Nübling et al. BMC Public Health 2010, 10:428 http://www.biomedcentral.com/1471-2458/10/428 scales, practicability, etc.). Assessment of the reliability, generalisability, construct validity, and criterion validity of the single scales of the COPSOQ showed good mea- suring qualities for the majority of the scales. Detailed information on the assessment of psychometric proper- ties (in terms of the ISO 10075-3 [18]) and on the con- tent of the questionnaire is given by Nübling et al. [19,20]. Further information is also available on the Ger- man COPSOQ website: http://www.copsoq.de (mostly in German). The final instrument includes 19 aspects (18 scales and 1 single item) assessing the psychosocial work environment grouped into the sections: demands (4 scales), influence and development (5 scales), interperso- nal support and relationship (8 scales and 1 single item), and job insecurity (1 scale) and six constructs (4 scales and 2 single items) assessing the employee’s reaction to the workplace situation as outcome factors: job satisfac- tion, intention to leave, general health, burnout (scale: personal burnout), cognitive stress and satisfaction with life. In total 87 Likert-scaled items with mostly 5 answer categories are included. Figure 1 shows the content of the German standard COPSOQ questionnaire and the direction of the presumed relationship between work- place factors and individual’s reactions. Since 2005 the German COPSOQ standard version has been used for the formation of a comprehensive database with profession specific reference values for psychosocial factors at work. The data of all Page 3 of 12 organizations performing a COPSOQ assessment in cooperation with the FFAS (Freiburger Forschungsstelle Arbeits- und Sozialmedizin; Freiburg Research Centre for Occupational and Social Medicine) were included in the COPSOQ database. The German COPSOQ database is a dynamically growing data pool which facilitates the interpretation of the results of single organisations/enterprises using comparisons of the results with profession specific refer- ence values. Professions/occupations in the database are classified according to the system of job classifications KdB92 ("Klassifikation der Berufe 1992”) of the German Federal Statistical Office http://www.destatis.de. In this study some specific questions concerning the working schedule and specific aspects in the care of the elderly (e.g. working with depressed patients) were added to the standard version. All COPSOQ single items and all scales consisting of several items have a theoretical range from 0 (which is the lowest possible amount of the aspect under investi- gation) to 100 (corresponding to the highest possible value). Scale values presented are thus mean values and not percentages or prevalence rates, which has the advantage that no information is lost by collapsing cate- gories in order to calculate percentages. Whether a high value is to be judged as positive or as negative depends on the content: a high value for “influence at work” is positive while a high value for “burnout” is negative. Demands - Quantitative demands - Emotional demands - Demands for hiding emotions - Work - privacy conflict Influence and development - Influence at work - Degree of freedom at work - Possibilities of development - Meaning of work - Workplace commitment Further parameters - Job insecurity Supplementary scales - conflicts with clients - shift work - teacher items -… Figure 1 Content of the German standard COPSOQ. Interpersonal relations and leadership - Predictability - Role clarity - Role conflicts - Quality of leadership - Social support - Feedback - Social relations - Sense of community - Mobbing Strain (effects, outcomes) - Job satisfaction - Intention to leave - General health - Burnout - Cognitive stress - Satisfaction with life