Article

Analysis of risk factors for schizophrenia with two different case definitions: A nationwide register-based external validation study

Schizophrenia Research, Elsevier, ISSN 0920-9964

Volume 162, 1-3, 2015

DOI:10.1016/j.schres.2015.01.018, Dimensions: pub.1019484823, PMID: 25620118,

Authors

Mors, Ole (1) (4)

* Corresponding author

Affiliations

Organisations

  1. (1) Lundbeck Foundation, grid.452548.a
  2. (2) Mental Health Services, grid.466916.a, Central Denmark Region
  3. (3) Aarhus University, grid.7048.b, AU
  4. (4) Aarhus University Hospital, grid.154185.c, Central Denmark Region

Countries

Denmark

Continents

Europe

Description

Different case definitions of schizophrenia have been used in register based research. However, no previous study has externally validated two different case definitions of schizophrenia against a wide range of risk factors for schizophrenia. We investigated hazard ratios (HRs) for a wide range of risk factors for ICD-10 DCR schizophrenia using a nationwide Danish sample of 2,772,144 residents born in 1955-1997. We compared one contact only (OCO) (the case definition of schizophrenia used in Danish register based studies) with two or more contacts (TMC) (a case definition of at least 2 inpatient contacts with schizophrenia). During the follow-up, the OCO definition included 15,074 and the TMC 7562 cases; i.e. half as many. The TMC case definition appeared to select for a worse illness course. A wide range of risk factors were uniformly associated with both case definitions and only slightly higher risk estimates were found for the TMC definition. Choosing at least 2 inpatient contacts with schizophrenia (TMC) instead of the currently used case definition would result in almost similar risk estimates for many well-established risk factors. However, this would also introduce selection and include considerably fewer cases and reduce power of e.g. genetic studies based on register-diagnosed cases only.

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Aarhus University

Danish Open Access Indicator

2015: Unused

Research area: Medicine

Danish Bibliometrics Indicator

2015: Level 1

Research area: Medicine

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Times Cited: 5

Field Citation Ratio (FCR): 1.39

Relative Citation ratio (RCR): 0.33