The impact of epilepsy on subjective health status.

Epilepsy is a chronic disorder that has complex effects on many aspects of personal health. Recent advances in the methods to reliably and validly assess subjective health status have allowed major advances in our understanding of these diverse effects, and have also provided evidence to guide treatment and future research. Studies that have included measures of quality of life, patient preferences, and disability in epilepsy have shown that the magnitude of the adverse effects of recurrent seizures on many aspects of subjective health status is as large as that seen with diabetes mellitus and active cardiovascular disease. Studies of patient-oriented, comprehensive outcomes after epilepsy surgery indicate positive treatment effects in broad areas of function and well-being. Although few trials of epilepsy drugs have included health outcome instruments, available studies suggest that greater than 50% seizure reduction is associated with improved quality of life. Adverse medication effects and depression appear to have a strong association with subjective health status in epilepsy, independent of seizure frequency.