Open Access Research article

Comparison of alternative versions of the job demand-control scales in 17 European cohort studies: the IPD-Work consortium

Eleonor I Fransson12*, Solja T Nyberg3, Katriina Heikkilä3, Lars Alfredsson1, De Dirk Bacquer4, G David Batty56, Sébastien Bonenfant7, Annalisa Casini8, Els Clays4, Marcel Goldberg79, France Kittel8, Markku Koskenvuo10, Anders Knutsson11, Constanze Leineweber12, Linda L Magnusson Hanson12, Maria Nordin13, Archana Singh-Manoux59, Sakari Suominen1415, Jussi Vahtera1416, Peter Westerholm17, Hugo Westerlund125, Marie Zins79, Töres Theorell12 and Mika Kivimäki1835

Author Affiliations

1 Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden

2 School of Health Sciences, Jönköping University, Jönköping, Sweden

3 Finnish Institute of Occupational Health, Helsinki, Finland

4 Department of Public Health, Ghent University, Ghent, Belgium

5 Department of Epidemiology and Public Health, University College London, London, UK

6 MRC Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK

7 Versailles-Saint Quentin University, Versailles, France

8 School of Public Health, Université Libre de Bruxelles, Brussels, Belgium

9 Inserm U1018, Centre for Research in Epidemiology and Population Health, Villejuif, France

10 Department of Public Health, University of Helsinki, Helsinki, Finland

11 Department of Health Sciences, Mid Sweden University, Sundsvall, Sweden

12 Stress Research Institute, Stockholm University, Stockholm, Sweden

13 Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden

14 Department of Public Health, University of Turku, Turku, Finland

15 Folkhälsan Research Center, Helsinki, Finland

16 Finnish Institute of Occupational Health, Turku, Finland

17 Occupational and Environmental Medicine, Uppsala University, Uppsala, Sweden

18 Department of Behavioral Sciences, University of Helsinki, Helsinki, Finland

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BMC Public Health 2012, 12:62  doi:10.1186/1471-2458-12-62

Published: 20 January 2012

Abstract

Background

Job strain (i.e., high job demands combined with low job control) is a frequently used indicator of harmful work stress, but studies have often used partial versions of the complete multi-item job demands and control scales. Understanding whether the different instruments assess the same underlying concepts has crucial implications for the interpretation of findings across studies, harmonisation of multi-cohort data for pooled analyses, and design of future studies. As part of the 'IPD-Work' (Individual-participant-data meta-analysis in working populations) consortium, we compared different versions of the demands and control scales available in 17 European cohort studies.

Methods

Six of the 17 studies had information on the complete scales and 11 on partial scales. Here, we analyse individual level data from 70 751 participants of the studies which had complete scales (5 demand items, 6 job control items).

Results

We found high Pearson correlation coefficients between complete scales of job demands and control relative to scales with at least three items (r > 0.90) and for partial scales with two items only (r = 0.76-0.88). In comparison with scores from the complete scales, the agreement between job strain definitions was very good when only one item was missing in either the demands or the control scale (kappa > 0.80); good for job strain assessed with three demand items and all six control items (kappa > 0.68) and moderate to good when items were missing from both scales (kappa = 0.54-0.76). The sensitivity was > 0.80 when only one item was missing from either scale, decreasing when several items were missing in one or both job strain subscales.

Conclusions

Partial job demand and job control scales with at least half of the items of the complete scales, and job strain indices based on one complete and one partial scale, seemed to assess the same underlying concepts as the complete survey instruments.

Keywords:
Job demands; Job control; Job strain; Work stress; Agreement