The CASPER+ trial: is collaborative care clinically effective and cost effective for older adults with depression in primary care?

Problem

Depression among older people in primary care is common and often co-exists with long term health problems. This group of people are often identified through screening and case finding where they ‘screen positive’ to incentivised questionnaires such as the PHQ9. Management of older people with depression is often limited, since IAPT services focus on working age adults and older peoples’ mental health services do not have sufficient capacity. Primary care management often involves the use of antidepressant medication, but compliance is poor and there is little access to psychosocial interventions. Collaborative care is a primary care-based organisational approach using case managers to improve the use of medication and to deliver evidence-supported psychological therapy.

Collaborative Care has been trialled in non-UK settings and could be potentially be adapted for older people with depression. NICE guidelines have previously recommended that large scale trials of this approach be undertaken. The NIHR Health Technology Assessment Programme commissioned such a trial to address this evidential gap. We present the initial results of the Collaborative Care for Screen-positive Elders-PLUS (CASPER trial ISRCTN45842879).

Approach

We conducted a large scale pragmatic two arm trial in 62 GP practices of 485 adults aged 65+ with DSM-IV Major Depressive Disorder. Participants were randomised to either collaborative care with provision of evidence-supported psychological therapy (behavioural activation) and medication management or usual GP care alone (control condition). The primary outcome was depression severity (PHQ9) at four months post-randomisation. Secondary outcomes included anxiety (GAD7), somatisation (PHQ15), health-related quality of life as measured by the SF-12 at four, 12 and 18 months. We also conducted a concurrent economic evaluation.

Findings

The primary endpoint at four months favoured Collaborative Care (mean difference: 1.92 PHQ9 score points, 95% CI: 0.85 to 2.99, p<.001) equivalent to a moderate standard effect size of 0.34. Treatment differences were however not maintained at 12 or 18 months. There were statistically significant improvements in anxiety, reduced somatisation and improved quality of life. Overall, the mean cost per incremental QALY compared to usual care was £26,016, however, for participants attending six or more sessions it appears to represent better value for money (£9,876/QALY).

Consequences

There is relatively little research to inform the provision of primary care for older adults with depression. The results of the CASPER+ trial show that collaborative care is effective across a range of short term outcomes in this group. More research is needed to establish if and how benefits can be sustained. The CASPER+ trial is the largest UK trial to date for older people with depression, and are likely to inform forthcoming NICE guidelines in this area (currently under revision).