WA
authors.lastname: Ghali
mesh_terms: D059019:Clinical Coding / Q000592:standards*; D006739:Hospital Administration / Q000592:standards*; D006801:Humans; D038801:International Classification of Diseases / Q000592:standards*; D038622:Internationality; D015203:Reproducibility of Results
keywords: benchmarking; international classification of disease; measurement of quality; standards