[An example of psychometric validation of a mental health questionnaire used at a work place]

Most companies utilize original questionnaires developed by the health-care staff to evaluate their workers' mental health status. To build effective strategies, it is crucial to use proper measures validated psychometrically. We demonstrated the process to evaluate the reliability and validity of the original health questionnaire developed by the health-care team of an industrial company. We used the Beck Depression Inventory-II, and the Job Content Questionnaire as the gold standards for external validation. Out of 21 items in the original health questionnaire, 9 items significantly correlated with depression. From the results of a factor analysis, the 9 items composed 2 independent components out of 5 factors. A subscale which consisted of the 9 items from the original questionnaire was proposed as a screening tool to detect depression, but no items of the original questionnaire correlate with the Support subscale nor the Job Control subscales of the JCQ. Just one item correlated with the Job Demand subscale of the JCQ. Additional information should be added to the original questionnaire to evaluate Job Stress based on the Karsek's Job Demand-Control-Support model.