Coronary heart disease (CHD) is a common cause of death and an important cause of morbidity in Ireland. Secondary prevention of heart disease involves long-term management of risk factors among people who have been diagnosed with established CHD. The Scottish Intercollegiate Guidelines Network has defined secondary prevention as the 'identification and modification of risk factors by the introduction of lifestyle measures and pharmacological therapy and cardiac rehabilitation' . Secondary prevention has been recommended as a key strategy for reducing levels of CHD [2, 3]. Secondary prevention can be achieved by stopping smoking, making healthier food choices (including reducing fat intake and increasing intake of fruit, vegetables and fibre), becoming physically active, achieving an ideal weight, consuming alcohol in moderation, appropriate prescription of, and adherence to, pharmacological therapy, achieving blood pressure level at or under 140/90 mmHg and achieving a total cholesterol level at or below 5 mmol/l .
Most people with CHD regularly attend their general practitioner and general practice has been highlighted as an ideal setting for secondary prevention initiatives . Previous studies of provision of secondary prevention in general practice have identified sub-optimal levels [4–6]. Current indications suggest that there is considerable room for improvement in the provision of secondary prevention for patients with established heart disease on the island of Ireland . Recent data from the national Heartwatch programme suggest that 44% of Irish patients with established heart disease have a systolic blood pressure above the recommended guidelines of 140 mmHg, and that 36% have a baseline cholesterol level of greater than 5 mmol/l (Leahy J, personal communication). In a survey of secondary preventive care of 1,600 patients, from 35 randomly selected general practices in the west of Ireland, results were as follows: 23% of patients were regular smokers, 45% had cholesterol readings greater than 5 mmol/l and 34% had blood pressure readings greater than 140/90 mmHg. In addition, GP records were found to be incomplete, with 38% of patients with no record of smoking status and 25% with no cholesterol reading. Information from Northern Ireland suggests a similar situation: a recent survey found that among patients with a confirmed diagnosis of CHD 18% smoked, 25% had a body mass index (BMI) greater than 30, 51% had a systolic blood pressure greater than 140 mmHg and approximately 50% had cholesterol levels greater than 5 mmol/l .
Randomised controlled trials have investigated the effectiveness of secondary prevention interventions including health visitor advice , nurse-led secondary prevention clinics [10, 11], outreach visits to practices by nurses trained in cardiovascular risk factor recording , provision of specialist liaison nurses to bridge the gap between secondary and primary care , postal prompts to patients to encourage lifestyle changes , audit and systematic recall of patients from disease registers , combined training to all practice staff in information systems and evidence-based medicine  and a cognitive-behavioural disease management programme .
These trials have reported a number of successful outcomes, including increased physical activity [9, 10, 17], improved diet [9, 10, 17], increased health functioning [9, 10, 17], increased patient assessment and recording of risk factors [12, 14–16], increased rate of consultation for coronary heart disease , improvements in medication prescribing [10, 15], improved lipid management [10, 14, 16], reduction in cholesterol level , improved blood pressure management , increased lifestyle advice provision  and reduced anxiety and depression .
However, with the exception of the PIER trial  which achieved significant reductions in cholesterol levels among intervention group patients, trials have not achieved significant improvements in objective biophysical risk factors, such as blood pressure or cholesterol levels.
A systematic review identified twelve randomised trials of disease management programmes for patients with established heart disease . It concluded that such programmes do improve processes of care, reduce hospital admissions and enhance quality of life and functional status in patients with CHD. However, the reviewers noted that studies included imprecise descriptions of both the interventions and the usual care provided to the control groups, resulting in an inability to determine the incremental benefits of the various components of each intervention. Reviewers concluded that several important issues require further clarification, including the optimal mix of interventions and the cost-effectiveness or the economic impact of such interventions. Another earlier systematic review  also noted both the lack of detail provided of complex health service interventions, especially in the description of the usual care provided to control groups, and the need for the careful design and evaluation of different implementation models of secondary prevention.
Further possible explanations for the lower than expected clinical impact of secondary prevention interventions to date include inadequate consideration of doctors' and patients' perspectives on heart disease, lack of patient-centredness of the intervention and a failure to tailor practice interventions to individual patients and practices . Wiles , utilising a qualitative approach as part of the SHIP study, especially emphasised the failure of 'official accounts' to acknowledge patient perceptions as a key feature in people's reluctance to adopt lifestyle change.
There is substantial evidence that structured systematic care is important to improve levels of secondary prevention of coronary heart disease, and an effective register, recall system and routine audit of care are essential components of such a system [13, 21]. There is also some evidence to suggest that nurse-led clinics , cognitive behavioural interventions [17, 22, 23] and tailored training identified by practice staff  are effective in improving secondary prevention in general practice and facilitating patients to make lifestyle changes.
A recent Cochrane review  of interventions to implement prevention in primary care highlighted the need to tailor interventions to address specific barriers to change in a particular setting. The review also concluded that multi-faceted interventions may be more effective than single interventions, as more barriers to change can be addressed. The authors of the review recommend that future research should analyse barriers to change and report interventions to implement preventive services in more detail, to clarify how interventions relate to specific barriers. Since such complex interventions are likely to be more costly than single interventions, these reviewers also advise that economic evaluations should be included in future studies.
The SPHERE Study aims to take these recommendations on board in developing an intervention to improve secondary prevention of CHD in general practice in Ireland. The SPHERE study involves the implementation of a structured systematic programme of care for patients with CHD attending general practice. The SPHERE intervention is multi-faceted and has been developed to respond to the barriers and solutions to optimal secondary prevention identified in preliminary qualitative research with practitioners and patients. The delivery of the intervention is tailored as much as possible to the needs of practices and patients. The process of the intervention will be documented and described in sufficient detail to allow replication of the intervention and to enable identification of effective intervention components. The intervention will be implemented over a 24 month period, with data collection at baseline, 12 months and 24 months. Data collection at these time points will enable identification of any initial and/or sustained changes effected by the intervention. An economic evaluation of the intervention will be carried out. The implementation of the intervention will be monitored throughout the duration of the trial and documented.
In summary, SPHERE will add to what is already known in respect of secondary prevention in primary care, i.e.
that structured programmes, with continued support and follow-up of patients, help improve recording of process measures of preventive care, patients' functional status, quality of life and lifestyle change [9–11, 15, 17, 25].
prompts to patients improve their attendance but there is no associated change in measures of risk [13, 15].
structured recall programmes which do not take account of individual practice needs improve recording but not prescribing ; provision of training, tailored to practice needs of access to evidence of effectiveness of secondary prevention is associated with improved prescribing 
patient centred consultations impact positively on health outcomes  but must be accompanied by attention to disease management guidelines to achieve clinical objectives .
record organisational detail of care, in both intervention and control practices
provide information and training tailored to practices' needs for delivery of secondary prevention
support patient centred consultations and practitioners' adherence to disease management guidelines.