P1259250303LVAWG

1
Rapid Penetration of COX2 Inhibitors in
Non-Steroidal Antiinflammatory Drug Market an
Implication to Hospital Cost Containment Policy
Supon Limwattananon, MPHM, PhD Chulaporn
Limwattananon, MPharm, MSc, PhD Supasit
Pannarunothai, MD, PhD Faculty of
Pharmaceutical Sciences, Khon Kaen University
Center for Health Equity Monitoring, Naresuan
University - Thailand
2
Cyclo-Oxygenase-2 (COX2) Inhibitors

• In Thailand,
• Celecoxib and Rofecoxib have been available since
  1999,
• each by a sole pharmaceutical company
• single-source product
• Report from MOPH-provincial hospitals (N 41,
  Year 2002),
• Spending for COX2
  inhibitors
• Total acquisition costs 42.9 million Baht
• Share of top 50 high cost drugs 6.2
• Ranking
• Celecoxib 1st (in secondary care hospitals)
• 3rd (in tertiary care hospitals)

3
Objectives
1. To examine variations in hospital NSAID
expenditures as related to the use of COX2
inhibitors 2. To assess patterns of drug
channeling for COX2 inhibitors
4
Study Population

• Settings 18 provincial hospitals in 4 regions of
  Thailand
• (secondary and tertiary acute care
  settings)
• Sample 1,558,633 prescriptions for oral NSAID
  solid forms
• rendered to ambulatory patients in 4 health
  insurance schemes
• Civil Servant Medical Benefit Scheme-CSMBS
• Social Security Scheme-SSS
• Low-Income Card Universal Health Care
• Coverage-LIC/UC schemes
• Rest of the population-ROP
• Time periods Fiscal years 2000-2002

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Study Design Analysis

• Retrospective, secondary analysis of electronic
  databases
• of hospital drug use
• Statistical analysis
• For drug expenditures a generalized linear
  model (GLM)
• For propensity of drug use logistic regression
  analysis
• Control for the underlying differences in drug
  use patterns due to
• patient demographics (age groups and sex)
• years of drug use (and interaction with health
  insurance schemes)
• hospital settings
• (proxy for variations in prescribing practice
  styles)

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Utilization and Expenditures All Types of NSAIDs
Prescriptions Daily doses Thai
Baht Year 2000 484,452 4,944,285 23,205,944
Year 2001 549,366 5,658,362 34,257,243 An
nual growth from Year 2000 (13.4)
(14.4) (47.6) Year 2002 538,517
5,260,404 37,991,221 Annual growth from Year
2000 (11.2) (6.4) (63.7)
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Daily Doses by Types of NSAID
Days
5.2
8.2
10.0
0.7
COX2 inhibitors
Other NSAID-NED
Meloxicam
Other NSAID-ED
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Expenditures by types of NSAID
Baht
COX2 inhibitors
33.9
52.1
46.5
6.5
Other NSAID-NED
Meloxicam
Other NSAID-ED
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Factors Affecting NSAID Expenditures per Capita
(Competing Models)
Model with interaction terms
Main effect model Coefficienta P value
Coefficienta P value COX2 inhibitors
2.486 lt 0.001 2.488
lt 0.001 Age 36 49 years b 0.368
lt 0.001 0.370 lt 0.001 Age 50 years b
0.798 lt 0.001
0.805 lt 0.001 Male - 0.158 lt
0.001 - 0.158 lt 0.001 CSMBS c 0.864
lt 0.001 0.847 lt 0.001 LIC/UC c
- 0.001 0.954 - 0.053 lt
0.001 ROP c - 0.022 0.188 -
0.084 lt 0.001 Year 2001 d - 0.035
0.065 0.038 lt 0.001 Year 2002 d
0.186 lt 0.001 0.025
0.002 CSMBS x Year 2001 0.083
0.002 CSMBS x Year 2002 - 0.093 lt
0.001 LIC/UC x Year 2001 0.123 lt
0.001 LIC/UC x Year 2002 - 0.205 lt
0.001 ROP x Year2001 0.070
0.002 ROP x Year2002 - 0.249 lt 0.001 a
Based on generalized linear model (GLM) using log
link, gamma distribution , adjusted for hospital
indicators b Age of 18-35 years as the reference
category c SSS as the reference category d Year
2000 as the reference category
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Effects on Difference in NSAID Expenditure
difference a 95
CI COX2 inhibitors 1,101.2
1,056.5 to 1,147.6 vs. other NSAID Age 36-49
years 44.5 42.3 to
46.7 vs. 18-35 years Age 50 years 122.0
118.5 to 125.6 vs. 18-35 years Male
-14.6 - 15.7 to -13.5 vs.
Female a difference due to an indicator
variable exp(Coefficient) - 1
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Effects on Difference in NSAID Expenditure
(Trends for Each Scheme)
difference a LIC/UC
SSS ROP CSMBS Year 2001 vs. 9.2
-3.4 3.5 4.9 Year 2000 Year 2002 vs.
-1.9 20.4 -6.1
9.7 Year 2000 a difference due to an
indicator variable exp(Coefficient) - 1
Based on GLM with interaction of schemes and years
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Effects on Difference in NSAID Expenditure
(Comparison between Schemes for Each Year)
difference a Year 2000
Year 2001 Year 2002 CSMBS vs.
SSS 137.2 157.7
116.1 ROP vs. SSS -2.2 4.9
-23.7 LIC/UC vs. SSS -0.1 13.0
-18.6 a difference due to an indicator
variable exp(Coefficient) - 1 Based on GLM
with interaction of schemes and years
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Propensity to Receive COX2 Inhibitors (Competing
Models)
Model with interaction terms
Main effect model Coefficienta P value
Coefficienta P value Age 36 49 years b
0.619 lt 0.001 0.617 lt 0.001 Age
50 years b 1.267 lt
0.001 1.270 lt 0.001 Male - 0.302
lt 0.001 - 0.301 lt 0.001 CSMBS c
2.279 lt 0.001 2.434 lt 0.001 LIC/UC
c - 0.845 lt 0.001
- 0.585 lt 0.001 ROP c - 0.407 lt 0.001
0.178 lt 0.001 Year 2001 d 1.105
lt 0.001 1.200 lt 0.001 Year 2002 d
1.145 lt 0.001 1.512 lt
0.001 CSMBS x Year 2001 - 0.009
0.936 CSMBS x Year 2002 0.303
0.003 LIC/UC x Year 2001 0.367
0.009 LIC/UC x Year 2002 0.285
0.038 ROP x Year2001 0.461 lt 0.001 ROP
x Year2002 0.853 lt 0.001 a Based on
logistic regression analysis, adjusted for
hospital indicators b Age of 18-35 years as the
reference category c SSS as the reference
category d Year 2000 as the reference category
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Odds Ratio of Receiving COX2 Inhibitors(Compariso
n between Schemes for Each Year)
Odds Ratio a Year 2000
Year 2001 Year 2002 CSMBS vs.
LIC/UC 22.74 15.62 23.14 CSMBS vs. SSS
9.77 9.68 13.22 ROP vs. LIC/UC 1.55
1.70 2.73 LIC/UC vs. SSS 0.43 0.62
0.57 a Based on logistic regression model with
interaction of schemes and years
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Odds of Receiving COX2 Inhibitors
CSMBS
Odds (in log scale)
SSS
ROP
LIC/UC
Odds exp(constantbAgebGenderbSchemebYearb
SchemexYearbHosp)
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Conclusion

• Growth in NSAID expenditures was largely driven
  by
• rapid penetration of the expensive COX2
  inhibitors.
• The prime target for the patent-protected,
  single-source drugs
• was patients covered by fee-for-service scheme
  like CSMBS.
• To contain hospital drug costs, a generic
  substitution for
• COX2 inhibitors is unfeasible due to market
  exclusivity nature.
• Therapeutic substitution with the multi-source
  NSAID is
• a viable alternative in curbing the
  expenditure growth.