Impact of an antidepressant
adherence program in a managed
care organization
Kara Zivin Bambauer, PhD
Stephen Soumerai, ScD
Alyce Adams, PhD
Fang Zhang, PhD
Rick Weisblatt, PhD
Neil Minkoff, MD
Andrea Grande, RPh
Dennis Ross-Degnan, ScD
Harvard Pilgrim Health Care and Harvard Medical School
Background

The burden of depression is substantial

Effective medications are available to treat
depression

Non-adherence to antidepressants remains a
substantial problem

Harvard Pilgrim Health Care (HPHC) sought to
improve quality of care for depression using
available electronic data
Objectives

To evaluate the effectiveness of providing faxed
feedback to physicians regarding patient refill
behavior

Does the proportion of patients who are potentially
non-adherent to treatment decrease after the policy?

Does the proportion of days within a treatment episode
without antidepressant coverage decrease after the
policy?
Content of Fax

Introduction: This is a clinical reminder to assist physicians who
are treating patients for Major Depressive Disorder (MDD)

Explanation: There are 3 quality of care measures for depression
treatment

Summary: information on antidepressant compliance
 Symptoms usually remit in 4-6 weeks
 Therapy should be continued for 6 months
 Only 40% of patients of patients adhere to antidepressant
treatment

Closing: Your patient (insert name) has gone more than 10 days
without antidepressant treatment (medication name, dose,
quantity)
Antidepressant Compliance Program
(ACP) Definitions

Adherent: antidepressant prescription refilled
within 10 days of an expected refill

If not, a fax is sent to the prescribing physician

Potentially non-adherent: antidepressant
prescription refilled more than 10 days and less
than 30 days after an expected refill

Failure: antidepressant prescription not refilled
within 30 days of an expected refill
Assumptions Underlying ACP

The prescribing physician receives the fax

The physician makes contact with the patient

A physician-patient conversation occurs that
effectively deals with the reasons for patient
non-adherence

The patient subsequently refills the antidepressant
prescription in a timely manner
Inclusion Criteria

All HPHC members were eligible

All types of providers were included

Each patient needed to be enrolled for 6 months before and 6
months after first antidepressant use

Patients were included who used a select subset of
antidepressants usually indicated for treatment of depression

New users of antidepressants (no use in previous 100 days)

First episode of antidepressant treatment for each person

Age ≥ 18
Timeline
5/15/2003
ACP begins
5/15/2002 - 2/14/2003
Pre-ACP period
5/15/2003 - 5/14/2004
First year of ACP
2/15/2003 - 5/14/2003
Phase-in period (data excluded from analysis)
Methods

Interrupted time-series (ITS) analysis
using SAS PROC AUTOREG



Used to evaluate rates of change in adherence
due to the ACP
Look at slope and level changes
ITS is one of the strongest
quasi-experimental designs for studying
policy changes
Characteristics of Study Participants
(N=13,128)



Mean age (sd): 42 (11)
Gender: 69% female
Policy Variables




Adherent: 18%
Potentially non-adherent: 29%
Failure: 53%
No significant differences in pre-policy and
post-policy patients
Percent of Non-Adherent Patients Who Proceed to
Adherence Failure
100%
Percent Adherence Failures
90%
80%
70%
60%
50%
Pre-ACP
period
First year of
ACP
40%
30%
20%
Phase-in
period
10%
0%
May-02 Aug-02 Nov-02 Feb-03 May-03 Aug-03 Nov-03 Feb-04 May-04
% w/gaps & fail
model
expected
Mean Percent of Treatment Days Not Covered
Percent Treatment Days Uncovered
100%
90%
80%
70%
60%
50%
Pre-ACP
period
First year of
ACP
40%
30%
20%
Phase-in
period
10%
0%
May-02 Aug-02 Nov-02 Feb-03 May-03 Aug-03 Nov-03 Feb-04 May-04
% coverage
model
expected
Limitations and Implications

Electronic reminder systems, while popular, may not
improve patient adherence

Success of such interventions requires a complex chain of
events to occur

We cannot determine from electronic data whether
communication between physicians and patients addresses
reasons for patient non-adherence

Stand alone interventions targeting adherence are not
successful
Conclusions

The ACP was not successful at increasing
antidepressant adherence rates in HPHC members

Additional research should re-examine assumptions
underlying the ACP to identify ways to improve
future antidepressant adherence interventions

Effectiveness of electronic interventions should be
carefully evaluated before widespread
implementation