1. THOMSON SCIENTIFIC & HEALTHCARE ISPOR 11 th Annual International Meeting This study was funded by Pfizer, Inc. May 24, 2006 The Effects of Statin (HMG-CoA Reductase Inhibitor) Copayments and Statin Adherence on Medical Care and Expenditures Teresa B. Gibson 1, Ph.D.; Tami L. Mark 1 Ph.D., MBA; Kirsten Axelsen 2, MS; Joan A. Mackell 2, Ph.D.; Heidi King 2, MS; Onur Baser 1, Ph.D.; Kimberly A. McGuigan 2, Ph.D., MBA 1 Thomson Medstat, Ann Arbor, MI 2 Pfizer, Inc., New York, NY

2. Copyright 2006 Thomson Medstat 2 THOMSON SCIENTIFIC & HEALTHCARE Introduction HMG-CoA reductase inhibitor (“statin”) therapy is a widely accepted treatment for patients with high cholesterol. Clinical trials report benefits such as reductions in mortality and morbidity from statin therapy (e.g., National Cholesterol Education Program(NCEP) Expert Panel 2002, and Simes et al. 2002). The extent of cardiovascular risk reduction can increase in proportion to the amount of time on statin therapy (Simes et al. 2002)

3. Copyright 2006 Thomson Medstat 3 THOMSON SCIENTIFIC & HEALTHCARE Introduction (continued) Prescription drug copayments have increased as employers and other plan managers attempt to contain prescription drug costs. (Kaiser Family Foundation and the Health Research and Educational Trust 2005) Cost-sharing is likely to continue to rise. Many firms intend to continue to increase cost-sharing in the near future. (Kaiser Family Foundation and the Health Research and Educational Trust 2005; PriceWaterhouseCoopers 2005 ) Higher prescription drug copayments may lead patients with chronic conditions to reduce utilization of maintenance drugs (Bierman and Bell 2004; Gibson et al. 2005) Higher statin copayments are associated with a reduction in compliance for new users of statins. Higher statin copayments and lower levels of statin compliance are also related to lower levels of outcomes (e.g., LDL-C goal attainment and hospitalization). (Goldman et al. 2005, Schultz et al. 2005)

4. Copyright 2006 Thomson Medstat 4 THOMSON SCIENTIFIC & HEALTHCARE Study Aims 1.To estimate the effects of statin copayments on statin adherence for statin users, and, 2.To estimate the effects of statin adherence on expenditures and utilization

5. Copyright 2006 Thomson Medstat 5 THOMSON SCIENTIFIC & HEALTHCARE Data Source MarketScan Commercial Claims and Encounter Database and Medicare Supplemental and Coordination of Benefits Database for services provided from January 1, 2000 through December 31, 2003. –Contains the healthcare experience of individuals with employer- sponsored health care insurance and Medicare supplemental insurance in the United States –Includes enrollment information and inpatient, outpatient and pharmacy claims

6. Copyright 2006 Thomson Medstat 6 THOMSON SCIENTIFIC & HEALTHCARE Inclusion Criteria and Study Sample Inclusion Criteria: –18 years of age or older –Continuously-enrolled from 2000 through 2003 –At least one statin prescription fill January 2001 through June 2001 –No indication of pregnancy during the study time frame Study Sample Construction: –Continuing users: Filled a statin prescription in 2000 –New Users: Filled a statin prescription in Jan-June 2001 and at least one year prior without a statin fill –Each patient was followed July 2001 through December 2003 Continuing Users: n=93,296 patients New Users: n=24,113

7. Copyright 2006 Thomson Medstat 7 THOMSON SCIENTIFIC & HEALTHCARE Measures Adherence to Statin Therapy (July 2001 – December 2002) –Medication Possession Ratio (MPR) calculated by assessing whether statins were on-hand each day, % of days with statins on-hand –Adherent if MPR > 80% Expenditures and Utilization (January - December 2003) –Expenditures – Total (Medical plus prescription drug) Medical Prescription Drug –Utilization (1/0 variables) Physician Office Visit Emergency Room Visit Hospitalization Coronary Heart Disease-related (CHD) Hospitalization

8. Copyright 2006 Thomson Medstat 8 THOMSON SCIENTIFIC & HEALTHCARE Explanatory Variables Patient Cost-Sharing –Statin cost sharing amount (USD $ 2003 per day) –Office Visit cost sharing amount (USD $ 2003 per visit) Sociodemographic - Age, Gender, US Census Region, Urban Area, Household Income and % with College Degree (by ZIP code via Census information) Health Plan Type – (e.g., HMO, PPO, POS, Comprehensive) Type of Provider (prior 12 months) Medication (prior 12 months) - Number of prescriptions, Any use of mail order Severity/Comorbidity (prior 12 months) –Acute Myocardial Infarction, Angioplasty, Coronary Bypass Surgery, Chronic Ischemic Heart Disease (IHD), Coronary Atherosclerosis, Other IHD, Hypertension –Anxiety, Dementia, Depression

9. Copyright 2006 Thomson Medstat 9 THOMSON SCIENTIFIC & HEALTHCARE Multivariate Analysis-Two Stage Residual Inclusion Stage 1: Adherence, Logistic Regression Pr(Adherence i |x) = F(  0 +  1 sociodemographic i +  2 plan i +  3 provider ip +  4 medication ip +  5 severity ip +  6 comorbidity ip +  7 cost-sharing i ) Stage 2: Utilization and Expenditures G(Expenditure i ) = ln(  0 +  1 sociodemographic i +  2 plan i +  3 provider ip +  4 severity ip +  5 comorbidity ip +  6 Adherence +  7 û 1 ) P(Utilization i |x) = F(  0 +  1 sociodemographic i +  2 plan i +  3 provider ip +  4 severity ip +  5 comorbidity ip +  6 Adherence +  7 û 1 ) i is patient, p is a 12 month lag, F is the cumulative logistic function and G is the gamma distribution

10. Copyright 2006 Thomson Medstat 10 THOMSON SCIENTIFIC & HEALTHCARE Selected Characteristics Continuing UsersNew Users Characteristicn=93,296n=24,113 Female (%)44.550.2 Age (y) 64.1  11.258.8  12.6 Insurance Plan Type (%) Comprehensive28.926.2 HMO3.23.9 Capitated POS33.026.3 Non-Capitated POS/EPO6.48.5 Preferred Provider Org.28.835.1 Statin Copayment ($/day) $0.40  0.20 $0.43  0.17

11. Copyright 2006 Thomson Medstat 11 THOMSON SCIENTIFIC & HEALTHCARE Selected Characteristics (continued) Continuing UsersNew Users Characteristic (%) (12 month lag) n=93,296n=24,113 AMI1.61.4 Angina18.917.8 CABG0.90.7 Chronic IHD5.02.9 Coronary Atherosclerosis 24.815.3 Other IHD3.42.5 PCTA0.60.5

12. Copyright 2006 Thomson Medstat 12 THOMSON SCIENTIFIC & HEALTHCARE Measures of Adherence, Utilization and Expenditure Measure n=93,296n=24,113 Adherence/MPR (July 2001-Dec 2002) 0.58  0.490.28  0.45 Utilization and Expenditures (2003) Total Expenditures $6,589.70  7893.24$5,798.63  8485.10 Medical Expenditures $3,513.53  6866.97$3,323.55  7438.78 Prescription Drug Expenditures $3,076.17  2598.15$2,475.08  2767.20 Office Visits 0.93  0.260.90  0.30 ER Visits 0.22  0.410.21  0.41 Hospitalizations 0.14  0.350.12  0.32 CHD-Related Hospitalizations 0.05  0.230.04  0.20

13. Copyright 2006 Thomson Medstat 13 THOMSON SCIENTIFIC & HEALTHCARE Effects of Copayments on Adherence-Continuing Users Predicted Probability of Adherence Selected Effects Adjusted Odds Ratio 95% CI Female (0.863, 0.914) Age, y <=65 (1.025, 1.03) Age, y over 65 (0.982, 0.988) Statin Copayment (0.632, 0.735) Higher copayments are associated with lower levels of adherence All p<.01, n=93,296

14. Copyright 2006 Thomson Medstat 14 THOMSON SCIENTIFIC & HEALTHCARE Effects of Copayments on Adherence-New Users Predicted Probability of Adherence Selected Effects Adjusted Odds Ratio 95% CI Female (0.717, 0.813) Age, y <=65 (1.03, 1.04) Age, y over 65 (0.962, 0.976) Statin Copayment (0.621, 0.918) Higher copayments are associated with lower levels of adherence All p<.01, n=24,113

15. Copyright 2006 Thomson Medstat 15 THOMSON SCIENTIFIC & HEALTHCARE Effects of Adherence on Expenditures Continuing Users ExpendituresCoefficientStandard Errorp-value Total Expenditures0.1790.1170.125 Medical Expenditures -0.2560.1990.197 Prescription Drug Expenditures 0.703***0.0690.000 Higher levels of adherence are associated with higher prescription drug expenditures, lower (nonsignificant) medical expenditures and no change in total medical expenditures. * p<.10,** p<.05, *** p<.01

16. Copyright 2006 Thomson Medstat 16 THOMSON SCIENTIFIC & HEALTHCARE Effects of Adherence on Expenditures New Users ExpendituresCoefficientStandard Errorp-value Total Expenditures-0.0880.1090.423 Medical Expenditures -0.1500.1790.402 Prescription Drug Expenditures 0.0650.0810.426

17. Copyright 2006 Thomson Medstat 17 THOMSON SCIENTIFIC & HEALTHCARE Effects of Adherence on Utilization – Continuing Users CoefficientAdjusted Odds Ratio 95% CI Office Visits0.349(0.688, 2.876) ER Visits-1.514***(0.133, 0.364) Hospitalizations-.566*(0.308, 1.048) CHD-Related Hospitalizations -1.688***(0.072, 0.480) * p<.10,** p<.05, *** p<.01 Higher levels of adherence are associated with a decreased likelihood of ER visits, hospitalizations and CHD-related hospitalizations

18. Copyright 2006 Thomson Medstat 18 THOMSON SCIENTIFIC & HEALTHCARE Effects of Adherence on Utilization – New Users CoefficientAdjusted Odds Ratio 95% CI Office Visits0.927**(1.228, 5.195) ER Visits0.059(0.648, 1.737) Hospitalizations-0.076(0.497, 1.729) CHD-Related Hospitalizations -0.882*(0.158, 1.082) * p<.10,** p<.05, *** p<.01 Higher levels of adherence are associated with an increased likelihood of an office visit, no change in ER visits or hospitalizations and a decreased likelihood of CHD-related hospitalizations

19. Copyright 2006 Thomson Medstat 19 THOMSON SCIENTIFIC & HEALTHCARE Effects of Adherence on Utilization – Continuing Users

20. Copyright 2006 Thomson Medstat 20 THOMSON SCIENTIFIC & HEALTHCARE Effects of Adherence on Utilization – New Users

21. Copyright 2006 Thomson Medstat 21 THOMSON SCIENTIFIC & HEALTHCARE Limitations Administrative Data Continuously-enrolled population with employer-sponsored insurance Selection Sensitivity Analysis

22. Copyright 2006 Thomson Medstat 22 THOMSON SCIENTIFIC & HEALTHCARE Summary and Conclusions In this large cohort of statin users enrolled in employer-sponsored plans, prescription drug copayments are a financial barrier to statin adherence. For continuing/prevalent users of statins, statin adherence is related to higher prescription drug expenditures and a nonsignificant offset in medical expenditures. Total expenditures are not significantly different. For new/incident users of statins, statin adherence is not associated with changes in medical or prescription drug expenditures.

23. Copyright 2006 Thomson Medstat 23 THOMSON SCIENTIFIC & HEALTHCARE Summary and Conclusions For continuing users of statins, lower statin copayments are associated with higher levels of statin adherence. Total costs may not change, but fewer negative events (ER visits, hospitalizations and CHD-related hospitalizations) occur. Reducing patient cost-sharing for a maintenance drug regime may be an effective intervention.