Objectives: To evaluate the validity of the checklist individual strength questionnaire (CIS) in the working population. This 20 item self reported questionnaire has often been used in patients with chronic fatigue. To date, no research has focused on the validity of the CIS in occupational groups.
Methods: To evaluate the discriminant validity the CIS was filled out by five groups of employees with expected differences in fatigue. The convergent validity was evaluated by comparing the results of the CIS with the results of three related measures: measured unidimensional fatigue, burnout, and need for recovery.
Results: The CIS was able to discriminate between fatigued and non-fatigued employees in occupational groups. The expected agreement between the results of the CIS and related measures was confirmed.
Conclusions: The CIS seems to be an appropriate instrument for measuring fatigue in the working population.