Compliance a challenge for older epilepsy patients.

PHILADELPHIA -- Compliance with antiepileptic drugs was worse in the elderly than in younger patients, and noncompliant patients were more likely to have serious sequelae including death, based on results from two separate studies.

Nonadherence among patients aged 65 years or older occurred in 41% of 1,278 patients studied, Dr. Alan B. Ettinger reported at the annual meeting of the American Epilepsy Society. In contrast, in an independent study of 33,658 Medicaid patients in three states the rate of noncompliance among all adults aged 18 years and older was about 26%, reported Annie Guerin, a researcher at Analysis Group Inc. in Boston.

Nonadherence is more likely to be a problem for the elderly because of several factors including their higher likelihood of living alone or having dementia, said Dr. Ettinger, director of the Comprehensive Epilepsy Center at Long Island Jewish Hospital in New Hyde Park, N.Y. The elderly are also more susceptible to complications of noncompliance because of their comorbidities, such as their higher prevalence of osteoporosis, which can boost the risk of bone fracture in a fall during a seizure, Dr. Ettinger said in an interview.

His study included elderly individuals with epilepsy who were patients in any of 30 health plans that covered about 38 million U.S. patients during January 2000-De-cember 2005. Epilepsy patients were identified by at least one diagnosis of epilepsy or nonfebrile convulsions during the study period and by getting at least two prescriptions for antiepileptic drugs. Patients were judged compliant with their medications if they filled prescriptions and had at least one antiepileptic drug on hand for at least 80% of the days when they were prescribed the drug (a medication possession ratio--MPR). Patients with an MPR of less than 80% were considered nonadherent. The average age of the elderly patients in the study was 73 years.

Of the more than 1,200 elderly epilepsy patients identified in the study series, 41% had an MPR of less than 80%. Within the nonadherent group 25% had poor adherence, with MPR rates of less than 60%, Dr. Ettinger said.

Nonadherent patients were much more vulnerable to having a serious seizure, with a 14% rate of serious seizures in patients with a MPR of less than 60%, and a 12% rate in those with a MPR of less than 80%. In compliant patients (MPR of 80% or higher), the rate of serious seizures was about 8%. Nonadherence was also linked to a significant, $2,400 increase in the average cost of health care, compared with the compliant, elderly patients.

Physicians who care for elderly patients with epilepsy need to educate them about the importance of compliance with antiepileptic drugs, and they need to use social services and family members to help maintain compliance. Another important step is to assess how well patients feel when taking antiepileptic drugs. It may be necessary to switch patients to drugs that are better tolerated if adverse effects are an issue. The better tolerated antiepileptic drugs are generally the newer agents, such as gabapentin, pregabalin, lamotrigine, and levetiracetam.

The study was sponsored by GlaxoSmithKline, which markets lamotrigine (Lamictal). Dr. Ettinger is an adviser to and gives lectures for GlaxoSmithKline. Dr. Ettinger is also a professor of clinical neurology at Albert Einstein College of Medicine, New York.

A companion study presented by Dr. Ettinger and his associates reviewed 18,073 adult patients, aged 18-64 years, with epilepsy from more than 40 million people insured by any of 75 health plans in the United States during January 2000-December 2005. During the study period, 2,467 of these patients had a serious seizure.

Adherence to antiepileptic drug prescriptions dropped markedly with time during the first year after prescriptions began, so that by a year after starting a prescription only about 60% of patients were adherent.

The analysis showed a significant link between adherence and the risk of having a serious seizure. Patients who were compliant with their medications and had a MPR of at least 80% were 16% less likely to have a serious seizure than noncompliant patients. Serious seizures were significantly more likely in men, compared with women. And patients who had a change in the type of antiepileptic drug they were prescribed were 2.5-fold more likely to have a serious seizure than those who didn't switch drugs.

Despite this link between drug switching and increased seizure risk, prescribing a simpler dosing regimen using a newer antiepileptic drug may reduce the risk of serious seizures by boosting adherence, Dr. Ettinger and his associates concluded.

A second study of the impact of adherence on outcomes involved 33,658 patients aged 18 years or older with epilepsy who were treated through Medicaid in Florida, Iowa, or New Jersey during 1997-2006. During this time the patients received medication prescriptions for more than 525,000 quarters, and during 26% of these quarters the patients were noncompliant, with a MPR of less than 80%.

After controlling for baseline demographic and clinical differences, nonadherent patients were about threefold more likely to die than adherent patients, reported Ms. Guerin and her associates from the Analysis Group, Inc. in a poster at the meeting. Additional analyses of these data showed that the noncompliant patients were more often age 65 or older, women, nonwhite, and had more comorbidities based on having a higher Charlson comorbidity index. After controlling for baseline demographic and clinical differences, noncompliant patients were more likely to be hospitalized, had more inpatient days, were more likely to require emergency room visits, and had higher health care costs, compared with compliant patients.

The studies by the Analysis Group were also sponsored by GlaxoSmithKline.

BY MITCHEL L. ZOLER

Philadelphia Bureau