The temporal stability of the Kessler Psychological Distress Scale

Objective: The ten-item Kessler Psychological Distress Scale (K10) was designed as a screening tool to identify mental illness in epidemiological surveys. In recent years, it has also been employed in treatment studies and clinical settings to measure changes in psychological distress. However, no study to date has validated this extended use of the K10 by examining its temporal stability. This was the aim of the current study. Method: The K10 was administered on two occasions to a treatment-seeking sample (n = 289) and a non-treatment seeking sample (n = 129). To investigate the K10's temporal stability over a range of clinically relevant time periods, test-retest reliability estimates were computed for multiple time intervals from 1-2 weeks to 8-13 weeks in the treatment-seeking sample. Results: For the testing interval of 1-2 weeks, the K10 demonstrated sound test-retest reliability in the treatment-seeking sample (ICC = .89; r = .80) and in the non-treatment-seeking sample (ICC = .86; r = .76). Comparable estimates were observed for the longer testing intervals in the treatment-seeking sample (ICCs = .84-.90; rs = .72-.81). Conclusion: This study provides evidence demonstrating the temporal stability of the K10, and supports its continued implementation as an outcome measure in mental health research and treatment.

Automated summary

This study aimed to validate the temporal stability of the K10 over various time periods, and found that it demonstrated sound test-retest reliability in both treatment-seeking and non-treatment-seeking samples. The results support the continued implementation of the K10 as an outcome measure in mental health research and treatment.