A psychometric evaluation of the four-item version of the Control Attitudes Scale for patients with cardiac disease and their partners.

BACKGROUND

The four-item Control Attitudes Scale (CAS) was developed to measure control perceived by patients with cardiac disease and their family members, but extensive psychometric evaluation has not been performed.

OBJECTIVE

The aim was to translate, culturally adapt and psychometrically evaluate the CAS in a Swedish sample of implantable cardioverter defibrillator (ICD) recipients, heart failure (HF) patients and their partners.

METHODS

A sample (n=391) of ICD recipients, HF patients and partners were used. Descriptive statistics, item-total and inter-item correlations, exploratory factor analysis, ordinal regression modelling and Cronbach's alpha were used to validate the CAS.

RESULTS

The findings from the factor analyses revealed that the CAS is a multidimensional scale including two factors, Control and Helplessness. The internal consistency was satisfactory for all scales (α=0.74-0.85), except the family version total scale (α=0.62). No differential item functioning was detected which implies that the CAS can be used to make invariant comparisons between groups of different age and sex.

CONCLUSIONS

The psychometric properties, together with the simple and short format of the CAS, make it to a useful tool for measuring perceived control among patients with cardiac diseases and their family members. When using the CAS, subscale scores should be preferred.