Effectiveness &
Cost-Effectiveness of
Collaborative Care Depression
Treatment in Veterans
who screen positive for PTSD
Domin Chan, MHS, PhC
Northwest HSRD Center of Excellence
VA Puget Sound Healthcare System,
University of Washington,
Seattle, Washington, USA
Funded by VA HSR&D
Objective
• To evaluate the effect of Collaborative
Care on depression severity &
functional status (Hedrick et al.)
• To evaluate the cost-effectiveness of
Collaborative Care (Liu et al.)
• Among depressed VA primary care
patients who screen positive for
post-traumatic stress disorder (PTSD)
Background
Depression & PTSD are:
• Highly prevalent illnesses in Veterans
– 36-51% depressed veterans have PTSD
• Underdiagnosed and undertreated
Depression & comorbid PTSD
are associated with:
• Greater functional impairment
• Higher risk of suicidal behavior
Study Design
• Design: Group-Randomized Trial
(by provider group)
• Setting: General Internal Medicine clinic,
Seattle VA Medical Center
• Telephone interviews at 3 and 9 months to
assess clinical outcomes
(87-88% retained at 9 months)
• Inclusion: major depression or dysthymia
• Exclusion: acute suicidality, psychosis, bipolar
disorder or primary diagnosis of PTSD
PTSD Classification
• Experienced at least one trauma
and 2 out of 3 PTSD symptoms:
– Re-experiencing trauma
– Increased arousal
– Detachment or avoidance
• Sample:
54% depressed Veterans
screened PTSD positive
Study Sample
338
Depressed
Patients
Collaborative
Care
n=175
PTSD +
n=87
PTSD n=73
R
Usual Care
n=163
PTSD +
n=96
PTSD n=82
® Patients were randomized by provider group
Treatment for Depression
Usual Care
– Provider notification of
depressed patients
– Patient education
materials available
– PCP consults or refers
to mental health
specialist
– Mental health available
in primary care
Collaborative Care
– Mental health team
provides patient
assessment & treatment
plan to providers
– Patient education
materials sent to patients
– Cognitive Behavioral
Therapy (Group)
– Social worker phoned
patients to encourage
adherence on a regular
schedule
Outcome Measures
• Depression Symptoms:
Hopkins Symptom Checklist (SCL-20)
Depression-Free Days
• Social/Role Functioning:
Sheehan disability scale
Cost Measures
• Outpatient Services
– Depression Treatment
• Antidepressant prescriptions
• Primary care visit with depression
diagnosis
• Mental health specialty care
• Collaborative care intervention costs
– Other outpatient services
• Inpatient Care
• Total Health Services
Analysis
Effectiveness
Cost-effectiveness
• ICER = Δ costs
Δ effectiveness
• Cost per additional
– Provider group
depression-free day
random effects
• Logistic regression for
– Independent
probability of
variables fixed effects
depression-free day
• Adjusted for provider
• Gamma GLM
clustering
regression for costs
• Bootstrap standard
errors (1000 reps)
• Mixed Effects
Regression
Baseline Patient Characteristics
PTSD +
(n=158)
55
PTSD (n=139)
62
Pvalue
<.001
Chronic disease (CDS)
3.18
4.04
0.017
Depression (SCL-20)
2.10
1.60
<.001
33
34
N.S.
32
5.90
38
5.02
<.001
0.002
Mean
Age
SF-36 Physical (PCS)
SF-36 Mental (MCS)
Sheehan Disability
Note: CDS, SCL & Sheehan – higher scores are sicker
PCS & MCS – lower scores are sicker
Adjusted Clinical Outcomes
SCL Depression Score
Collaborative
Care Effect
P-value
3 months
-0.22
N.S.
9 months
-0.27
0.02
3 months
-0.63
N.S.
9 months
-0.92
0.03
Sheehan Disability Score
Adjusted for: age, sex, race, education, marital status, living alone, baseline
chronic disease, baseline SCL & previous year’s antidepressant use
Adjusted Incremental Cost
& Cost-Effectiveness
Collaborative care: 17.5 more depression-free days
Cost Type
Incremental
Cost
($)
Mean
Cost per
additional
depressionfree day ($)
95% CI Mean
95% CI
Depression Treatment
Costs
323
128-579
22.8
4-103
Total Outpatient Costs
383
N.S.
38.2
N.S.
Total Costs
-80
N.S.
147
N.S.
Conclusions
For depressed Veterans
who screen positive for PTSD:
– Collaborative care treatment is effective in
reducing depression symptoms by 9 months,
but not at 3 months, compared to enhanced
usual care
– Collaborative care improves social
functioning at 9 months, but not at 3 months
– Collaborative care impact takes longer
Conclusions
For depressed Veterans who screen
positive for PTSD:
– Collaborative care results in moderate
increase in costs in order to achieve
improved outcomes
Policy Implications
For treatment of depressed Veterans
with PTSD symptoms:
– Integration of primary care providers and
mental health specialists, supportive
patient care management may be
effective in reducing depression
symptoms at a moderate cost
Acknowledgements
Co-Authors:
– Chuan-Fen Liu, PhD
– Ed Chaney, PhD
– Gayle Reiber, PhD
– Lori Zoellner, PhD
– Susan Hedrick, PhD