Validation of Visual Analogue Scales of job demand and job control at the workplace: a cross-sectional study

Objectives Work-related stress is a major concern. One of the best performing models is the Job Content Questionnaire (JCO) of Karasek, assessing job demand and job control using 18 items. However, the JCO is long and complex. Visual Analogue Scales (VASs) are easy to use and quick to implement. VASs have been validated to assess pain and occupational stress; however, VASs demand and control have not been evaluated. Therefore, we aimed to validate the use of VAS demand and control compared with the 18 items of the JCQ. Design We implemented a cross-sectional observational study, by administering a self-reported questionnaire to the users of Wittyfit software, with a second test (retest) proposed 1 week later. In addition to JCQ, VAS demand and control, we measured sociodemographic outcomes, as well as characteristics of work, sleep, well-being, stress, depression and anxiety. Participants 190 volunteers French workers using WittyFit software participated in the study, and 129 completed the test-retest. Results VAS demand and VAS control correlated with the two Karasek domains from the JCQ, respectively, at 0.59 and 0.57 (p<0.001). Test-retest reliability highlighted concordance coefficients higher than 0.70. Sensitivity was higher than 70% for each VAS. External validity was acceptable. For both demand and control, VAS cut-offs were 75/100. Compared with other workers, senior executives and individuals with master's degrees had higher levels of job control but did not differ in job demand using the VAS and JCQ. Conclusions VAS demand and VAS control are valid, quick, easy to use, and reliable tools for the assessment of job demand and job control. They can be used in daily clinical practice for primary prevention and diagnosis. However, when results are over 75 mm on VAS, we promote the use of JCQ to be more discriminant and specific to initiate action plans to help workers.