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The online version of this article (doi:10.1186/1477-7525-10-141) contains supplementary material, which is available to authorized users.
The authors declare that they have no competing interests.
CFS participated in the study design and drafted the manuscript. DRT conceived and coordinated the study, participated in its design and helped to draft the manuscript. AGS participated in the study design and collected the data. DLH participated in the design of the study and helped to draft the manuscript. RW conducted the Mokken scaling analysis and helped to draft the manuscript. All authors read and approved the final manuscript.
There is a high prevalence of depression in patients with heart failure (HF) that is associated with worsening prognosis. The value of using a reliable and valid instrument to measure depression in this population is therefore essential. We validated the Cardiac Depression Scale (CDS) in heart failure patients using a model of ordinal unidimensional measurement known as Mokken scaling.
We administered in face-to-face interviews the CDS to 603 patients with HF. Data were analysed using Mokken scale analysis. Items of the CDS formed a statistically significant unidimensional Mokken scale of low strength (H<0.40) and high reliability (Rho>0.8).
The CDS has a hierarchy of items which can be interpreted in terms of the increasingly serious effects of depression occurring as a result of HF. Identifying an appropriate instrument to measure depression in patients with HF allows for early identification and better medical management.