Table 1.
Variables of the study instrument used in the analyses
| Variables | Name and source of the original scales and items | α | Items (n) |
|---|---|---|---|
| Socio-demographic factorsa | 18 | ||
| Health behaviour | |||
| Physical activity | Health Questionnaire age 18–64 years [29] | – | 1 |
| Dietary habits | Food Frequency Questionnaire [30] | – | 15 |
| Smoking | Health Questionnaire age 18–64 years [7] | – | 2 |
| Alcohol consumption | AUDIT-C [31, 32] | – | 3 |
| Health status | |||
| General health status | Survey in vocational schools in Bielefeld [36] | – | 1 |
| Diseases and complaints | Work Ability Index – Questionnaire [33] | – | 6 |
| Self-efficacy | Self-efficacy scale [24] | 0.85 | 10 |
| Irritation | Irritation scale [22] | 0.88 | 8 |
| Occupational situation and prospects | |||
| Job satisfaction | COPSOQ: German standard version [23, 34] | 0.81 | 7 |
| Job strain and prospects | Additional questions (e.g., taking into account the current work situation, do you want to stay in this profession for the next five years?) | – | 3 |
aIncluded age, sex, height, weight, migration background, socioeconomic status and year of education
α = Cronbach’s alpha, AUDIT-C Alcohol Use Disorder Identification Test, COPSOQ Copenhagen Psychosocial Questionnaire