Abstract :
Background Kessler’s Psychological Distress
Scale (K10) is a ten-item measure of psychological
distress that has been used in recent epidemiological
research and as a screen for mental disorders. Moderate
relationships have been reported between the
K10 and measures of related constructs, such as diagnoses
of mental disorders and associated disability.
However, it is unclear whether the validity of the K10
is consistent across important demographic, cultural,
and socio-economic groups such as gender and educational
history or whether there is evidence of predictive
bias or inconsistency across these groups.
Methods Differential validity or predictive bias in the
relationship between K10 scores and disability days,
SF12 Mental Component Summary (MCS) scores, and
1-month Composite International Diagnostic Interview
(CIDI) diagnoses of the Diagnostic and Statistical
Manual of Mental Disorders, Fourth Edition (DSM-IV)
Anxiety and Depressive disorders due to gender and
completing secondary school were examined using
hierarchical linear and logistic regression analyses in
the Australian National Survey of Mental Health and
Wellbeing data set. Results Very small slope and/or
intercept biases in the relationship between the K10
and disability days, the SF12 MCS, and 1-month CIDI
diagnoses of anxiety and depression were found [effect
sizes, the ratio of variance explained to unexplained
variance (Cohen’s f2), varied from 0.0001 to 0.004].
Conclusion Gender and educational predictive biases
in the relationship between the K10 and disability days,
SF12 MCS, and 1-month diagnoses were found to be
very small and are unlikely to have any practical impact.
This analysis adds to evidence supporting the use
of the K10 in epidemiological research
