Are Older Women More Likely to Get Inappropriate Drugs?

1. Are Older Women More Likely to Get Inappropriate Drugs? Arlene S. Bierman, MD, MS Ontario Women’s Health Council Chair in Women’s Health Centre for Research in Inner City Health St. Michael’s Hospital June 28, 2005

2. Potentially Inappropriate Prescribing in the Elderly (PIPE) Study • Mary Jo V. Pugh PhD, RN 5,6 • B. Graeme Fincke, MD 1,2 • Amy Rosen, PhD 1,2 • Fran Cunningham, PharmD 4 • Bei-Hung Chang, ScD 1,2 • Megan Amuan MPH 1 • Muriel Burke, PharmD 4 • Irfan Dalla 3 • Dan Berlowitz, MD, MPH 1,2 1Center for Health Quality, Outcomes and Economic Research, Bedford VA; 2 Boston University School of Public Health; 3 University of Toronto; 4 Pharmacy Benefits Management Strategic Healthcare Group, Hines VA and University of Chicago, Illinois 5Veterans Evidence-based Research, Dissemination, and Implementation Center, 6South Texas Healthcare System, Audie L. Murphy Division, San Antonio, Texas; University of Texas Health Science Center at San Antonio

3. Inappropriate Prescribing in the Elderly • Prescribing of drugs for which potential harms outweigh potential benefits is a major patient safety concern in the elderly. • Inappropriate prescribing increases risk for falls, hip fractures, cognitive impairment, diminished independence, and death. • Studies consistently find that 20-27% of older Americans receive drugs identified as inappropriate, with little to no improvement in nearly two decades.

4. Gender Differences in Potentially Inappropriate Prescribing • Prior studies of community-dwelling elders have suggested that older women were more likely to receive potentially inappropriate drugs than men. • No prior study has examined whether gender differences in potentially appropriate use of these drugs could explain this or the factors associated with gender differences inappropriate prescribing. • Examination of the patterns and correlates of these gender differences can provide evidence to develop and implement effective quality improvement interventions.

5. Study Objectives • To assess gender differences in rates of inappropriate prescribing • To assess whether gender differences are explained by gender differences in potentially appropriate indications for these drugs. • To examine gender differences in the correlates of inappropriate drug use.

6. Methods:Data Sources • Multiple Linked US Veterans Administration (VA) Data Sets • Administrative Data: Demographics • Inpatient Records: Diagnoses and Utilization • Outpatient Records: Diagnoses and Utilization • National Ambulatory Pharmacy Data: Drugs, Dose, Duration • Veterans Health Survey: Race/Ethnicity

7. Cohort Identification At least one outpatient visit in Fiscal Year (FY)1999 and FY 2000 > 65 years of age October 1, 1999 Study Population

8. Potentially Inappropriate Prescribing: Beers Criteria • Potentially Inappropriate Prescribing in the Elderly (Beers, 1991,1997 update 2003). • Explicit criteria, expert consensus panel • 33 drugs considered inappropriate regardless of diagnosis (disease-independent) • dose limitations • drug-drug/drug-disease interactions • Controversial because clinicians argued that some drugs may be appropriate for specific patients in certain circumstances

9. Outcome Variable:Diagnosis-Adjusted Inappropriate Prescribing • AHRQ (US Agency for Healthcare and Quality) expert consensus panel - Grouped 33 Beers disease-independent drugs into 3 categories using modified Delphi process; Always-avoid : 11 drugs Rarely-appropriate : 8 drugs Some-indications : 14 drugs • Diagnosis-adjusted PIPE: Algorithms develop using ICD-9 codes and pharmacy data to adjust for potentially appropriate use.

10. Covariates:Patient Characteristics • Demographics - Age, sex, race/ethnicity -1999 large Health Survey of Veterans provided missing race data • Physical and Psychiatric Comorbidity - Disease burden assessment by Selim’s physical and psychiatric Comorbidity Index - Assessed comorbidity status for 3 years (FY98-00) • # psychiatric diagnoses • # physical diagnoses • Number of unique medications (FY 00)

11. Covariates Characteristics of Care • Type of Care Received (FY 99) • Number of Primary Care Visits • Number of Different Specialty Clinics • Geriatric Care • Long-term Care, Medical or Psychiatric Hospitalizations • Outpatient visits used to assess continuity of care number of outpatient visits in primary care (FY 99) Total number of outpatient visits

12. Method - Analysis • We determined the prevalence of any use of potentially inappropriate drugs among men and women. Then, we used the VA PIPE study algorithms to examine the proportion of this use that may have been appropriate and whether the proportion that remained inappropriate differed by gender. • Using logistic regression we determined the unadjusted and adjusted odds ratios of women receiving diagnosis-adjusted inappropriate drugs compared to men both for individual agents and by drug category (always avoid, rarely appropriate, and rare indication). Patient and care characteristics were included as covariates. • Logistic regressions stratified by gender were conducted to examine gender differences in factors associated with receipt of inappropriate medications.

13. Gender Differences in Use of Inappropriate Drugs All comparisons are significant with P< 0.0001

14. Gender Differences Proportion Inappropriate – Some Indication

15. Odds of Receiving Inappropriate Drugs:Diagnosis Adjusted OR (F vs. M) *Adjusted for demographics, comorbidities, unique meds & characteristics of care

16. Gender Differences in Diagnosis-Adjusted Use of Individual Agents: Always Avoid *Adjusted for demographics, comorbidities, unique meds & characteristics of care

17. Gender Differences in Diagnosis-Adjusted Use of Individual Agents: Rare Indication *Adjusted for demographics, comorbidities, unique meds & characteristics of care

18. Gender Differences in Diagnosis-Adjusted Use of Individual Agents: Some Indication *Adjusted for demographics, comorbidities, unique meds & characteristics of care

19. Drugs less likely to be received by women – Some Indication *Adjusted for demographics, comorbidities, unique meds & characteristics of care

20. Correlates of Inappropriate Prescribing Age, continuity of care, long-term care, medical or psychiatric hospitalizations included in model.

21. Conclusions • Older women were more likely to receive inappropriate medications than older men, even after accounting for a liberal set of indications. • Analgesic, psychotropic, and anticholinergic medications that should be avoided contribute to higher rates of inappropriate drug use among older women. • Psychiatric comorbidity is a predictor of inappropriate drug use in men but not in women.

22. Conclusions • Receipt of geriatric care was equally protective for men and women, though only a small proportion of the sample received this care. • Men and women did not differ in proportion of drugs that were inappropriate, inappropriate dosing, or duration.

23. Limitations • While some use is classified as potentially appropriate often safer or more effective options exist. • Data may not capture all drugs received by the cohort, as those who have other drug coverage may have received medications outside the VA. • VA population may limit generalizability. • A recent update of the Beers criteria added additional medications to the list of disease-independent drugs.

24. Implications • Because of these differences studies on inappropriate prescribing should examine gender differences when possible. • Efforts to improve the quality of medication management in the elderly should address gender differences in prescribing patterns. • Improved access to geriatric care may decrease rates of inappropriate prescribing.