Associations Between Prior
Authorization and Health Services
Use Among Medicaid Patients
with Bipolar Disorder
Lu CY, Adams AS, Ross-Degnan D,
Zhang
a g F,, Zhang
a g Y,, Soumerai
Sou e a SB
S
1
Acknowledgments

Funding/Support:
g/ pp


Robert Wood Johnson Foundation’s Changes in Health
Care Financing and Organization Program (PI: S.
Soumerai)
CL: Pharmaceutical Policy Research Fellowship (HMS),
Sir Keith Murdoch Fellowship (AAA), Public Health
Training Fellowship (NHMRC)
This study was conducted at the Department of
Population Medicine, Harvard Medical School &
Harvard Pilgrim Health Care Institute.
2
Background & Research questions

Maine Medicaid:

July 2003 – Prior Authorization (PA) for non-preferred
atypical antipsychotics (AA) and anticonvulsants (AC)
Among patients with bipolar illness initiating a new
treatment episode
episode, what was the association between PA
policy and:

1
1.
Medication discontinuation?
2.
Subsequent outpatient (ER, psychiatric) visits?
3
Methods

Study population



Diagnosed bipolar disorder
Newly treated: (i) no bipolar drugs & (ii) <45 days
institutionalized in the 90 days before initial drug
dispensing (index date)
Cohorts: stratify by receipt of care at
Community Mental Health Centers (CMHC)

CMHC attenders (2+ visits in baseline period)



Policy (Jul 2003 – Feb 2004)
Pre-policy
Pre
policy (historical; Jul 2002 – Feb 2003)
Non-attenders


Policyy
Pre-policy
4
Methods

Data: Maine Medicaid claims data (2001-2004)

Outcome measures:


Time to medication discontinuation
Changes in outpatient visits (ER, psychiatric) pre & postinitiation in policy cohort vs.
vs pre-policy cohort


3 time periods: pre-initiation, post-initiation on treatment, postinitiation after discontinuation
Statistical analysis:


Extended Cox regression analysis (≤30 days vs. >30
days)
Linear mixed models
5
Baseline Characteristics
Pre-policy cohort
Policy cohort
Attenders
Non attenders
Non-attenders
Attenders
Non attenders
Non-attenders
Female %
63
67
65
63
Aged 18-34 %
45
51*
49
56
Aged 35-54 %
50
41
45
39
Bipolar Rx used: AA
25
11*
26
12*
AC
30
17*
27
16*
Schizophrenia %
17
5*
16
6*
No. medications
7.04.6
5.74.6*
7.45.1
5.64.5*
10
3*
11
4*
2 42 6
2.42.6
0 71 5*
0.71.5
2 22 1
2.22.1
0 71 3*
0.71.3
(n=275)
Psych hospitalization %
Psych visits
* p<0.05 between groups
(n=739)
(n=275)
(n=671)
6
Impact
p
on Drug
g Discontinuation
CMHC
attenders:
HR= 1.73
(95% CI 1.02.9)
Nonattenders:
tt d
HR= 1.30
(95% CI 1.01 6)
1.6)
7
Psych
y visits (p
(per patient
p
per
p month))
P1 vs P0
= 0.09
CMHC attenders:
P2 vs P0
= -0.55
Estimate=
E
ti t
-0.64
0 64
(95% CI
-1.26 to -0.03)
Non-attenders:
Estimate 0.14
Estimate=
(95% CI
-0.18 to 0.46)
ER visits (p
(per patient
p
per
p month))
CMHC attenders:
P1 vs P0
= -0.05
Estimate=
E
ti t
0
0.06
06
(95% CI
-0.13 to 0.24)
P2 vs P0
= 0.10
Non-attenders:
Estimate 0.16
Estimate=
(95% CI
0.05 to 0.26)
Summary

P i Authorization
Prior
A th i ti policy
li was associated
i t d with:
ith




Increased medication discontinuation
Seriously ill: Decline in psychiatric visits (less reason to
visit physicians after discontinuation)
Less seriously ill: Increased ER visits (attempts to
manage medication access issues)
Long-term consequences of PA? Further research!
10