Abstracts

RATIONALE: It is not uncommon for large, multi-center clinical trials to have difficulty maintaining adequate enrollment. Significant medical, social, and economic problems associated with aging interfere with the ability of older patients to participate in research studies. Investigators should consider these recruitment challenges when planning research in this age group. METHODS: This was a retrospective analysis of eligibility criteria from VA Coop Study #428, "Treatment of Seizures in the Elderly Population." Eighteen VAMC's are presently participating in a study to evaluate the efficacy and tolerability of gabapentin (GBP), lamotrigine (LTG), and carbamazepine (CBZ) in the treatment of seizures in individuals 60 or older. Screening records were reviewed to determine reason(s) for ineligibility into the trial. RESULTS: 736 patients have been screened. Of these, 333 were enrolled and 403 (54.8%)were excluded. The number excluded is likely to be an underestimate since screening forms were not done on every potential patient. The most common exclusion reasons are unstable medical disorder 23.3%, unable to give informed consent 22.3%, satisfied with current treatment 20.3%, questionable compliance 19.6%, no seizure last 3 months 17.1%, adequately treated 16.6%, and refused 15.4%. Other exclusions include age < 60 14.9%, treated with study drug 7.9%, psychiatric disorder 6.7%, alcohol withdrawal 5.7%, metabolic seizures 5.2%, chronic barbiturates 4.2%, non-vets 4.2%, malignant brain tumor 4%, allergic to study drug 1.4%, use of street drugs 1.5%, enrolled in other research 0.7%, and acute CNS infection 0.5%. Most common reasons for refusal were patient refused 67.7%, family refused 11.3%, and travel 8.1%. CONCLUSIONS: Co-morbid diseases impact the older patient's ability to participate in clinical trials. Cognitive impairment related to aging contributes to the inability of older patients to understand and give informed consent. Elderly patients are more likely to refuse participation in research than younger adults. Approval from family members/caregivers becomes more important in determining participation.