Measurement of psychological distress in the NSW Population Health Survey

The NSW Population Health Survey uses Kessler 10 Plus (K10) (Kessler et al, 2002) to measure psychological distress in people aged 16 years and over. K10 is a 10-item questionnaire that measures anxiety, depression, agitation, and psychological fatigue in the most recent 4-week period. For each item in the questionnaire there is a 5-level response scale based on the amount of time (from none of the time to all of the time) the person experienced the particular symptom. When scoring responses, 1-5 points were assigned to each symptom, with 1 indicating none of the time and 5 indicating all of the time. The total score ranges from 10 points (all responses none of the time) to 50 points (all responses all of the time). Responses are classified into four categories: low when the score is 10-15, moderate when the score is 16-21, high when the score is 22-29, and very high when the score is 30 or higher.

The indicator showing high and very high distress includes persons with responses scored as a Kessler 10 (K10) score of 22 or above.

The questions as used on the NSW Population Health Survey to define the indicator are:

In the past 4 weeks, about how often did you feel tired out for no good reason?

In the past 4 weeks, about how often did you feel nervous?

In the past 4 weeks, about how often did you feel so nervous that nothing could calm you down?

In the past 4 weeks, about how often did you fell hopeless?

In the past 4 weeks, about how often did you feel restless or fidgety?

In the past 4 weeks, about how often did you feel so restless you could not sit still?

In the past 4 weeks, about how often did you feel depressed?

In the past 4 weeks, about how often did you feel that everything was an effort?

In the past 4 weeks, about how often did you feel so sad that nothing could cheer you up?

In the past 4 weeks, about how often did you feel worthless?

Details about the NSW Population Health Survey and the questions asked are available in here.

Note the original K10 questions use a reference period of 30 days not 4 weeks (see here).

References:
Kessler, R.C., Barker, P.R., Colpe, L.J., Epstein, J.F., Gfroerer, J.C., Hiripi, E., Howes, M.J, Normand, S-L.T., Manderscheid, R.W., Walters, E.E., Zaslavsky, A.M. (2003). Screening for serious mental illness in the general population. Archives of General Psychiatry, 60(2), 184-189.
Copyright © Ronald C. Kessler, PhD. All rights reserved.