Psychometric characteristics of the Hospital Anxiety and Depression Scale in stroke survivors of working age before and after inpatient rehabilitation.

Abstract

The aim was to examine the psychometric properties of the Hospital Anxiety and Depression Scale (HADS) in cohorts of working age stroke survivors, before and after inpatient rehabilitation. Stroke patients aged 18-66 years registered in the national quality register WebRehab Sweden were included in the study at hospital admission (n = 256), discharge (n = 223), and 1-year follow-up (n = 313). Classical and modern (Rasch) methods were used for psychometric evaluation. The two-factor HADS model measuring anxiety and depression showed better fit than a single factor measuring emotional distress. The instrument's psychometric stability before and after rehabilitation was satisfactory. The anxiety scale showed good psychometric properties, except for item 7, which is not anxiety-specific. Some concerns were observed for the depression items showing weaker discriminant validity, and item 8 performing poorly as a measure of depression. Cronbach's alpha and McDonald's omega coefficients showed satisfactory internal consistency reliability, whereas Rasch person reliability coefficients indicated weaker reliability, especially for the depression scale. Effect size of change between hospital admission and discharge showed a reduction in anxiety and depression symptoms. HADS showed a stable two-factor structure over the rehabilitation period. Patients' perception of items was not affected by the recovery, allowing relevant comparison of HADS scores between different phases of the rehabilitation process. Measures of responsiveness suggest that HADS is sensitive to capturing improvements in emotional distress following rehabilitation interventions. Overall, despite minor psychometric weaknesses, HADS is a suitable instrument for assessing anxiety and depresssion symptoms in stroke patients aged 18-66 years.