Suicide Risk Assessment Guide - Ontario Hospital Association

Box 4. Psychometric and Technical Considerations for Evaluating Suicide Risk Assessment Tools
Section II: Inventory Of Suicide Risk Assessment Tools
Correlation The extent of an association between variables (e.g., tool scores), such that when values in one
variable changes, so does the other. A correlation can range from -1.0 to 1.0. The closer the score is to
-1.0 or 1.0, the stronger the relationship between variables. Negative correlations indicate that as the
value in one variable increases the value in the second variable decreases. Correlation is often used
in the validation process when examining how well a tool’s score relates to other indicators or suicide
risk or distress.
Reliability The degree to which a risk assessment tool will produce consistent results (e.g., internal consistency)
at a different period (e.g., test-retest), or when completed by different assessors (e.g., inter-rater). A
common statistic reported for internal consistency is the Cronbach’s alpha (or α). This statistic, like a
correlation, ranges from 0 to 1.0. A higher score means the items consistently measure the construct
of interest. Typically, a score of 0.7 or higher indicates good reliability.
Validity The degree to which a risk assessment tool will measure what it is intended to measure or forecast
into the future. Convergent, concurrent, and construct validity may be established by looking at the
correlation between a tool’s score and scores of other instruments, measures, or factors already know
to measure or indicate the construct of interest (e.g., suicide risk assessment tool should correlate
with other gold standard instruments for measuring suicide risk or factors related to suicide risk
such as severe depression). Face validity can be established when the content of the instrument is in
agreement with the accepted theory or clinical dimensions of the construct of interest. Predictive
validity refers to how well a score on a suicide risk tool can predict future behaviour.
Sensitivity A component of validity, sensitivity of a risk assessment tool is the ability of the instrument to identify
correctly persons who are at risk.
Specificity A component of validity, specificity of a risk assessment tool is the ability of the instrument to identify
correctly those who are not at risk.
Factor
Analysis
Threshold
Scores
Modes of
Administration
A statistical approach that can be used to analyze interrelationships among a large number of items
on a tool and to explain these relationships in terms of their common underlying dimensions
(factors). Usually, this analysis is done to determine how items in an instrument measure a
similar factor.
A threshold score is the minimum score that denotes a level of risk on an assessment instrument.
Falling within a high range of points, for example, may suggest higher risk for suicide. Note that not
all threshold scores are validated across populations/settings and their use may result in increased
false negatives (i.e., incorrectly labeling a person not at risk of suicide). To adopt a threshold score for
identifying high risk of suicide, evidence of strong sensitivity and specificity, as described above,
is required.
Several approaches to risk assessment exist, such as a clinical interview or through a self-report
questionnaire. Advantages of self report include the opportunity for screening prior to a visit,
particularly in primary care or use as a break in the clinical interview and an opportunity for
corroboration. Disadvantages include the potential for perceived disconnect between the assessor and
person and the impersonal nature of completing the form.
Suicide Risk Assesment Guide I 37