Association between Medication Adherence and Healthcare ...

10/28/2019

1

1

Association between Medication Adherence and Healthcare Costs among Patients Receiving the Low‐Income Subsidy

Junling Wang, PhD

Professor, Department of Clinical Pharmacy & Translational Science University of Tennessee College of Pharmacy

Presenter Disclosures

(1) The following personal financial relationships with commercial interests relevant to this presentation existed during the past 12 months:

<Junling Wang, PhD>

< This study was sponsored by the Pharmaceutical Research and Manufacturers of America as a grant to Drs. Junling Wang and Kenneth C. Hohmeier.>

Presenter Disclosures

(2) My presentation will include discussion of “off‐label” use of the following:

<Junling Wang, PhD>

<None.>

10/28/2019

2

Department of Clinical Pharmacy and Translational Science

Co‐Authors

University of Tennessee College of Pharmacy Yanru Qiao, MS

Kenneth C. Hohmeier, PharmDEdward T. Chiyaka, PhD

Pharmaceutical Research & Manufacturers of AmericaSamantha T. Dougherty, PhD

4


5

• Medications are one of the most cost‐effective interventions used to improve healthcare outcomes.

• Medication adherence helps to bring about treatment benefits for medications, reduce complications from chronic diseases, and lower medical costs.

• Medication non‐adherence could mitigate the effectiveness of medication therapy

– 10% of all hospitalizations, and along with other drug‐related morbidity and mortality, costing the healthcare system $100‐$290 billion per year.

Background


Background

• Adherence rates vary widely across population categories and disease states.

• Factors associated with adherence include:

–Patient socio‐demographics & health beliefs

–Medication‐related factors

–Healthcare system‐related factors

• Patients of lower socioeconomic backgrounds suffer most acutely from barriers that prevent adherence.

6

10/28/2019

3


Background

7

• Low‐income subsidy (LIS)

– Established by the Medicare Modernization Act, part of Medicare prescription drug benefit (Part D)

– Limited assets and income below 150% of federal poverty level

• In 2018, more than 43 million Medicare beneficiaries were enrolled in Medicare Part D, and 28% received the LIS.

• LIS enrollees

–More likely to be non‐White, and less educated.

– Higher overall prevalence of mental and physical health conditions.


Background• Among LIS recipients with multiple chronic conditions, the effect of patients being adherent to all recommended medications is not clear.

• Proportion of days covered (PDC) – measures proportion of days a patient is likely to have taken their medication.

• PDC≥80% indicates that the patient is adherent to medication.

• Due to the heterogeneity of medication effects and patient characteristics, such uniform dichotomies may fail to fully capture the optimum classification of patient adherence level.

8


Study Objective

9

• Explore the effects of medication adherence on healthcare costs among LIS recipients with:

‒ Diabetes

‒ Hypertension

‒ Heart failure

10/28/2019

4


Methods

10

• Retrospective analysis

–Medicare administrative data from 2012‐2013

– Linked to Area Health Resources Files (AHRF)


Conceptual Framework: Gelberg‐Andersen Behavioral Model for Vulnerable Populations

Groups Variables

Predisposing Factors

Race and ethnicity, age, gender, % non‐white population, % married‐couple families, per capita income, % people in poverty, % various educational achievements, % eligible for Medicaid, % unemployed, % without health insurance

Enabling Factors Metropolitan statistical area, census regions, health professional shortage area

Need Factors Charlson Comorbidity Index, risk adjustment summary score


Methods

12

• Study Population

– ≥ 65 years old

– Alive during the study

– Continuous Parts A/B/D coverage (to eliminate any coverage gap)

– Full or partial LIS

• Patient cohorts

– 3 cohorts of patients with only 1 disease of interest

– 3 cohorts with various combinations of 2 out of 3 diseases

– 1 cohort with all 3 diseases

10/28/2019

5


Methods

13

• Monthly PDC was used to measure patient adherence

• Based on the cutoff points used by Star Ratings to assign levels of stars to health plans.

• Cost categories (monthly costs): Medicare medical costs (Parts A and B) and total Medicare costs (Parts A, B, D).

Patients with 1 chronic disease Patients with 2 or 3 diseases

8 PDC categories: <25%, 25%‐<50%, 50%‐<75%, 75%‐<80%, 80%‐<85%, 85%‐<90%, 90%‐<95%, ≥95%

PDC≥80% for medications for each disease


Methods

14

• Test for differences

– Cost difference between each individual adherence category and lowest adherence category Potential cost savings

– Tukey’s test was used to compare costs across adherence categories following analysis of variance.

• Multivariate analysis on relationship between adherence and cost

– Linear model with log link and gamma distribution to control for individual and community characteristics.


Variable Diabetes Hypertension Heart Failure

Number (% of study sample) 49,157 (8.5) 237,856 (40.9) 7,914 (1.4)

Age 76.5 (7.4) 77.8 (8.1) 81.6 (9.0)

Male (number & %) 15,885 (32.3) 63,748 (26.8) 2,547 (32.2)

Race/Ethnicity (number & %)

Non‐Hispanic White 26,989 (54.9) 141,610 (59.5) 5,829 (73.7)

Non‐Hispanic Black 6,689 (13.6) 39,871 (16.8) 886 (11.2)

Hispanic 9,485 (19.3) 31,809 (13.4) 694 (8.8)

% of Non‐White Populationa 27.6 (18.4) 28.72 (17.9) 25.59 (17.8)

% of Married Couple Familiesa 75.2 (7.2) 74.67 (7.2) 75.80 (7.1)

% Eligible for Medicaida 24.1 (9.4) 23.40 (9.0) 23.00 (9.0)

% Unemployed Populationa 8.1 (2.5) 8.0 (2.2) 7.9 (2.2)

% Without Health Insurancea 15.5 (5.2) 15.3 (5.0) 14.9 (4.8)

Sociodemographic characteristics of study cohorts (mean and standard deviation; N=581,145)

a County-level characteristics.

10/28/2019

6


a County‐level characteristics.

Sociodemographic characteristics of study cohorts (mean and standard

deviation)Variable Diabetes Hypertension Heart Failure

Metropolitan Statistical Area (number & %) 35,494 (72.2) 182,402 (76.7) 5,489 (69.4)

Health Professional Shortage Area (number & %) 45,545 (92.7) 216,745 (91.1) 7,208 (91.1)

Region (number & %)a

Northeast 9,884 (20.1) 47,692 (20.1) 1,608 (20.3)

Midwest 9,566 (19.5) 41,673 (17.5) 1,672 (21.1)

South 17,321 (35.2) 104,738 (44.0) 3,000 (37.9)

West 12,300 (25.0) 43,439 (18.3) 1,625 (20.5)

Other 86 (0.2) 314 (0.1) 9 (0.1)

Charlson Comorbidity Index 2.9 (2.1) 1.7 (1.9) 3.1 (1.9)

Risk Adjustment Summary Score 1.1 (0.7) 1.1 (0.7) 1.7 (0.8)


Patients with one chronic disease

17

3.6%

10.8%

16.2%

5.4%

8.4%

11.5%

17.9%

26.2%

2.7%

7.1%

12.6%

4.9%

7.9%

12.0%

19.6%

33.2%

4.6%

9.3%

14.6%

4.9%

7.3%

11.2%

18.2%

29.8%

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

PDC<25% 25%≤PDC<50% 50%≤PDC<75% 75%≤PDC<80% 80%≤PDC<85% 85%≤PDC<90% 90%≤PDC<95% PDC≥95%

Proportion

Proportion of Days Covered (PDC)

Diabetes Hypertension Heart Failure

Although most patients had PDC≥80%, over 25% had PDC<80%

Diabetes Hypertension Heart Failure

36.0% 27.3% 33.5%


18

749694 686

622593 583

488a448

876

791831

769733 743

677 670

0

100

200

300

400

500

600

700

800

900


Average monthly costs ($)

Proportion of days covered (PDC)

Medicare medical costs Total Medicare costs

a P<0.05 for comparison between a category and its neighbor to the immediate left. Patients with higher adherence had lower costs.

Healthcare costs across adherence categories for patients with diabetes

10/28/2019

7


19

0

55 63

127

156a 166a

261a

301a

0

85

45

107

143a 133a

199a 206a

0

50

100

150

200

250

300


Average monthly costs ($)

Proportion of days covered (PDC)


a P<0.05 for comparison between a category and the lowest adherence category. Total Medicare spending for the most adherent patients was $206 (23.5%) lower than for patients with the lowest adherence.

Difference in costs between a category and the lowest adherence category for patients with diabetes


Adherence among patients with diabetes & hypertension

15.3%18.7%

6.7%

59.2%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

PDC<80% for both diabetes& hypertension medication

PDC≥80% for hypertension medication only

PDC≥80% for diabetes medication only

PDC≥80% for both diabetes & hypertension medication

Proportion

About 15% of the patients were not adherent to both diabetes and hypertension medication.


Healthcare costs across adherence categories (patients with diabetes and hypertension)

aP<0.05 for comparison between a category and its neighbor to the immediate left. Patients adherent to medications for both diseases had lower Medicare medical cost and total costs than those adherent to medications for only one disease.

942

846a792a

624a

1,0701,035 1,005

865a

0

200

400

600

800

1000

1200

PDC<80% for both diabetes &hypertension medication




Average M

onthly cost ($)


10/28/2019

8


0

96a

150a

318a

0

3565

205a

0

50

100

150

200

250

300

PDC<80% for both diabetes &hypertension medication




Average M

onthly cost ($)


a P<0.05 for comparison between a category and the lowest adherence category. Total Medicare spending for the most adherent patients was $205 (19.2%) lower than patients with the lowest adherence.

Difference in costs between a category and the lowest adherence category (patients with diabetes & hypertension)


23

14.4%

8.4%

23.5%

53.7%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

PDC<80% for medicationsfor all three chronic

conditions

PDC≥80% for any one chronic condition

PDC≥80% for medications for any two chronic

conditions

PDC≥80% for medications for all chronic conditions

Proportion

Almost half of the patients with three diseases were non‐adherent to medication for all three diseases (46.3%).

Adherence to medications for patients with three conditions


24

2,136

1,827a

1,601a

1,168a

2,3282,138a

1,859a

1,524a

0

500

1,000

1,500

2,000

2,500


conditions



conditions


Average M

onthly cost ($)


Healthcare costs across adherence categories

a P<0.05 for comparison between a category and its neighbor to the immediate left. Patients non‐adherent to any medications had total costs 1.5 times that of patients adherent to all medications ($2,328 vs. $1,524; P<0.0001).

10/28/2019

9


0

309a

535a

968a

0

190a

469a

804a

‐10

90

190

290

390

490

590

690

790

890

990


conditions



conditions


Average M

onthly cost ($)


a P<0.05 for comparison between a category and the lowest adherence category.

Difference in costs between a category and the lowest adherence category


Medical Costs Total Costs

Ratio 95% Confidence Interval Ratio 95% Confidence Interval

Patients with Diabetes

25%≤PDC<50% 1.02 0.91 – 1.15 1.04 0.94 – 1.14

50%≤PDC<75% 1.02 0.91 – 1.15 1.06 0.97 – 1.17

75%≤PDC<80% 0.95 0.83 – 1.09 1.02 0.91 – 1.14

80%≤PDC<85% 0.98 0.86 – 1.11 1.05 0.95 – 1.16

85%≤PDC<90% 0.98 0.87 – 1.11 1.07 0.97 – 1.18

90%≤PDC<95% 0.80 0.71 – 0.90 0.95 0.86 – 1.04

PDC≥95% 0.75 0.61 – 0.84 0.96 0.88 – 1.05

Patients with Heart Failure

25%≤PDC<50% 0.87 0.71 – 1.07 0.89 0.74 – 1.07

50%≤PDC<75% 0.73 0.60 – 0.89 0.76 0.64 – 0.91

80%≤PDC<85% 0.69 0.55 – 0.85 0.75 0.62 – 0.91

85%≤PDC<90% 0.58 0.47 – 0.71 0.65 0.54 – 0.78

90%≤PDC<95% 0.50 0.41 – 0.600.57 0.49 – 0.68

PDC≥95% 0.43 0.36 – 0.510.52 0.45 – 0.62

Effects of medication adherence on healthcare costs among Medicare beneficiaries in adjusted analysis

(PDC<25% as reference)


Medical Costs Total Costs

Ratio 95% Confidence Interval Ratio 95% Confidence

Interval

Patients with Diabetes and Hypertension

PDC<80% for Medications for Both Diseases ‐ ‐ ‐ ‐

PDC≥80% for Hypertension Medications Only 0.93 0.90 – 0.96 1.01 0.98 – 1.03

PDC≥80% for Diabetes Medications Only 0.91 0.87 – 0.95 1.01 0.97 – 1.05

PDC≥80% for Medications for Both Diseases 0.77 0.75 – 0.79 0.92 0.90 – 0.94

Patients with Diabetes, Hypertension and Heart Failure

PDC<80% for All Medications ‐ ‐ ‐ ‐

PDC≥80% for Medications for One Disease 0.88 0.82 – 0.95 0.95 0.89 – 1.01

PDC≥80% for Medications for Two Diseases 0.83 0.79 – 0.88 0.88 0.83 – 0.92

PDC≥80% for All Three Diseases 0.67 0.64 – 0.71 0.78 0.75 – 0.82

27

Effects of medication adherence on healthcare costs among Medicare beneficiaries based on adjusted regression model

10/28/2019

10


Results

• Most adherent patients with diabetes & heart failure had 25% & 57%, respectively, lower Medicare medical costs compared with the lowest adherent patients.

• Patients adherent to medications for both diseases had total Medicare costs 23% lower than those adherent to medications for neither disease.

• Medicare medical costs for patients adherent to medications for all three diseases were 33% lower compared to patients non‐adherent to medications for any of the three diseases.

28


Study Limitations

29

• Additional sociodemographic/clinical information not available.

• Medication adherence may be over‐ or underestimated using claims.

• One cannot draw causal conclusions regarding the relationship between adherence and cost savings because this is an observational study.


Conclusion

30

• A large portion of the LIS population are not adherent to prescribed medications.

• Higher adherence is associated with significant economic benefits.

• Cost savings can be achieved with even moderate increase in adherence.

• “Super‐adherent” patients (PDC≥95%) may incur the highest cost savings.

10/28/2019

11


Conclusion

31

• Prime areas for future research:

–New initiatives to target incremental improvements from patient’s adherence baseline.

– Roles of other interventions in improving medication adherence among the LIS population, particularly among those with multiple chronic conditions.

– The causal relationship between adherence and healthcare costs.

• Strategies to improve adherence in this population are promising for controlling healthcare costs.


Acknowledgements

32

• This study was supported by Pharmaceutical Research & Manufacturers of America.

• We would like to acknowledge the assistance from Jenny Lee, Laura Meyer, Jason Zeng, Michael Tran, Anoop Pravin Kotian, David Q. Brannon II, Damien Stevenson, and Lorraine Todor, all PharmD students at the University of Tennessee College of Pharmacy.


References

33

• Congressional Budget Office. Offsetting effects of prescription drug use on Medicare’s spending for medical services. Available at: https://www.cbo.gov/publication/43741.

• Goldman L, Epstein AM. Improving adherence ‐money isn't the only thing. N Engl J Med 2011;365:2131‐3.

• Research Data Assistance Center. Data File Search. Available at: http://www.resdac.org/cms‐data.

• Health Resources and Services Administration (HRSA). Area Health Resources Files. Available at: https://data.hrsa.gov/topics/health‐workforce/ahrf.

• Gelberg L, Andersen RM, Leake BD. The behavioral model for vulnerable populations: application to medical care use and outcomes for homeless people. Health Serv Res 2000;34(6):1273‐302.

• Pharmacy Quality Alliance (PQA). Available at: https://www.pqaalliance.org/.

• Centers for Medicare & Medicaid Services. Part C and D Performance Data. Available at: https://www.cms.gov/medicare/prescription‐drug‐coverage/prescriptiondrugcovgenin/performancedata.html.

Association between Medication Adherence and Healthcare ...

Documents

Transcript of Association between Medication Adherence and Healthcare ...