Research projects

TrueBlue: A collaborative model of care for the management of type 2 diabetes mellitus (T2DM), coronary heart disease (CHD) and co-morbid depression

Principal researchers

Professor James Dunbar
Professor Prasuna Reddy
Dr Michael Coates
Dr Mark Morgan


Greater Green Triangle University Department of Rural Health
Flinders and Deakin Universities



Award type

Beyond Blue grant

Project completion year


Project brief

Depression, diabetes and heart disease represent three of the leading disease burdens, with all three conditions identified as National Health Priority Areas. Coronary heart disease and diabetes frequently co-exist and the impact of depression on both has been shown to significantly worsen the conditions.

In patients with either type 2 diabetes mellitus (T2DM) or coronary heart disease (CHD) the presence of depression leads to increased morbidity and mortality. However, this co-morbid depression is often missed in routine general practice and it remains under-diagnosed and under treated, especially when in the presence of T2DM or CHD.

With these chronic conditions typically managed through general practice, the Greater Green Triangle project developed, tested and implemented a ‘best practice’ model for the management of diabetes, heart disease and co-existing depression which has been implemented across 20 general practices in urban and rural areas of New South Wales, South Australia and Victoria.

To cope with increasing chronic disease, particularly if co-morbid depression is to be effectively managed, new models of service delivery will be required. This is especially the case in rural and regional areas where the shortage of health professionals means that general practitioners (GPs) have less access to specialist and allied health services for their patients.

This study demonstrates that the practice nurse (PN) can work with the GP to undertake some of the protocol-driven aspects of chronic disease care and assist in the detection and management of co-morbid depression. In this ’collaborative care’ model, the PN takes the role of case manager to ensure coordination of services and timetabled recall of patients.

The True Blue study was a cluster randomised trial that compared usual care to an intervention involving practice nurses who provided guideline based, patient-centred management of depression and chronic disease, either type 2 diabetes [T2DM] or coronary heart disease [CHD] or both. Eighteen urban and rural Australian general practice clinics were recruited and patients on their CHD and T2DM registers were surveyed.

Key findings

Prevalence of depression of patients on chronic disease registers

Overall, 1471 responses were received to the surveys distributed to 5,219 patients on the T2DM and CHD registers of participating clinics, a return rate of 28 per cent. Of these responses, a total of 584 (40 per cent) were patients who had a depression score of five or more on the PHQ-9 questionnaire. 

Taking into account self selection bias, the survey results (40 per cent) were similar to the data from the Fremantle Diabetes Study [Bruce et al 2005], which estimated that 31.5 per cent of a sample of 1,273 people with type 2 diabetes were reported as having depression.

Homogeneity of patients in the control and intervention arms of study

There was no difference at the 95 per cent confidence level between Intervention and Control groups on mean PHQ9 score at beginning of trial for both mildly (PHQ≥5 to <10) and clinically depressed (PHQ-9 score of ≥10) patients.

Treatment impact between control and intervention arms of study at six months

Results show significantly greater improvement in depression scores at six months for the intervention group compared with the control group for clinically depressed patients (PHQ-9 score of ≥10). There was no statistical difference in the outcomes of mildly depressed patients in the intervention and control groups.

Practical outcomes

One of the key practical issues for primary care clinicians is the identification of depression in their patients.  Meadows et al (2001) suggest that while the 1997 Australian National Survey of Mental Health and Wellbeing indicates that 84 per cent of people with a mental disorder consulted a GP in the year prior to survey, only 29 per cent consulted in relation to a mental health problem. This gap may be explained by the existence of significant community stigma and lack of knowledge associated with mental health issues that creates reluctance on the part of clinicians to recognise distress and in patients seeking help. The research suggests that practice nurses frequently share those attitudes to mental health to some degree. However, based on pre- and post-training surveys, participating PNs were able to achieve greater confidence in dealing with mental illness to the point where they were able to discuss thoughts of suicide with patients. Similarly, feedback from the patients participating in the TrueBlue study suggests that the relationship they are able to develop with the Practice Nurse may overcome their reluctance to seek assistance. 

Most importantly, comments from patients suggest that the use of PHQ-9 questionnaire allows patients to become more familiar with their condition(s) and develop a better understanding of the concept of mental illness. They expressed greater confidence in using an appropriate language to express their situation and to converse with clinicians.

Implications for policy

The TrueBlue study delivers proof of the concept that, with sufficient training and ongoing support (including template-based planning tools as well as continuous teleconference-based peer support), Practice Nurses can create appropriate and effective therapeutic relationships with those patients who have a depression diagnosis.

The study reinforces current research that the prevalence of depression in patients with chronic illnesses is significant. While screening patients on practice registers (diabetes and CHD) using two standard screening questions is part of the National Health Service of UK’s Quality and Outcomes Framework, and screening for depression is now recommended practice in the Australian Heart Foundation practice guidelines, it is timely that efforts continue for the inclusion of such screening in national diabetes guidelines. 


Morgan M, Dunbar J, Reddy P, Coates M, Leahy R. The TrueBlue study: is practice nurse-led collaborative care effective in the management of depression for patients with heart disease or diabetes? BMC Family Practice 2009;10:46-53.

Morgan M, Reddy P, Coates M, Leahy R, Schlicht K, Dunbar J. Practice nurses as case managers in a collaborative care model for managing depression among patients with heart disease or diabetes:  The D-TECT and TrueBlue studies in primary care. In: Larson A, Lyle D, editors. A Bright Future for Rural Health: Evidence-based policy and practice in rural and remote Australian Health Care: Australian Rural Health Education Network 2010:48-51. ISBN: 978-0-977-56873-4

Practice in Rural and Remote Australian Health Care: Editors Ann Larson and David Lyle: Australian Rural Health Education Network: 13 April 2010

Morgan M, Dunbar J, Reddy P. Collaborative Care: the role of practice nurses. Australian Family Physician 2009;38(11):925-26

Schlicht K, Morgan MAJ, Fuller J, et al. Safety and acceptability of practice-nurse-managed care of depression in patients with diabetes or heart disease in the Australian TrueBlue study. BMJ Open 2013;3:e002195. doi:10.1136/bmjopen-2012-002195

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