A new look at the construct validity of the K6 using Rasch analysis

Khan, Asaduzzaman, Chien, Chi-Wen and Burton, Nicola W. (2014) A new look at the construct validity of the K6 using Rasch analysis. International Journal of Methods in Psychiatric Research, 23 1: 1-8. doi:10.1002/mpr.1431

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Author Khan, Asaduzzaman
Chien, Chi-Wen
Burton, Nicola W.
Title A new look at the construct validity of the K6 using Rasch analysis
Journal name International Journal of Methods in Psychiatric Research   Check publisher's open access policy
ISSN 1557-0657
Publication date 2014-01-16
Sub-type Article (original research)
DOI 10.1002/mpr.1431
Volume 23
Issue 1
Start page 1
End page 8
Total pages 8
Place of publication Chichester, West Sussex, United Kingdom
Publisher John Wiley & Sons
Language eng
Formatted abstract
The Kessler six-item psychological distress (K6) scale is widely used to screen for mental disorders; however, information is lacking on the rating scale performance or dimensionality structure of the scale. This study used a population based sample (n = 7596) to evaluate the construct validity of the K6 scale using Rasch partial credit analysis. The analysis showed that almost all of the five-point rating scales in the K6 items were used appropriately to differentiate psychological distress of the study participants. The analysis provided evidence of unidimensionality of the scale, although items 1 (so sad) and 3 (restless or fidgety) might offer a potential second off-dimensional component. All items appeared to fit the Rasch model's expectation as demonstrated by the acceptable item fit statistics. The study participants demonstrated valid response patterns when answering K6 items, except for some who were younger or had higher psychological distress. This study using Rasch analysis confirms the construct validity of the K6 scale and suggests that the K6 is a useful and valid instrument for assessing psychological distress in the mid-aged general population. Further research can facilitate better understanding about the unidimensionality of the scale.
Keyword Kessler
Psychological distress
Construct validity
Rasch analysis
Mental health
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Authors prepress title "A new look at the construct validity of the Kessler K6 using Rasch analysis". Article first published online: 16 JAN 2014

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
School of Health and Rehabilitation Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 4 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 05 Feb 2014, 02:23:02 EST by Asad Khan on behalf of School of Health & Rehabilitation Sciences