Epilepsy in the Elderly: Risk factors as Targets for Prevention? This study is funded by VA Health Services Research and Development Service (IIR ) Mary Jo V. Pugh, PhD, RN

Collaborators Dan R. Berlowitz, MD, MPH Janice Knoefel, MD Joyce Cramer, BS Omotola Hope, MD Anne VanCott, MD Eric Mortensen MD, MSc And the TIGER Research Team

Background Epilepsy is one of the most common chronic neurological diseases Incidence of epilepsy is highest in the elderly

Incidence of Epilepsy Rochester, Minn Hauser, Epilepsia, 33: Age Male Female Total Incidence / 100,000

Aging in America: Implications for Epilepsy Now30% of new cases are elderly % of new cases will be elderly

Why Try to Prevent Epilepsy in the Elderly? Epilepsy is associated with high costs –Lifetime cost per patient (1990 dollars) $4,272: remission after initial diagnosis and treatment $138,602 for persons with intractable and frequent seizures (30-40% of epilepsy population). Begley et al.1994, Epilepsia Epilepsy in the elderly affects HRQoL –Affects both physical and mental aspects

HRQoL in Older Veterans ScaleEpilepsy StatusAdjusted Score* Physical FunctionNo Epilepsy (0.25) Chronic Epilepsy (0.48) New Epilepsy (1.41) Mental HealthNo Epilepsy68.77 (0.19) Chronic Epilepsy64.79 (0.36) New Epilepsy61.50 (1.05) *Controlling for physical and mental comorbidities defined by Selim et al Pugh et al International Review of Neurobiology

Purpose Identify risk factors for new-onset epilepsy in older patients –Risk factors may then be evaluated as targets for prevention or delay of epilepsy onset in older patients

Data Sources VA National Patient Care Database (FY 99-FY00) Medicare Data procured by Veterans Information Resource Center (FY 99-FY00) –Used only to identify individuals with epilepsynot available for non-epilepsy patients VA National Pharmacy Benefits Management Database (FY 99-00)

Methods PopulationPopulation –Veterans >65 years old –Received at least on drug from VA in FY00 –Received VA care in FY99 & FY00 Dependent Variable: Onset EpilepsyDependent Variable: New Onset Epilepsy First diagnosis of epilepsy based on ICD-9- CM Code ( convulsion; 345 epilepsy)First diagnosis of epilepsy based on ICD-9- CM Code ( convulsion; 345 epilepsy) Treatment with anti-epileptic drugTreatment with anti-epileptic drug –No indication of epilepsy= Geriatric Cohort Compared Risk Factors in Epilepsy Cohort and Geriatric CohortCompared Risk Factors in Epilepsy Cohort and Geriatric Cohort

CHARACTERISTICS IDENTIFIED IN VA DATABASES DEMOGRAPHICDEMOGRAPHIC –Age, Sex, Race CNS DISORDERSCNS DISORDERS –Cerebrovascular Disease –Dementia –Brain Tumor –Recent Serious Head Injury –Other Neurological Diseases (e.g. MS, Parkinson's Disease) SYSTEMIC DISORDERSSYSTEMIC DISORDERS –Cardiovascular Disease –Peripheral Vascular Disease –Hypertension –Diabetes –Obesity –Hypercholesterolemia

RESULTS: DEMOGRAPHIC VARIABLES RESULTS: DEMOGRAPHIC VARIABLES New Onset Epilepsy N=1,843 Geriatric Cohort N=1,023, yrs yrs 85+ yrs 52% (n=966) 44% (n=818) 3% (n=3) 3% (n=3) 55% (n=558,661) 42% (n=430,125) 3% (n=34,590) 3% (n=34,590) MenWomen 98% (n=1,813) 2% (n=30) 2% (n=30) 98% (n=1,002,806) 2% (n=20,507) 2% (n=20,507) Black** WhiteHispanicOther/Unknown 18% (n=324)** 65% (n=1,204) 5% (n=83) 5% (n=83) 12% (n=232) 9% (n=92,662)** 9% (n=92,662)** 67% (n=683,615) 4% (n=44,619) 4% (n=44,619) 20% (n=36,842) ** p<.001

RESULTS: NEUROLOGICAL RISK FACTORS New Onset Epilepsy N=1,843 Geriatric Cohort N=1,023,376 Stroke ** 40% (n=700) 15% (n=151,971) Dementia ** 16% (n=308) 7% (n=67,236) 7% (n=67,236) Brain Tumor ** 2% (n=29) 2% (n=29) 0.6% (n=5,833) Other CNS Disorders ** 9% (n=160) 9% (n=160) 4% (n=36,842) 4% (n=36,842) ** p<.001

SYSTEMIC VASCULAR RISK FACTORS New Onset Epilepsy N=1,843 Geriatric Cohort N=1,023,376 Cardiovascular Disease ** 37% (n=674) 30% (n=312,334) Peripheral ** Vascular Disease 20% (n=363) 16% (n=164,150) Hypertension ** 75% (n=1,389) 72% (n=734,477) Diabetes 31% (n=566) 30% (n=301,487) Obesity ** 10% (n=181) 13% (n=137,542) Hyperlipidemia ** 34% (n=683) 42% (n=434,628) ** p<.001

LOGISTIC REGRESSION: CNS Risk Factors For New-Onset Geriatric Epilepsy ODDS RATIO 95% CI Cerebrovascular Disease Dementia Recent Serious Head Trauma Brain Tumor Other CNS Disorders Controlling for demographic and systemic disease characteristics

LOGISTIC REGRESSION: Systemic Risk Factors For New-Onset Geriatric Epilepsy ODDS RATIO 95% CI CardiovascularDisease Peripheral Vascular Disease Hypertension Diabetes Obesity Hyperlipidemia Controlling for demographic and neurological risk factors

LOGISTIC REGRESSION: Lipid Lowering Drug Use ODDS RATIO 95% CI Lipid lowering drugs: STATINS Lipid lowering drugs: OTHER Controlling for demographic, neurological and systemic risk factors

LIMITATIONS Use of administrative data to identify study cohortsUse of administrative data to identify study cohorts –Chart abstraction validation confirmed that new- onset epilepsy was accurately identified using our algorithm –Diagnosis of obesity based on ICD 9 codes –Statin use based on pharmacy data Healthy User Effect?Healthy User Effect? Did not use Medicare data for identifying comorbid conditions.Did not use Medicare data for identifying comorbid conditions. –May be underestimates

CONCLUSIONS Consistent with previous research stroke was the strongest risk factor for new-onset epilepsy in older patientsConsistent with previous research stroke was the strongest risk factor for new-onset epilepsy in older patients Systemic risk factors were not associated with an independent riskSystemic risk factors were not associated with an independent risk –Association of systemic risk factors may work indirectly through increased risk for stroke and dementia in older men Potential protective mechanism of statins may be due to reduced risk for stroke.Potential protective mechanism of statins may be due to reduced risk for stroke.

Impact Use of statins for primary prevention of myocardial infarction and stroke may have additional benefits by reducing risk of epilepsy. Prevention of epilepsy will benefit both the healthcare system and the patient.

Thank You! Contact Information: Mary Jo V. Pugh PhD, RN HSR&D, San Antonio