Background: The Hospital Anxiety and Depression scale (HAD) is commonly used to assess emotional distress in different group of patients. Despite emotional distress is common in sudden cardiac arrest survivors (SCA), HAD have not to our best knowledge been psychometrically evaluated in this patient group.

Purpose: The aim was to evaluate the psychometric properties of the HAD, with focus on factor structure, internal consistency and differential item functioning (DIF) for sex and age, in SCA survivors.

Methods: Data from the national Swedish Register of Cardiopulmonary Resuscitation were used, including HAD ratings from in-hospital cardiac arrest survivors, collected 3-12 months after resuscitation. Confirmatory factor analysis (CFA) was used to evaluate the hypothesized two factor structure for Anxiety and Depression, respectively. Ordinal version of Cronbach’s alpha was calculated to evaluate internal consistency reliability of the two factors. Multiple indicator multiple causes CFA models (MIMIC) were used to detect presence of DIF.

Results: The sample consisted of 604 in-hospital cardiac arrest survivors (mean age 69.4±12.6), 384 men and 220 women. The suggested two-factor model was confirmed after item 7 was allowed to cross-load on Depression. The internal consistency was satisfactory for both Anxiety (.92) and Depression (.91). No DIF for sex and age was demonstrated.

Conclusion: This study shows that the HAD Anxiety and Depression subscales are unidimensional. Both scales can also be used to make invariant comparisons between groups of different sex and age. Therefore, HAD can be used to assess psychological distress (anxiety and depression) in SCA survivors.