Psychometric assessment of the Cardiac Depression Scale Short Form in cardiac outpatients

Depression is common in patients with cardiovascular disease and is a risk marker for increased mortality. The valid and reliable detection of depression is fundamental to the appropriate management of these patients.

The aim of this study was to evaluate the psychometric characteristics of the Cardiac Depression Scale Short Form 1 (DS-SF1) and the Cardiac Depression Scale Short Form 2 (DS-SF2) for screening cardiac outpatients in clinical settings.

Adult cardiac outpatients attending a cardiovascular clinic completed the Cardiac Depression Scale (CDS), two versions of the DS-SF (DS-SF1 and DS-SF2) and the Physical Health Questionnaire 2 (PHQ2-Y/N) prior to their cardiac consultation.

Data from 326 patients (224 men; mean±SD age 66.25±14.39 years) were analysed. The DS-SF1 (mean score 16.28±5.70) had good construct validity with the CDS (r=0.77; p<0.0001), adequate convergence with the PHQ2-Y/N (r=0.59; p<0.0001) and good internal consistency (α=0.73). The DS-SF2 (mean score 15.80±6.80) had a better construct validity with the CDS (r=0.84; p<0.0001) and the PHQ2-Y/N (r=0.69; p<0.0001) and better internal consistency (α=0.82). The DS-SF2 showed strong criterion validity with the CDS with a DS-SF2 ⩾15 cut-point yielding 90% sensitivity and 73% specificity (area under the curve 0.92) for detecting depression (CDS ⩾95).

These findings confirm the excellent psychometric properties of the DS-SF2 as an ideal tool for screening depression in cardiac patients in clinical practice. The DS-SF2 should be regarded as the definitive version of the DS-SF.