Validity and Usefulness of the Hospital Anxiety and Depression Scale in Carers of People with Dementia: Evidence from Confirmatory Factor Analysis, Concurrent Validity, and Measurement Invariance in a Large Sample

In this group the HADS measured three factors; depression, anxiety, and negative affectivity. The depression scale can be used as originally intended, supporting results of large clinical trials. The HADS does not validly measure distress or anxiety. Consequently, clinical practice recommendations could be revisited, and future research trials should not use HADS anxiety or distress as outcomes. Researchers should pay attention to measurement invariance when using HADS to compare carer subgroups.