Measuring psychological stress and strain at work - Evaluation of the COPSOQ Questionnaire in Germany

The undisputed increase of the relevance of mental work load is confronted with a lack of qualified or at least well documented measuring instruments covering all important aspects. The COPSOQ (Copenhagen Psychosocial Questionnaire), a comprehensive instrument for the assessment of psychosocial factors at work, was tested in a partly modified version in a large German sample (N = 2561 employees). The aims of the study were the detailed investigation of the psychometric measurement properties, and based on these results, the development of an abbreviated version of the instrument. The analysis of objectivity, acceptance, practicability, sensitivity and content validity of the questionnaire as a whole did not show any problematic results – with some limitations regarding the length of the questionnaire. The assessment of the reliability, generalisability, construct validity, criterion validity and diagnostic power of the single scales showed medium to good measuring qualities for the majority of the scales (i.e. Cronbach’s alpha mostly >0.7). In addition, the psychometric properties were very similar to those in the Danish COPSOQ-study. Considering all aspects of the measurement quality, a shortened version of the instrument was created. It attempts to combine measuring qualities as high as possible with a number of questions as low as possible. The German COPSOQ questionnaire is a free screening-instrument for the recording of psychosocial work load and strain for all enterprises and organisations interested. The next step is the construction of a "job exposure matrix" for psychosocial factors at work, that means a central database with work load profiles and reference values for as many occupational groups as possible.