title: Long-term effects of a collaborative care intervention in persistently depressed primary care patients.
abstract: OBJECTIVE
  A previous study described the effect of a collaborative care intervention on improving adherence to antidepressant medications and depressive and functional outcomes of patients with persistent depressive symptoms 8 weeks after the primary care physician initiated treatment. This paper examined the 28-month effect of this intervention on adherence, depressive symptoms, functioning, and health care costs.
  
  
  METHODS
  Randomized trial of stepped collaborative care intervention versus usual care.
  
  
  METHODS
  HMO in Seattle, Wash.
  
  
  METHODS
  Patients with major depression were stratified into severe and moderate depression groups prior to randomization.
  
  
  METHODS
  A multifaceted intervention targeting patient, physician, and process of care, using collaborative management by a psychiatrist and a primary care physician.
  
  
  RESULTS
  The collaborative care intervention was associated with continued improvement in depressive symptoms at 28 months in patients in the moderate-severity group (F1,87 = 8.65; P =.004), but not in patients in the high-severity group (F1,51 = 0.02; P =.88) Improvements in the intervention group in antidepressant adherence were found to occur for the first 6 months (chi2(1) = 8.23; P <.01) and second 6-month period (chi2(1) = 5.98; P <.05) after randomization in the high-severity group and for 6 months after randomization in the moderate-severity group(chi2(1) = 6.10; P <.05). There were no significant differences in total ambulatory costs between intervention and control patients over the 28-month period (F1,180 = 0.77; P =.40).
  
  
  CONCLUSIONS
  A collaborative care intervention was associated with sustained improvement in depressive outcomes without additional health care costs in approximately two thirds of primary care patients with persistent depressive symptoms.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Washington Medical School, Seattle, Wash 98195, USA. wkaton@u.washington.edu
authors.forename: Wayne
authors.initials: W
authors.lastname: Katon
authors.forename: Joan
authors.initials: J
authors.lastname: Russo
authors.forename: Michael
authors.initials: M
authors.lastname: Von Korff
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lin
authors.forename: Greg
authors.initials: G
authors.lastname: Simon
authors.forename: Terry
authors.initials: T
authors.lastname: Bush
authors.forename: Evette
authors.initials: E
authors.lastname: Ludman
authors.forename: Edward
authors.initials: E
authors.lastname: Walker
mesh_terms: D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use; D003266:Continuity of Patient Care / Q000191:economics; D003866:Depressive Disorder / Q000628:therapy*; D019468:Disease Management; D005260:Female; D017048:Health Care Costs; D006279:Health Maintenance Organizations; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011320:Primary Health Care; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents