The World Bank and World Health Organisation have predicted that by 2020, coronary heart disease (CHD) and depression will be the two top causes of global health burden and disability. As well as causing personal suffering, depression is a major public health problem responsible for 100 million lost working days in England and Wales at a cost of £9 billion per annum .
In the United Kingdom (UK), depression is one of the commonest reasons for consulting a general practitioner (GP). Up to 17% of consecutive GP attendees suffer from depression . In the UK, 95% of people suffering from depression are treated solely in primary care .
Depression has been found to be more common in patients with coronary heart disease (CHD) with a prevalence of 20% . Depression also increases the incidence and recurrence of acute coronary syndromes and death in patients with heart disease . This increase in cardiac risk is independent of other risk factors for CHD . The reason for the increased morbidity and mortality is unclear but may be due to increased activity of the immune/inflammatory pathways in depression, activating atherogenesis and plaque formation .
Depression is associated with a 50% increase in the costs of long term medical care after controlling for the severity of the physical illness. Some of these costs are related to the association between depression and adverse health risk behaviours such as smoking, diet, lack of exercise and a lack of adherence to self-care regimes. Depression as cause or consequence of physical illnesses such as CHD may exacerbate the perceived severity of symptoms and with an increase in health service utilisation. Treating depression and improving outcomes for depression has been shown to reduce health costs in people with physical illness[7, 8]. It therefore seems important to address the care of patients with coronary heart disease and co-morbid depression in the primary care setting.
In the UK, GPs are now remunerated for depression case-finding in patients with CHD . This is because evidence from two large trials in the United States has provided an indication in post hoc sub-group analyses that there may be cardiovascular benefits from treating depression using antidepressant medication[10, 11]. Mortality seems to have been reduced in those whose depression improved and in those who took sertraline [12, 13]. However, the natural history, morbidity and mortality of depression in the primary care population of patients with CHD are not known. It is also unclear how primary care professionals should manage additional cases of depression that may be identified in their CHD patients. Observational cohort studies are needed to help determine the effect of policy implementation on the patient's cardiac and depression outcomes as well as the effects of co-morbidity on morbidity and mortality. If the incidence of depression in patients with CHD is not solely a function of the current physical status, a cohort study will enable other factors associated with the incidence of depression e.g. factors relating to quality of life, illness attribution and social support, to be determined.
There are a number of treatment options for managing depression in primary care e.g. antidepressant medication, supervised exercise, guided self help, problem solving, computerised cognitive behavioural therapy (cCBT), group or individual CBT or interpersonal therapy (IPT) . However the treatment preferences of patients with CHD are unknown. Primary care professional treatment preferences for managing depression in this population are also unknown. As with most physical illness in primary care settings, it is also unclear where the boundary exists between distress secondary to the physical condition and depression that would benefit from treatment. Qualitative studies with patients and their primary care professionals are needed to explore this further. A recent working party on the management of depression in CHD concluded that randomised controlled trials of stepped depression care versus treatment as usual for patients with CHD and depression are needed . This programme of research will inform a randomised controlled trial of the effectiveness and cost-effectiveness of a case management approach to manage primary care patients with coronary heart disease and co-morbid depression. Case management has been shown to improve outcomes for depression in primary health-care settings , but there has been no research to determine whether it is effective in patients with symptomatic coronary heart disease. Case management has been defined as 'taking responsibility for following-up patients; determining whether patients were continuing the prescribed treatment as intended; assessing whether depressive symptoms were improving; taking action when patients were not adhering to guideline based treatment or were not showing expected improvement'. It consists of five essential components :
identification of patients in need of services
Assessing individual patient's needs
Developing a treatment plan
Monitoring outcomes and altering care when favourable outcomes are not achieved
A randomised controlled trial is necessary to determine whether case management for this population is more effective than treatment as usual both in terms of depression and cardiac outcomes. A pilot randomised controlled trial is needed first to inform the design of the definitive randomised control trial.
This protocol describes a programme of research to develop and test a stepped care intervention for depression and coronary heart disease in primary care. It consists of 4 inter-related studies.
A 4 year cohort study of patients with coronary heart disease
A qualitative study of patients with coronary heart disease and co-morbid depression treatment preferences
A qualitative study of general practitioners (GPs) and practice nurses (PNs) treatment preferences for this patient group
A pilot randomised controlled trial of a case management programme for depressed primary care patients with CHD.
The first three studies will inform the development of the pilot randomised controlled trial (study 4). As the four studies are closely related and the randomised controlled trial depends on the conduct and findings of the other studies, the study protocols will be described in turn.