Psychometric properties of the Hospital Anxiety and Depression Scale (HADS) in individuals with stable chronic obstructive pulmonary disease (COPD): a systematic review

PURPOSE: The Hospital Anxiety and Depression Scale (HADS) is used to assess anxiety and depression in individuals with chronic obstructive pulmonary disease (COPD); however, its measurement properties lack critical appraisal. We aimed to summarize and critically appraise the validity, reliability, and responsiveness of the HADS in COPD. MATERIALS AND METHODS: Five electronic databases were searched. The Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines were used to assess the methodological and evidence quality in the selected studies. RESULTS: Twelve studies assessed the psychometric properties of the HADS-Total and its subscales HADS-Anxiety and HADS-Depression in COPD. High-quality evidence supported the structural and criterion validity of the HADS-A, the internal consistency of the HADS-T, HADS-A, and HADS-D with Cronbach's alpha values of 0.73-0.87, and before-after treatment responsiveness of HADS-T and its subscales (minimal clinically important difference = 1.4-2; effect size = 0.45-1.40). Moderate-quality evidence supported the test-retest reliability of the HADS-A and HADS-D with excellent coefficient values of 0.86-0.90. CONCLUSIONS: The HADS-A is recommended for use in individuals with stable COPD. The lack of high-quality evidence on the validity of the HADS-D and HADS-T prevented drawing robust conclusions about their clinical utility in COPD.