Izabela E. Fedyszyn¹, Meredith G. Harris², Jo Robinson³, Susan J. Paxton¹

1 School of Psychological Science, La Trobe University, Melbourne, Victoria, Australia
2 School of Population Health, The University of Queensland, Brisbane, Queensland,
Australia
3 Orygen Youth Health Research Centre, Melbourne, Victoria, Australia

Crisis, Volume 33(3), 2012

Abstract

Background: One methodological difficulty for research into suicide attempts and suicide is distinguishing these phenomena from non-suicidal self-harming behaviors and accidents.  This is problematic because a reliable assessment of the presence or absence of the outcome variable is fundamental for the validity of the findings.  Aims: To develop a standardized rating system, the Classification Algorithm for the Determination of Suicide Attempt and Suicide (CAD-SAS), and to investigate its psychometric properties.  Methods: To examine the test-retest reliability, one investigator rated 217 narratives of real-life self-harming incidents at initial assessment and four weeks later.  To establish the inter-rater reliability, three independent raters assessed a random sample of 70 narratives using the CAD-SAS.  To examine the validity, ratings made by one investigator using the CAD-SAS were compared to clinical judgments made by a consultant psychiatrist without the CAD-SAS on the same random set of 70 narratives.  Results: Test-retest reliability was excellent (97.2% agreement) and inter-rater reliability was substantial (70.0% agreement, kappa = 0.70).  Agreement in the classification of incidents with the “real world” clinical judgments supports the validity of the CAD-SAS (64.3% agreement, kappa = 0.46).  Conclusions: Reliability and validity of future studies can be enhanced through the standardized assessment and classification of incidents.

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Author’s Note
The Classification Algorithm for the Determination of Suicide Attempt and Suicide (CAD-SAS) incorporates a set of guidelines for assessment and classification of incidents of self-harming behaviour, an incident rating form, and a training package. If you are interested in using the CAD-SAS for research or clinical purposes, please direct enquiries to: