title: Collaborative care for depression in UK primary care: a randomized controlled trial.
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.
  
  
  METHODS
  We undertook a Phase II patient-level randomized controlled trial in primary care, nested within a cluster-randomized 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.
authors.affiliation: Department of Health Sciences, University of York, UK. dr17@york.ac.uk
authors.forename: D A
authors.initials: DA
authors.lastname: Richards
authors.forename: K
authors.initials: K
authors.lastname: Lovell
authors.forename: S
authors.initials: S
authors.lastname: Gilbody
authors.forename: L
authors.initials: L
authors.lastname: Gask
authors.forename: D
authors.initials: D
authors.lastname: Torgerson
authors.forename: M
authors.initials: M
authors.lastname: Barkham
authors.forename: M
authors.initials: M
authors.lastname: Bland
authors.forename: P
authors.initials: P
authors.lastname: Bower
authors.forename: A J
authors.initials: AJ
authors.lastname: Lankshear
authors.forename: A
authors.initials: A
authors.lastname: Simpson
authors.forename: J
authors.initials: J
authors.lastname: Fletcher
authors.forename: D
authors.initials: D
authors.lastname: Escott
authors.forename: S
authors.initials: S
authors.lastname: Hennessy
authors.forename: R
authors.initials: R
authors.lastname: Richardson
mesh_terms: D000328:Adult; D003299:Cooperative Behavior; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000628:therapy*; D008605:Mental Health Services / Q000458:organization & administration; D010348:Patient Care Team; D011320:Primary Health Care / Q000379:methods*; D016896:Treatment Outcome; D006113:United Kingdom; D000078329:Workforce