1. Self-reported Effects of Prescription Drug Cost-Sharing: Decreased Adherence and Increased Financial Burden Mary Reed, MPH 1 Vicki Fung 1 Richard Brand, PhD 2 Bruce Fireman, MA 1 Joseph P. Newhouse, PhD 3 Joseph V. Selby, MD, MPH 1 John Hsu, MD, MBA, MSCE 1 1 Kaiser Permanente - Division of Research 2 University of California, San Francisco 3 Harvard University Academy Health Annual Research MeetingJune 7, 2004

2. Introduction ► Drug expenditures are increasing each year in the US ► Patients are paying for an increasing share for their prescription drugs: cost-sharing ► Cost-sharing effects may be influenced by patient knowledge ► Limited information about: –Patient knowledge about their prescription drug cost-sharing –How patients behave when faced with this cost-sharing

3. Purpose ► To examine patient knowledge of their prescription drug cost-sharing level: –Any prescription drug cost-sharing? –Structure of prescription drug cost-sharing (multi-tier copayments and benefit caps)? –Amount of drug cost-sharing (copayment amounts and benefit cap amounts)? ► To examine self-reported patient behavioral responses to prescription drug cost-sharing: –Do patients report taking less than the prescribed amount of a drug (adherence)? –Do patients report having to struggle to pay for their prescription drugs (burden)?

4. Methods – Design/Population/Sample ► Cross-sectional Design: Telephone interviews in 2003 ► Population: –Active members in a large, prepaid integrated delivery system (IDS) –Age 18 years or more –English-speaking –Commercial or Medicare insurance ► Stratified random sample: –A: General Population (30%) –B: Members over age 65 (70%) ► Population is a subset of a larger study on clinical and economic effects of cost-sharing

5. Questionnaire Measures - Adherence ► “Because of the amount you had to pay, have you”: –“taken less than the prescribed amount to make it last longer” –“not filled a prescription for a new medication” –“stopped refilling a prescription”

6. Questionnaire Measures - Burden ► “Because of the amount you had to pay, have you”: –“switched to a cheaper medication (e.g. generic)” –“gotten free medication samples from a doctor” –“gone to a non-Kaiser pharmacy instead” –“gotten help paying for medications through an [assistance] program” –“borrowed $ to pay for medications” –“gone without some necessity such as food, rent, heat, or other basics” –“bought a prescription medication in another country” –“bought a medication from an internet pharmacy”

7. Methods – Analysis ► Models: Multivariate logistic regression ► Predictor Measure: –Perceived/Actual Drug cost-sharing: Generic Copayment ($), Brand-Generic Copayment ($), Any Benefit Cap ► Outcome Measures –Decreased Adherence –Financial Burden ► Covariates –Socio-demographic: age, gender, race/ethnicity, marital status, household income, educational level –Clinical: self-reported health status, self-reported number of prescription drugs in previous 12 months, comorbidity (DxCG)

8. Figure 1. Study Design: Interview Participation n=932 (72%) *Ineligible = deceased, incapable of phone interview (e.g. hearing difficulties, dementia), non-English speaker, unable to be contacted KPNC Adult Population: Commercial and Medicare Population Interviewed n=254 (70%) Interviewed n=678 (73%) Refused n=251 (27%) Ineligible* n=261 Age 65+ (70%) n=1190 Overall Population (30%) n=510 Members Randomly Selected and Contacted for Interview n=1700 [2 Strata] Refused n=109 (30%) Ineligible* n=147

9. Table 1. Participant Characteristics CharacteristicTotal (n=932) % Sample A: Overall Pop. (n=254) % Sample B: Age 65+ (n=678) % Age 65+77.714.2100.0 Female Gender55.850.558.8 Non-white Race26.235.522.7 Education: less than College Graduate67.259.069.7 Married63.971.661.6 Household Income: < $35,00043.218.851.3 Self Reported Health: Excellent or Very Good44.453.741.6 Persons with Any Prescription Meds w/in 12 mos.90.982.193.5 Persons with Any ED Visits within 12 mos.23.821.724.7

10. Table 2. Knowledge of Drug Cost-Sharing Cost Sharing Type Any Cost-Sharing Amount of Cost Sharing Self- Report KP Actual Correctly Reported Under- estimate Exactly Correct Over- estimate %% % % Generic Copay92.982.384.98.070.022.0 Brand Name Tiered Copay61.274.473.833.350.516.2 Benefit Cap31.233.485.65.059.435.6

11. Figure 2. Self-Reported Behavioral Response to Cost-sharing: Decreased Adherence

12. Figure 3. Self-Reported Behavioral Responses to Cost-sharing: Increased Burden

13. Table 3. Behavioral Response to Cost-sharing: Decreased Adherence Multivariate Logistic Regression Models Adjusted for Comorbidity *p=<0.10, †p=<0.05, ‡p=<0.01, CI= Confidence Interval CharacteristicSelf-Reported Cost-Sharing Actual Cost- Sharing OR95% CIOR95%CI Drug Cost-Sharing: Generic Copay ($) 1.040.99, 1.100.960.81, 1.14 Brand – Generic Copay ($) 1.01 † 1.00, 1.031.040.97, 1.11 Any Benefit Cap 2.37 ‡ 1.26, 4.471.760.74, 4.19 Age 65+ 0.570.23, 1.400.39 † 0.16, 0.92 Female Gender 1.730.89, 3.361.540.84, 2.83 Non-White Race 1.130.57, 2.251.350.73, 2.49 Education: less than College Graduate 0.54*0.28, 1.040.44 ‡ 0.24, 0.81 Married 1.420.75, 2.721.430.79, 2.61 Household Income < $35,000 3.08 ‡ 1.50, 6.353.03 ‡ 1.54, 5.98 Health Excellent or Very Good 0.800.41, 1.560.900.49, 1.65 Number of RX’s used in 12 mos.: 0,1,2-4,5+1.76 † 1.04, 2.991.95 ‡ 1.20, 3.18

14. Table 4. Behavioral Response to Cost-sharing: Increased Burden Multivariate Logistic Regression CharacteristicSelf-Reported Cost-Sharing Actual Cost- Sharing OR95% CIOR95% CI Drug Cost-Sharing: Generic Copay ($) 1.04*0.99, 1.090.960.81, 1.14 Brand – Generic Copay ($) 1.01 † 1.00, 1.031.040.97, 1.11 Any Benefit Cap 1.94 † 1.16, 3.251.760.74, 4.19 Age 65+ 0.42 † 0.20, 0.860.39 † 0.16, 0.92 Female Gender 1.96 † 1.15, 3.351.540.84, 2.83 Non-White Race 1.300.76, 2.241.350.73, 2.49 Education: less than College Graduate 1.270.73, 2.220.44 ‡ 0.24, 0.81 Married 1.59*0.93, 2.721.430.79, 2.61 Household Income < $35,000 3.07 ‡ 1.73, 5.473.03 ‡ 1.54, 5.98 Health Excellent or Very Good 0.680.40, 1.170.900.49, 1.65 Number of RX’s used in 12 mos.: 0,1,2-4,5+ 1.46*0.97, 2.191.95 ‡ 1.20, 3.18 Models Adjusted for Comorbidity *p=<0.10, †p=<0.05, ‡p=<0.01, CI= Confidence Interval

15. Limitations ► Single IDS with a range of delivery options ► English-speakers only ► Modest levels of cost-sharing ► Self-reports of behavioral responses ► No measure of clinical impact of behavioral responses

16. Conclusions ► Patients appeared to have general knowledge of their prescription drug cost-sharing, but limited knowledge about the amounts ► Nearly one in four patients changed their behavior in response to their perceived level of prescription drug cost- sharing –Over one in ten patients did not take their drugs as prescribed because of their perceived level of drug cost- sharing –Nearly one in five patients reported an increased burden in paying for their prescription medications

17. Implications ► The impact of drug cost-sharing on behavior may be attenuated due to limited knowledge of actual cost-sharing amounts ► Persons with more drug use or lower income may be more likely to change their behavior in response to drug cost- sharing ► Additional research is needed on the clinical and economic ramifications of prescription drug cost-sharing