The
e Effect
ect o
of tthe
e Part
atD
Coverage Gap on Medicare
B
Beneficiaries
fi i i using
i
Antidepressants
Mary Price
AcademyHealth Annual Research Meeting
June 29, 2009
Study
y Team
Mary Price, MA1
Jie Huang, PhD1
Richard Brand, PhD2
Vicki Fung, PhD1
Bruce Fireman, MA1
Rita Hui, PharmD1
Joseph Newhouse, PhD3
John Hsu, MD MBA MSCE1
1 Kaiser
K i
Permanente
P
Center
C
for
f Health
H l h Policy
P li Studies
S di and
d the
h Di
Division
i i off
Research
2 University of California, San Francisco
3 Harvard University
Funding Support: National Institute on Aging
No other relevant financial relationships
p to disclose
2
Background:
g
Drug
g Coverage
g

Medicare Part D drug benefits were introduced in the
U.S.
U S in 2006

Plan D plans often include substantial and complex
forms of cost
cost--sharing,
sharing including a gap in coverage
between $2,250 in total drug costs and $3,600 in outout-of
of-pocket costs in 2006

Evidence suggests that patients reduce use of both
necessary and unnecessary medications when faced
with substantial costcost-sharing

Beneficiaries who require chronic treatment regimens
may be particularly vulnerable to gaps in drug coverage
3
Background:
g
Depression
p

Antidepressants are one of six drug classes specifically protected
under Part D, meaning that nearly all drugs within the class must be
included on plan formularies

Although protected, these antidepressants are still subject to costsharing

In the United States, nearly 1 in 6 people over the age of 65 have
some level of clinical depression

Depression in the elderly is associated with negative health
outcomes


Depression is associated with an increased risk of cardiac diseases and
has been linked to increased severity of heart attacks and to stroke and
osteoporosis
Patients with depression are likely to have drug costs associated with
the treatment of other conditions, and as a result, may be even more
likely to reach coverage limits
4
Objectives
j
In a co
cohort
o o
of Medicare
ed ca e pa
patients
e s receiving
ece g
antidepressants, we investigated the impact
of the Medicare Part D drug coverage gap
on:




Patient outout-of
of--pocket costs
Drug spending
Measures of drug use
Visit Rates
5
Methods

Design: Historical cohort study in 2006

Study population:


Medicare members (65+ years old) of a large prepaid, integrated
delivery system
Comparison
p
g
groups:
p
• Gap: Individual subscribers facing a coverage gap
• No Gap: EmployerEmployer-sponsored benefits and no coverage gap
(concurrent controls)


Medicaid and low
low--income subsidy patients excluded
Three cohorts:

Main Cohort (N=48,626):
(N 48,626): Received at least one antidepressant
drug in baseline year (2005)
• Subgroup (N=17,938): Subjects that also had a depression
diagnosis in 2005

New Users (N=7,805):
(N=7 805): Received an antidepressant in the first 6
6-months of 2006, but not in 2005
6
Drug Use and Diagnoses in 2005
No Depression
Diagnosis
Depression
Diagnosis
Total
No Antidepressant Use
214,705
4,123
218,828
(82%)
Antidepressant Use
30,688
17,938
48,626
(18%)
Total
245,393
(92%)
22,061
(8%)
267,454
(100%)
Among Medicare members (age 65+ years old) of a large prepaid,
integrated delivery system in January, 2006.
7
Outcome Measures

Monthly Patient OutOut-of
of--Pocket (OOP) Costs: Overall
and
a d Antidepressants
dep essa s

Monthly Drug Spending: Overall and Antidepressants

Antidepressant Drug Use:





Proportion days covered (PDC) = Days Supply / Time Covered
Had consistent drug use if PDC >= 80%
Main Cohort: Monthly Drug Use
New Users in 2006: Drug Use (adherence) in the first 66-months
after 1st antidepressant prescription
Monthly Visit Rates: ED, Office, NonNon-elective
Hospitalizations
8
Statistical Analysis

Drug Spending and Patient OutOut-of
of--Pocket Costs:


Drug Use:



Main
M i C
Cohort:
h t L
Logistic
i ti regression
i with
ith a random
d
subject
bj t effect
ff t
New Users in 2006: Logistic regression
Visit Rates:


Linear regression with a random subject effect
Poisson regression with a random subject effect
Covariates:

Age, gender, race/ethnicity, socioeconomic status (2000 US
Census) comorbidity (DxCG score),
Census),
score) medical center,
center office
copayment, month
9
Results

Among all subjects, 74% had at least one antidepressant
dispensed
p
in 2006



A
Among
subjects
bj
that
h also
l h
had
dad
depression
i di
diagnosis
i iin
2005, 82% had at least one antidepressant dispensed in
2006



73% of subjects with a gap
76% of subjects without a gap
81% of subjects with a gap
84% of subjects without a gap
23% off subjects
bj t reached
h d the
th gap th
threshold
h ld ($2250) iin
2006


16% of subjects with a gap
31% of subjects without a gap
10
Study Population
Total
Gap
No Gap
48,626
26,364
22,262
% Female
69%
72%
67%
Mean Age
75.2
75.4
75.0
Mean DxCG Score
1.10
1.07
1.14
Mean PDC in 2005
78%
78%
78%
47,667
25,681
21,986
Asian ((% known))
5%
5%
5%
Black (% known)
4%
2%
6%
Hispanic (% known)
7%
8%
6%
Other (% known)
3%
3%
3%
White (% known)
81%
82%
80%
48,476
26,279
22,197
High SES (% known)
84%
84%
85%
Low SES (% known)
16%
16%
15%
Subjects
Subjects with Known Race
Subjects with Known SES
11
Monthly Drug Costs:
Gap
p vs. No Gap
p
All Subjects
Difference
($)
(95% CI)
Subjects with a
Depression Diagnosis
Difference (95% CI)
($)
Antidepressant
p
Drug Spending
-4.21
4 21
(-4.97,
4 97 -3.44)
3 44)
-7.86
7 86
(-9.54,
9 54 -6.17)
6 17)
OOP Antidepressant
Drug
g Cost
3.26
(3.07, 3.45)
4.95
(4.53, 5.37)
Total Drug Spending
-56.10
(-62.37, -49.82)
-68.36
(-77.95, -58.83)
Total OOP Drug Cost
31.29
(30.08, 32.50)
35.19
(33.11, 37.27)
p – No Gap
p
Difference = Gap
12
Antidepressant Drug Use:
Gap
p vs. No Gap
p
Consistent drug use among all subjects
Consistent drug
g use among
g subjects
j
with a
depression diagnosis
Adherence during the initial treatment period
(first 66-months) among new users
OR
(95% CI)
0.76
(0.69, 0.83)
0 73
0.73
(0 63 0
(0.63,
0.85)
85)
0.89
(0.80, 0.98)
OR = Odds in Gap / Odds in No Gap
13
Monthly Relative Visit Rates:
Gap
p vs. No Gap
p
All Subjects
Subjects with a
Depression Diagnosis
RR
(95% CI)
RR
(95% CI)
Office Visits
0.93
(0.91, 0.95)
0.92
(0.89, 0.96)
Non-Elective
NonHospitalizations
1.02
(0.95, 1.09)
1.00
(0.89, 1.13)
All ED Vi
Visits
it
1 01
1.01
(0 96 1
(0.96,
1.06)
06)
1 09
1.09
(1 01 1
(1.01,
1.18)
18)
Mental Health ED
Visits
1.14
(0.84, 1.54)
1.17
(0.77, 1.77)
RR = Rate in Gap / Rate in No Gap
14
Limitations
 Non
Non--random
 No
allocation of drug coverage
measures of outout-of
of--system
y
drug
g use
 No
assessment of the clinical
appropriateness of prescribing
 Single
integrated delivery system
15
Conclusions

Nearly oneone-inin-six beneficiaries using antidepressants
reached the Part D coverage gap in 2006

Monthly outout-of
of--pocket costs were higher in the gap vs.
non--gap group
non
group, but the gap was associated with lower
drug spending overall and for antidepressants

Consistent antidepressant drug use was lower among
beneficiaries with a coverage gap as was adherence in
the initial treatment period

While the gap was associated with lower office visit
rates, it was associated with higher ED visit rates
among subjects with a depression diagnosis
16
Implications
p

Despite protections, antidepressants are still subject to
high levels of costcost-sharing which we found to be
associated with decreased antidepressant spending and
consistent drug use, and possibly with increased rates of
adverse events

Future work will evaluate the effects of drug benefit gaps
with additional years of data

Changes before and after reaching the gap threshold will
also be examined

Need to monitor program effects to determine safe and
effective ways of providing Medicare Part D drug
benefits
17
Thank you!
y
18
Additional Slides
19
Timing of the First Antidepressant
Dispensed
p
in 2005
Total
Gap
No Gap
January
64%
63%
66%
February
5%
5%
5%
March
5%
5%
5%
April
4%
4%
4%
May
3%
4%
3%
June
3%
3%
3%
July
3%
3%
3%
August
3%
3%
3%
September
3%
3%
3%
October
3%
3%
2%
November
2%
3%
2%
December
2%
2%
2%
20
Antidepressants Dispensed in 2006
Total
Dispensings
% of
Dispensings
% Generic
157,512
100%
94%
Bupropions
8,569
5%
98%
SNRIs
4,959
3%
7%
SSRIs
77,847
49%
95%
TCAs
38,556
24%
100%
Other
27,581
18%
99%
21
Antidepressants: Days of Supply
Days of Supply
n
%
<30
3 596
3,596
2%
30
17,828
11%
31--49
31
4,797
,
3%
50
15,044
10%
84
0%
60
8,579
5%
61--99
61
5,295
3%
100
102 209
102,209
65%
>100
80
0%
51--59
51
M
Mean
= 81 d
days
22