Given the prevalence of cardiovascular disease and the high rates of depression among cardiac patients, there is a need to develop practical ways to identify this population and provide pragmatic general-practitioner–based interventions for managing depression as a comorbid condition.

The Identifying Depression As a Comorbid Condition (IDACC) study employed a hybrid design, incorporating a randomized controlled trial nested within a prospective cohort study. IDACC screened for depression in patients hospitalized in South Australia for a range of cardiac conditions, with outcome measures monitored for 12 months after discharge. The subgroup identified as depressed was entered into the nested IDACC trial, which tests the hypothesis that identifying depression and offering an evidence-based intervention to general practitioners, incorporating multidisciplinary telephone case conferencing, will reduce levels of depression, improve quality of life, and reduce associated economic costs.

At baseline, 46.3% of 1455 participants screened were classified as depression cases on the basis of their score on the Center for Epidemiological Studies Depression Scale (≥16) or the Hospital Anxiety and Depression Scale (≥8). Elevated scores were associated with being younger, female, divorced or separated, not employed, living alone, having a lower level of education, and having poorer health and quality of life. Nearly one fifth (19.4%) of participants had Center for Epidemiological Studies Depression Scale scores >27, which is indicative of major depression.

This project confirms, in an Australian setting, the high prevalence of depressive symptoms among hospitalized cardiac patients. Follow-up over 12 months will enhance understanding of the natural history of depression in cardiac patients, while the nested trial will inform on effectiveness of an intervention involving tailored advice and support to general practitioners.