| dc.description.abstract | Background. Collaborative care is an effective intervention for depression which includes both organizational and
patient-level intervention components. The effect in the UK is unknown, as is whether cluster- or patient-randomization
would be the most appropriate design for a Phase III clinical trial.
Method. We undertook a Phase II patient-level randomized controlled trial in primary care, nested within a clusterrandomized
trial. Depressed participants were randomized to ‘collaborative care’ – case manager-coordinated medication
support and brief psychological treatment, enhanced specialist and GP communication – or a usual care control.
The primary outcome was symptoms of depression (PHQ-9).
Results. We recruited 114 participants, 41 to the intervention group, 38 to the patient-randomized control group and 35
to the cluster-randomized control group. For the intervention compared to the cluster control the PHQ-9 effect size was
0.63 (95% CI 0.18–1.07). There was evidence of substantial contamination between intervention and patient-randomized
control participants with less difference between the intervention group and patient-randomized control group (-2.99,
95% CI -7.56 to 1.58, p=0.186) than between the intervention and cluster-randomized control group (-4.64, 95% CI
-7.93 to -1.35, p=0.008). The intra-class correlation coefficient for our primary outcome was 0.06 (95% CI 0.00–0.32).
Conclusions. Collaborative care is a potentially powerful organizational intervention for improving depression treatment
in UK primary care, the effect of which is probably partly mediated through the organizational aspects of the
intervention. A large Phase III cluster-randomized trial is required to provide the most methodologically accurate test of
these initial encouraging findings. | en_GB |
