A contribution to the French validation of the clinical anxiety scale amongst health care workers in Switzerland.

BACKGROUND

Anxiety disorders are frequent but remain often underdiagnosed and undertreated. Hence, valid screening instruments are needed to enhance the diagnostic process. The Clinical Anxiety Scale (CAS) is a 25-item anxiety screening tool derived from the Hamilton Anxiety Scale (HAM-A). However, this scale is not available in French. The General anxiety disorder - 7 (GAD-7) scale, which has been validated in French, is a 7-item instrument with good psychometric properties. This study contributes to the validation of an adapted French version of the CAS, using the GAD-7 as the reference.

METHODS

A forward-backward English-French-English translation of the CAS was performed according to standard practice. The French versions of the CAS and GAD-7 were completed by 127 French speaking healthcare professionals. CAS internal consistency was assessed using Crohnbach's alpha, and test-retest reliability was tested after 15 days in a subsample of 30 subjects. Convergent validity with GAD-7 was assessed using Pearson's correlation coefficient. Test-retest reliability was explored using one-way random effects model to calculate the intra-class correlation coefficient (ICC).

RESULTS

French CAS showed excellent internal consistency (Cronbach's alpha 0.97), high convergent validity with GAD-7 (Pearson's R 0.81, p < 0.001), and very good test-retest reliability (ICC = 0.97, 95% CI 0.93-0.98).

CONCLUSION

The proposed French version of the CAS showed high reliability and validity that need to be further investigated in different populations.