Minimum clinically important difference (MCID) of the personal impact of epilepsy scale (PIES).

Introduction: The Personal Impact of Epilepsy Scale (PIES) assesses patient functional status in subscales of (1) seizure impact, (2) medication effects, (3) mood & social status, and (4) overall quality of life. This study was designed to determine the Minimal Clinically Important Change (MCID) in PIES subscale and total scores that demonstrate improvement.

Methods: To ascertain the correspondence of PIES score change and clinical status change (improved, same, worse) in each PIES subscale and total score, we used two distinct retrospective anchor-based assessments of clinical status (patient self-assessment and trained rater assessment) across two clinic visits.