Gender Differences in Prescribing Drugs Potentially Harmful to Elderly in Managed Care

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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 2005 Assessing and
Improving Quality of Care by Gender
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Acknowledgements

• NCQA Geriatric Measurement Advisory Panel
• Medication Management Technical Subgroup
• Arlene 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

• 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 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 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 Design

• Retrospective pharmacy claims data analysis
• Percentages of Medicare elderly 65 enrolled
  throughout the year with pharmacy benefits who
  received
• at least one drug to be avoided in the elderly
• 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 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 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 never or rarely appropriate
Medicare enrollees prescribed drugs to be
avoided
At least 1 drug to be avoided
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
At least 2 drugs to be avoided
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
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HEDIS 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. 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. Men
of Medicare Enrollees prescribed at least 1
High-Risk Drug
Female Male 65-74 Years
Female Male 75-84 Years
Female Male 85 Years
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Conclusions

• 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 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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References

• 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.
• Beers MH. Explicit criteria for determining
  potentially inappropriate medication use by the
  elderly. Arch Intern Med 1997 157 1531-1536.
• 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.
• Womens 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 17288(3)321-33
• 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/May11(3)211-219.
• 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
• Ensrud KE et al, Central Nervous System Active
  medications and risk for falls in older women,
  JAGS 501629-1637, 2002

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Contact 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_at_ncqa.org
• Tel [phone]