Evaluation of the Psychometric Properties of the Kessler Psychological Distress Scale (K6) among Quebec Adolescents
Objectives The purpose of this study was to examine the unidimensional structure and psychometric qualities of the short version of the Kessler Psychological Distress Scale (K6) in adolescents living in Quebec. Method Data analyzed were obtained from the 2013-2014 Canadian Community Health Survey and included data from 1618 adolescents. The internal structure of the K6 and invariance by gender and age were tested using confirmatory factor analyses. Convergent and divergent validity of the K6 were also assessed. Finally, Receiver Operating Characteristic (ROC) analyses were performed to determine the predictive power of the K6 in predicting the presence of a major depressive episode. Results The analyses suggest the presence of a unidimensional structure in the Quebec adolescent sample, as well as in the studied subgroups. The invariance of the measure is observed for the age subgroups but cannot be established with certainty for the gender analyses. The results support the convergent and divergent validity of the K6 with adolescents, whereas the alpha and omega values of the K6 indicate that its internal consistency ranges from questionable to acceptable for all respondents and subgroups. The results of the ROC curves reveal that the 4/5 cut-off point best predicts the presence of a major depressive episode among all participants and subgroups. Conclusion Although the K6 has several advantages, the internal consistency and invariance by gender results warrant caution regarding its use to identify the level of psychological distress of Quebec adolescents.