Psychometric evaluation of the Hospital Anxiety and Depression Scale 3 months after acute lung injury

Abstract

Purpose: To conduct a psychometric evaluation of the Hospital Anxiety and Depression Scale (HADS) and to evaluate associations of 2 measures of psychological distress with the HADS Anxiety (HADS-A) and HADS Depression (HADS-D) subscales in acute lung injury (ALI) survivors.

Materials and methods: We used 3-month post-ALI follow-up data from 151 participants in a multisite prospective cohort study to evaluate the internal consistency and structure of the HADS subscales and items, respectively. We used Spearman ρ correlations and other statistics to relate the 3-level version of the EuroQol-5D (EQ-5D-3L) anxiety/depression item and Medical Outcomes Study Short Form-36 (SF-36) "mental health"-related domains to the HADS subscales.

Results: Internal consistency was good for each of the HADS subscales (α ≥ .70). Exploratory factor analysis revealed a 2-factor structure (anxiety and depression). The EQ-5D-3L item and the SF-36 mental health-related domain scores were associated with HADS-A (ρ = 0.54 and -0.48 to -0.70, respectively) and HADS-D (ρ = 0.41 and -0.48 to -0.52, respectively) scores (all P < .01). The relationship between the SF-36 mental health domain score and the HADS-A subscale score was particularly strong (ρ = -0.70, P < .01).

Conclusions: When evaluated in ALI survivors, the HADS has good internal consistency and a 2-factor structure. The HADS subscales were substantially correlated with the EQ-5D-3L anxiety/depression item and SF-36 mental health-related domain scores, suggesting convergent validity for these measures of psychological distress in ALI survivors.

Keywords: Acute lung injury; Anxiety; Critical care; Depression; Intensive care unit; Psychometrics.