Prevalence and Patterns of Medication Use Among Older Adults in the US: Findings from a National Population- based Study Dima Qato, PharmD, MPH G. Caleb Alexander MD, MS Rena M. Conti, PhD Michael Johnson, BA Phil Schumm, MA Stacy Tessler Lindau, MD, MAPP The University of Chicago, Chicago, Illinois Academy Health Annual Research Meeting, June 2008

Objectives Determine recent prevalence and patterns of medication use in the elderly Determine recent prevalence and patterns of medication use in the elderly Assess medication-related quality of care Assess medication-related quality of care

Background 92% of elderly have a prescription drug expense. 92% of elderly have a prescription drug expense. 13% use Rxs concurrently with alternative medicines 13% use Rxs concurrently with alternative medicines 21% use 5 or more Rx medications 21% use 5 or more Rx medications Elderly increased risk for Adverse Drug Events (ADE). Elderly increased risk for Adverse Drug Events (ADE). ADE-related hospitalizations/ER visits most commonly due to GI bleeding ADE-related hospitalizations/ER visits most commonly due to GI bleeding Increase in Medicare spending on Rx drugs (2% in 2005 to 18% in 2006) Increase in Medicare spending on Rx drugs (2% in 2005 to 18% in 2006) Kaiser Family Foundation, 2007; Catlin, et al, 2008; Kaufman et al 2002; Gardiner et al 2006; Becker et al, 2007; Budnitz et al, 2007

Limitations of available medication data sources Claims/administrative data Claims/administrative data – Only patients with access to health care – Only prescribed/dispensed medications – Do not measure actual drug use (ingestion) Do not focus on elderly (aggregate adults 65 and older) Do not focus on elderly (aggregate adults 65 and older) Do not measure use of all types of medications. Do not measure use of all types of medications. Outdated (do not account for new medications that enter market) Outdated (do not account for new medications that enter market)

Study Methods Data: National, Social life, Health, and Aging Project (NSHAP)- Wave I ( ) Data: National, Social life, Health, and Aging Project (NSHAP)- Wave I ( ) In-home interview of 3,005 community-residing adults ages In-home interview of 3,005 community-residing adults ages Nationally-representative population-based probability sample; minority over-sampling; response rate=75.5% Nationally-representative population-based probability sample; minority over-sampling; response rate=75.5% Weighted-estimates Weighted-estimates Universe: Directly-observed Medication log Universe: Directly-observed Medication log medications currently used on a regular schedule, like every day or every week. Including prescription, OTC, vitamins, herbals and alternative medicines. medications currently used on a regular schedule, like every day or every week. Including prescription, OTC, vitamins, herbals and alternative medicines. Drug name matching rate=97% Drug name matching rate=97% Micromedex Interaction software Micromedex Interaction software

Prevalence of use Measures Prescription medication use: use of at least one medication available only with a prescription. Over-the-counter use: Use of non-prescription medication that is not a dietary supplement. Dietary supplement use: use of a nutritional product or alternative medicine. Patterns of use Measures Poly-pharmacy: use of 5+, 10+ Rx medications Concurrent use: use of a Rx medication concurrently with a non-Rx medication Quality of Care Measure Major medication interaction: a drug-drug interaction of potentially Major severity as defined by Micromedex® among users of the 20 most common Rx and OTC drugs and 20 most common CAM therapies.

Rx and OTC Medications Commonly Used ( 5%) by Adults 65 and older (1999 vs.2005) Slone ( ) 1Aspirin 2Acetaminophen 3 Conjugated estrogens 4 Hydrochlorthiazide 5Levothyroxine 6Furosemide 7Ibuprofen 8Atenolol 9Lisinopril 10 Digoxin 11Warfarin 12Triamterine NSHAP ( ) 1Aspirin13Warfarin 2Hydrochlorothiazide14Ezetimibe 3Levothyroxine15Alendronate 4Lisinopril16Lovastatin 5Atorvastatin17Valsartan 6Metoprolol18Omeprazole 7Simvastatin 8Atenolol 9Amlodipine 10Acetaminophen 11Furosemide 12Metformin

Most commonly used ( 3%) Dietary Supplements Among Adults 65 and older (1999 vs.2005) Slone ( ) 1Multivitamin/mineral 2 Vitamin E 3 Calcium 4 Vitamin C 5 Vitamin D 6Magnesium 7Glucosamine 8 Folic Acid 9Ginkgo 10 Garlic 11Zinc NSHAP( )1Multivitamin/mineral 2Calcium 3 Vitamin E 4 Vitamin C 5Glucosamine 6 Vitamin B12 7 Folic Acid 8 Vitamin D 9Chondroitin 10 Omega 3 Fatty Acids 11 Vitamin B6 12 Eye Vitamins 13Magnesium

Medication Interaction Severity Definitions major: life-threatening and/or require medical intervention to minimize or prevent serious adverse events. major: life-threatening and/or require medical intervention to minimize or prevent serious adverse events. moderate: may result in the exacerbation of the patients condition. moderate: may result in the exacerbation of the patients condition. minor: the interaction would have limited clinical effects. minor: the interaction would have limited clinical effects.

Prevalence of Potentially Harmful Medication Interactions

Limitations Cross sectional data Cross sectional data Comparability to previous studies Comparability to previous studies Micromedex® Interaction software Micromedex® Interaction software Major Interactions reported only for commonly used medications. Major Interactions reported only for commonly used medications.

Conclusions Overall increase in the prevalence of medication use and number of commonly used medications among older adults Overall increase in the prevalence of medication use and number of commonly used medications among older adults Types of commonly used Rx, OTC, and dietary supplements varies over time Types of commonly used Rx, OTC, and dietary supplements varies over time Poly-pharmacy is common and increases with age Poly-pharmacy is common and increases with age Self-medication with NonRx is widespread across all older age groups Self-medication with NonRx is widespread across all older age groups Approximately 2.2 million (4%) older adults in the U.S. are at risk for a harmful medication interaction Approximately 2.2 million (4%) older adults in the U.S. are at risk for a harmful medication interaction Half are potentially at risk for GI bleeding Half are potentially at risk for GI bleeding

Implications Up-to-date data on medication use among older adults increasingly important in the assessment of medication-related Quality of care Up-to-date data on medication use among older adults increasingly important in the assessment of medication-related Quality of care National prescription data sources need to incorporate information on all types of medications National prescription data sources need to incorporate information on all types of medications Efforts to minimize harmful interactions should focus on common medications with the highest risk and the oldest age group Efforts to minimize harmful interactions should focus on common medications with the highest risk and the oldest age group Patient safety in older adults requires clinician awareness of current prescription medication and self-medication use patterns Patient safety in older adults requires clinician awareness of current prescription medication and self-medication use patterns

Supported by: Supported by: The University of Chicago Program in Pharmaceutical Policy The University of Chicago Program in Pharmaceutical Policy Chicago Core on Biomeasures in Population-Based Health and Aging Research, Center on Demography and Economics of Aging, NORC and the University of Chicago (P30 AG ) Chicago Core on Biomeasures in Population-Based Health and Aging Research, Center on Demography and Economics of Aging, NORC and the University of Chicago (P30 AG ) National Institute of Health and the National Institute on Aging, Office of Research on Women's Health Office of AIDS Research, and Office of Behavioral and Social Sciences Research (R01AG021487) National Institute of Health and the National Institute on Aging, Office of Research on Women's Health Office of AIDS Research, and Office of Behavioral and Social Sciences Research (R01AG021487) Public use dataset available at: