Adherence to Antidepressant
Medications Among Health Plan
Members Diagnosed with Major
Depression
Ayse Akincigil, John R. Bowblis, Carrie Levin,
James T. Walkup, Saira Jan, Stephen Crystal
AcademyHealth 2006 Annual Research Meeting
Monday, June 26
Supported in part through NIMH grant R01 MH60831, AHRQ grants U18
HS016097 and HS-01182, and a grant by Horizon BCBSNJ
Background / Objectives
There is a large amount of evidence that
antidepressants are effective in reducing
symptoms of depression and preventing relapse;
however, poor adherence to medication is a
major obstacle to effective care.
We describe characteristics of patients at risk for
low adherence, and implications for policy and
practice.
Methods
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A retrospective, observational study of insurance
claims.
A large insurance company in Northeast, serving threemillion lives.
Data are constructed from insurance claims, between
January 2003 and January 2005.
Pharmacy claims are used to construct the outcome
measure -- refill persistence.
Medical claims are used to identify patients with a new
episode of depression.
Study Population
Index prescription date
Prescription look back period
90 days
Medication window
30
Diagnosis look back period
120 days
14
Index episode start date
(Date of Depression Diagnosis)
Outcome Measures
Index prescription date
Effective Acute Phase Treatment
114 days
Effective Continuation Phase Treatment
231 days
30
14
Index episode start date
Overall Rates of Refill
Persistence
60
50
40
27.4
% persistent
20
0
Acute Phase
Continuation Phase
Demographic, Socio-Economic
Characteristics
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Gender (67% female)
Age
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18-25 (11%)
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25-39 (32%)
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Median household
income at the
neighborhood (zipcode)
40-49 (28%)
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<50k (29%)
50-64 (26%)
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50k-70k (42%)
65 or older (4%)
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>70k (29%)
Comorbid Conditions
 Alcohol
Abuse (5%)
 Substance Abuse (8%)
 Anxiety Disorder (28%)
 Cancer (18%)
 Number of Cardiovascular Risk Factors
(18% suffer from one, 6% suffer from 2 or
more)
Care Patterns for Depression Episode
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Type of Provider on Initial Visit (49% were mental
health professional, 51% were general medical care).
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Initial antidepressant drug type (4% were on older
generation drugs).
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28% had a follow-up visit with a psychiatrist.
24% had a follow-up visit with another mental
health provider (e.g., psychologists, social workers).
General Use of Health and
Pharmacy Services
Number of Medications
Excluding Psychotropics
0 Medications
1-2 Medications
3-5 Medications
6 or more Medications
Number of Outpatient Visits
0 Visits
1-4 Visits
5 or More Visits
%
10.8
24.3
27.6
37.3
4.5
32.6
62.9
Predictors of Refill Persistence
in Acute Phase (1)
Income 70,000 +
1.22
Income 50,000-70,000
1.3
1
Income <50,000
1.95
Age 65 +
2.47
Age 50-64
1.71
Age 40-49
1.22
Age 25-39
1
Age <25
0
1
2
3
Predictors of Refill Persistence
in Acute Phase (2)
1.01
F/U with other MHP
No F/U with other MHP
1
F/U with a Psychiatrist
No F/U with a
1
0.69
Older Generation Drugs
Newer Generation Drugs
1
0.96
Gen Med Provider
MH Provider
1
0
1
1.18
Predictors of Refill Persistence
in Acute Phase (3)
0.65
# of Cardiovascular Risk Factors2+
0.98
# of Cardiovascular Risk Factors1
1
# of Cardiovascular Risk Factors 0
0.49
Alcohol Abuse
1
No Alcohol Abuse
0.72
Substance Abuse
1
No Substance Abuse
0
1
Predictors of Refill Persistence
in Acute Phase (4)
0.96
5+ Visits
1
1-4 Visits
0.75
0 Visits
1.7
6+ Meds
1.33
3-5 Meds
1.1
1-2 Meds
1
0 Meds
0
1
2
Non-Adherence Risk Factors for
0-8 Months (Continuation Phase)
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Males *
Younger age
Patients from low income neighborhoods
Comorbid substance abuse
Comorbid alcohol abuse
2+ CVD
Protective Factors
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F/U care from a psychiatrist
Number of medications other than psychotropics
Summary
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Adherence rates are low, problem worsens in continuation
phase.
Males, younger, and living in lower income neighborhoods
are particularly at risk.
No support to the scenario of “medication crowd-out”
among users of multiple medications.
Presence of multiple cardiovascular risk factors may crowd
out depression.
Depression care for those with comorbid substance abuse
and alcohol abuse are further complicated due to adherence
issues.
Having a follow up with a psychiatrist improves odds of
adherence.
Those who had follow up visits with social workers or
psychologists were equally likely to adhere, compared to
those with no follow up.