The factor structure of the cardiac anxiety questionnaire, and validation in a post-MI population

CVD-patients with higher levels of cardiac anxiety suffer psychologically, as well as being at increased risk for cardiac morbidity and mortality. Therefore it is important to be able to assess CA in a clinical setting. It is currently measured with the Cardiac Anxiety Questionnaire, which has conflicting findings regarding its factor structure, and it has not been validated in a Swedish population. This study aimed to examine the factor structure of CAQ and its psychometric properties in a Swedish CVD-population.

Nine hundred thirty patients post-MI were recruited at different Swedish hospitals and completed the CAQ, along with several other questionnaires. Exploratory factor analysis and confirmatory factor analysis were conducted to explore factor structure and to inspect various factor solutions from previous research. Standard psychometric tests were performed for the CAQ to test its validity and reliability.

The exploratory analysis found a model with the factors Fear/Worry, Avoidance and Attention. The confirmatory factor analysis indicated that a 3-factor solution best fitted the data, but with certain items removed. Additionally, psychometric properties turned out acceptable in a Swedish post-MI population.

We conclude that the original 3-factor structure of the CAQ is valid, but that the questionnaire could be revised in regard to some items. A shorter 10-items version could also be considered. We also confirm that the CAQ is a valid instrument to measure CA in a Swedish MI-population.

The study was registered on ClinicalTrials.gov on 05/01/2012 (NCT01504191).