ABSTRACT FROM: Coventry P, Lovell K, Dickens C, et al. Integrated primary care for patients with mental and physical multimorbidity: cluster randomised controlled trial of collaborative care for patients with depression comorbid with diabetes or cardiovascular disease. BMJ 2015;350:h638.
Collaborative care, a treatment model in which a specialist mental health provider collaborates with primary care, often assisted by a care manager, aims to improve the management of depression, including depression comorbid with medical conditions.1 There is recent evidence from the TEAMcare trial in the USA that integrating depression management and the management of diabetes and cardiovascular disease achieves better outcomes for both.2
This study was a randomised trial in which patients were allocated to an intervention in clusters (by general practice). Patients had to have a Patient Health Questionaire-9 (PHQ-9) depression score of 10 or more for at least 2 weeks, diabetes or heart disease to be eligible to participate. Patients who had severe psychiatric illness or who were receiving palliative care were excluded. In total, 39 clusters in the north west of England, including 387 patients were randomised. Telephone interviews were used to collect primary outcome data only among patients who declined a face-to-face follow-up assessment; 37 (9.6%) patients had missing data for the primary outcome.
The intervention being tested was not the same as collaborative care evaluated in the US trials but a rather a low-cost version adapted for the UK National Health Service (NHS). It comprised psychological treatment delivered by Improving Access to Psychological Therapies (IAPT) workers with limited linkage with primary care practice nurses. The treatment did not include overall management by a psychiatrist. Also, the IAPT workers did not manage the diabetes as the care managers did in the TEAMcare trial. The comparator was usual care and the primary outcome was depression severity measured on the Symptom Checklist (SCL) self-rated depression scale at 4 months.
Allocation of general practices was by minimisation with allocation concealment. It was not possible to blind patients or general practitioners because of the nature of the intervention, although an attempt was made to collect outcome data blind. The follow-up period was 4 months.
This trial found a modest (effect size 0.3) benefit of collaborative care over usual care (standardised mean difference −0.30, 95% CI −0.54 to −0.07).
There was greater patient satisfaction with collaborative care (mean difference on the Client Satisfaction Questionnaire of 0.32, 95% CI 0.19 to 0.45).
The trial indicates modest benefit from this version of collaborative care, but it did not test the type of collaborative care used in the TEAMcare trial.
The treatment was short-term IAPT therapy not psychiatrist-directed depression management.
Despite the use of self-reported questionnaires and masking of research staff to allocation, all outcome data were collected face-to-face at follow-up, and researchers might have been made aware of treatment allocations, leading to possible assessment bias.
The treatment for depression was not well integrated with the patient's medical care. In the TEAMcare trial a single care manager provided help for both diabetes and depression. In this trial the depression management was separate from the diabetes management; the IAPT depression therapist had only limited contact with the practice nurse.
The trial follow-up was to only 4 months after randomisation.
The authors should be congratulated for successfully conducting this large trial of collaborative care using the existing resources of the UK NHS and showing feasibility of the approach. It is likely; however, that the small effect observed would have been much larger had a more intensive management system been implemented, as in the Symptom Management Research Trials in Oncology (SMaRT Oncology trials) of treatment for depression in patients with cancer.3 We need UK-based trials for depression and diabetes that evaluate this more intensive approach.
These results offer an encouraging feasibility study but are unlikely to change practice as the effects are too small. The main implication is that if we are to deliver highly effective integrated collaborative care management for depression comorbid with medical illnesses, this approach is feasible but we need to to invest in more intensive integrated treatment programmes.
Competing interests: None declared.
Katon W, Unutzer J, Wells K, et al. Collaborative depression care: history, evolution and ways to enhance dissemination and sustainability. Gen Hosp Psych 2010; 32:456–64. Katon WJ, Lin EH, Von Korff M, et al. Collaborative care for patients with depression and chronic illnesses. N Engl J Med 2010; 363:2611–20. Sharpe M, Walker J, Holm Hansen C, et al. Integrated collaborative care for comorbid major depression in patients with cancer (SMaRT Oncology-2): a multicentre randomised controlled effectiveness trial. Lancet 2014; 384:1099–108. 
