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Gender Differences in Prescribing Drugs

Potentially Harmful to Elderly in Managed Care

Lok Wong, MHS; Russell Mardon, PhD; Phil Renner, MBA - National Committee for Quality Assurance; Arlene Bierman, MD, MS - University of Toronto

Academy Health June 2005Assessing and Improving Quality of Care

by Gender

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AcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements

NCQA Geriatric Measurement Advisory Panel

Medication Management Technical SubgroupArlene Bierman, MD, MS ;

Emerald Foster, Pharm.D., CGP; Jerry Gurwitz, MD;

Joseph T. Hanlon, Pharm.D. ; Mark E. Lehman, Pharm.D. FASCP;

Edward Westrick, MD, PhD

This study was supported by the Centers for Medicaid and Medicare Services (CMS) under a

HEDIS contract

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Gender - Research Objective Gender - Research Objective Gender - Research Objective Gender - Research Objective

• Population-based studies found older women more likely to receive potentially inappropriate drugs than older men.

• Question: Do gender differences in drug prescribing patterns exist within Medicare managed care plans?

• Question: Are elderly women enrollees more likely than elderly men to receive drugs potentially harmful to the elderly?

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Consensus on Harmful DrugsConsensus on Harmful DrugsConsensus on Harmful DrugsConsensus on Harmful Drugs

• Consensus on drugs generally to be avoided in the elderly due to potential harms regardless of underlying health condition, age or gender

• Zahn (33 drugs/classes) criteria (2001):– Never appropriate– Rarely appropriate– Sometimes indicated

• Beers (48 drugs/classes) updated criteria (2003):– High severity– Low severity

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Gender - Study PopulationGender - Study PopulationGender - Study PopulationGender - Study Population

• Over 824,000 Medicare enrollees in 2002 and over 803,000 in 2003

• Ages 65 and older • 63% female • 9 health plans across the United States• Average number of enrollees per plan

from 7,500 to 187,000.• Continuously enrolled during the year• Pharmacy benefits

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Gender - Study DesignGender - Study DesignGender - Study DesignGender - Study Design

• Retrospective pharmacy claims data analysis

• Percentages of Medicare elderly 65+ enrolled

throughout the year with pharmacy benefits who

received:

1. at least one drug to be avoided in the elderly

2. at least two drugs from different therapeutic classes to be

avoided in the elderly

Rates calculated by plan, age, gender and

across the total study population.

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Principal FindingsPrincipal FindingsPrincipal FindingsPrincipal Findings

• Nearly a million elderly enrollees received more than 3 million prescriptions of drugs potentially harmful in the elderly

• Average 3-6 prescriptions per member• 20% of enrollees received at least 1 drug

never or rarely appropriate in the elderly~165,000 enrollees received 500,000 prescriptions

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Gender-specific FindingsGender-specific FindingsGender-specific FindingsGender-specific Findings• Women are more likely than men to receive high-

risk drugs (Zahn)– At least 1 drug never or rarely appropriate (24%

vs. 16%):• Never appropriate: (5.4% vs. 3.2%) • Rarely appropriate: (18.8% vs. 12.5%)

– At least 2 different drugs never appropriate or rarely appropriate (4% vs. 2%)

• Older enrollees (85 +) slightly less likely than 65-74 to receive two or more drugs (2.8% vs 3.2%)

• Differences are statistically significant. • Similar results and patterns were found in 2003 data.

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Drugs to be Avoided – Drugs to be Avoided – never or rarely appropriatenever or rarely appropriate

Drugs to be Avoided – Drugs to be Avoided – never or rarely appropriatenever or rarely appropriate

Year Min %

Average %

Max %

Male %

Female %

*Dif %Female % - Male %

2002 13.2 20.5 29.9 15.7 24.2 +8.5

2003 12.3 20.1 29.2 15.1 23.8 +8.7

Year Min %

Average %

Max %

Male %

Female % *Dif %Female % - Male %

2002 1.5 3.2 5.1 1.9 4.1 +2.2

2003 1.1 3.1 4.3 1.8 4 +2.2

At least 2 drugs to be avoidedAt least 2 drugs to be avoidedAt least 2 drugs to be avoidedAt least 2 drugs to be avoided

At least 1 drug to be avoidedAt least 1 drug to be avoided% Medicare enrollees prescribed drugs to be avoided

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HEDIS Measure: Drugs to be AvoidedHEDIS Measure: Drugs to be AvoidedHEDIS Measure: Drugs to be AvoidedHEDIS Measure: Drugs to be Avoided

• NCQA expert panel added drugs from the updated Beers list to final HEDIS measure

• Total 59 drugs in 18 therapeutic classes selected• Includes drugs used mostly by women:

– Estrogen (note: data pre-WHI study)– Anti-anxiety drugs– Narcotic pain-relievers

HEDIS 2006 Measure Definition• Percentages of Medicare enrollees 65+ with:

– at least one drug to be avoided in the elderly

– at least two different drugs to be avoided in the elderly

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Harmful Prescriptions: Women vs. MenHarmful Prescriptions: Women vs. MenHarmful Prescriptions: Women vs. MenHarmful Prescriptions: Women vs. Men• Estrogen (18% vs. 0.1%)• Anti-anxiety, sedative hypnotics and benzos (12.5% vs 6%)• Narcotic analgesics and propoxyphene (5.3% vs. 2.2%)• Skeletal muscle relaxants (2.9% vs. 1.4%)• Antihistamines (2.6% vs. 1.3%)• Nitrofurantoin (1.8% vs. 0.3%)• GI antispasmodic – dicylcomine, propantheline (0.8% vs. 0.2%)• Belladonna Alkaloids (0.65% vs. 0.23%)• Thyroid hormones (0.68% vs. 0.1%)• Vasodilators - dipyridamole (0.36% vs. 0.28%)• Barbiturates (0.22% vs. 0.15%)• Antiemitics (0.25% vs. 0.13%)• Oral hypoglycemics – chlorpropamide (0.07% vs. 0.07%)

– Underlined are additional Beers drugs added to the measure

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Prescribing Rates in Women vs. MenPrescribing Rates in Women vs. MenPrescribing Rates in Women vs. MenPrescribing Rates in Women vs. Men

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

Any Zhan/BeersDrugNever

Rarely

Never + Rarely

Sometimes

Additional Beers

Female Male

65-74 Years

Female Male

75-84 Years

Female Male

85+ Years

% of Medicare Enrollees prescribed at least 1 High-Risk Drug

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ConclusionsConclusionsConclusionsConclusions• Elderly women in Medicare managed care more likely

than elderly men to receive drugs harmful to the elderly

• Overall high rates of harmful prescribing are of concern given the majority of Medicare enrollees are women

• High-risk drugs may pose more harms in women due to smaller body size and physiological differences

• Measures chronological age: proxy for frailty• Need to understand if differential disease burden by

gender, patient or provider characteristics explain gender differences in rates of harmful drugs

• Need to develop drug-risk classification systems to determine if there are gender differences in exposure to harms from drugs, i.e. impact of including estrogen

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Implications for Policy and PracticeImplications for Policy and PracticeImplications for Policy and PracticeImplications for Policy and Practice

• Gender-focused interventions are needed to reduce harms from prescribing harmful drugs and improve quality of medication management

• Medicare policies (i.e. drug benefits and formularies) need to account for gender differences in exposure to drug harms by Medicare beneficiaries

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ReferencesReferencesReferencesReferences1. Fick DM, Cooper JW, Wade WE, Waller JL, Maclean JR, Beers MH. Updating

the Beers criteria for potentially inappropriate medication use in older adults. Arch Intern Med. 2003; 163: 2716-2724.

2. Beers MH. Explicit criteria for determining potentially inappropriate medication use by the elderly. Arch Intern Med 1997; 157: 1531-1536.

3. Zhan C, Sangl J, Bierman AS, Miller MR, Friedman B, Wickizer SW, Meyer GS. 2001. Potentially inappropriate medication use in the community-dwelling elderly. JAMA 286(22): 2823-2868.

4. Women’s Health Initiative: Rossouw JE, et al; Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women's Health Initiative randomized controlled trial. JAMA. 2002 Jul 17;288(3):321-33

5. Kaufman MB, Brodin KA, Sarafian A, Effect of Prescriber Education on the Use of Medications Contraindicated in Older Adults in a Managed Medicare Population. J Manag Care Pharm. 2005 April/May;11(3):211-219.

6. Steven R. Simon, MD, MPH, K. Arnold Chan, MD, ScD, Stephen B. Soumerai, ScD, Anita K. Wagner, PharmD, DPH, Susan E. Andrade, ScD, Adrianne C. Feldstein, MD, MS, Jennifer Elston Lafata, PhD, Robert L. Davis, MD, MPH, Jerry H. Gurwitz, MD, Potentially Inappropriate Medication Use by Elderly Persons in U.S. Health Maintenance Organizations, 2000-200, Journal of the American Geriatrics Society, 2005, Volume 53, Issue 2, page 227-232

6. Ensrud KE et al, Central Nervous System – Active medications and risk for falls in older women, JAGS 50:1629-1637, 2002

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Contact InformationContact InformationContact InformationContact Information

Corresponding author:

Lok Wong, MHS

Senior Health Care Analyst

Quality Measurement

National Committee for Quality Assurance

2000 L Street, NW, Suite 500

Washington D.C. 20036

wong@ncqa.org

Tel: 202 – 955 – 1784