Abstracts

Informed consent requires that patients who are potential research subjects be informed that participation in a clinical drug study may not improve epilepsy because the drugs studied may not be efficacious. This is especially true for placebo-controlled trials in which no efficacy in the placebo arm is expected. This discourages some patients from participating because they infer that only a limited number of subjects will improve. It is our impression that participating in a clinical trial improves seizure control regardless of the specific drug[apos]s efficacy. Demographic and seizure frequency data from patients entering antiepileptic drug studies at our institution from January 1999 to February 2004 were collected. Subjects were excluded if follow-up was less than 6 months, seizure calendars were not obtained, or they were not seen beyond the screening visit. Seizure frequency was collected from seizure calendars separately for complex partial (CPS), secondary generalized (SGTC) and all types combined. Seizure frequencies were collected from seizure calendars. Frequency at baseline was defined as that recorded during the baseline of the study or documented at study entry. [quot]Frequency at follow-up[quot] was defined as the frequency during the 6 months after achieving a steady dose of the drug in an open label study. If patients did not participate in an open label study, then the 6 months after exiting the study was used. Frequency at baseline was compared to seizure frequency at follow-up by Wilcoxon rank-sum tests. 42 subjects were reviewed from 8 studies; 22 starting in double-blind studies and 20 in pharmacokinetic or tolerability open-label studies. Mean age was 27[plusmn]13 and 25 were women. All had partial-onset seizures. CPS frequency decreased from 25 to 15 per month (p=0.005). SGTC occurred in only 12 and monthly seizure frequency was unchanged (6.9 at baseline and 5.4 at follow-up, p=0.85). Mean combined seizure frequency decreased from 32 to 20 per month (p=0.003) with an absolute decrease in 37, unchanged in 1 and worsened in 4. Among the 7 who did not continue in an open label study, 5 improved, 1 was unchanged and 1 worsened. Participating in clinical drug studies for epilepsy improves seizure frequency. Some contribution comes from efficacy of the drugs used, but patients improve even when they do not continue to receive the experimental drug, suggesting the close follow-up and education provided by study participation provides additional benefit. The findings should encourage study participation.