The Swedish Demand-Control-Support Questionnaire (DCSQ): factor structure, item analyses, and internal consistency in a large population.

AIM: This paper examined the psychometric properties of the Swedish Demand-Control-Support Questionnaire (DCSQ), which is a shorter and modified version of Karasek's Job Content Questionnaire (JCQ).

METHODS: The study encompassed 5,227 workers born in 1953-57 from the population-based Hordaland Health Study. DCSQ, a 17-item questionnaire, covers psychological demands, decision latitude, and social support in the workplace. The workers were manually classified according to the Standard Classification of Occupations. The main statistical methods were principal component analyses, and estimation of internal consistency and the subscales' shared variance by Cronbach's coefficient a and Pearson's correlation coefficients, respectively.

RESULTS: The study gave support to the tri-dimensional factor structure of DCSQ. Decision latitude tended to split into skill discretion and decision authority in skill-level homogeneous samples. The specificity of the item loadings was satisfactory except for "conflicting demands". The inter-correlation of the three main subscales was weak. The internal consistency of the subscales was generally satisfactory.

CONCLUSIONS: The psychometric properties of DCSQ are satisfactory. Being shorter and easier to use than the more comprehensive JCQ, DCSQ represents an important alternative, particularly if respondent burden and data-collection costs need to be minimized.