External validation of the Memory Assessment Clinics Scale for Epilepsy (MAC-E).

Area of Science:

• Neuropsychology
• Epilepsy Research
• Psychometrics

Background:

• Subjective memory complaints are common in adults with epilepsy.
• The Memory Assessment Clinics Scale for Epilepsy (MAC-E) is a brief self-report measure designed to assess these complaints.
• External validation is crucial to confirm the scale's utility in diverse epilepsy populations.

Purpose of the Study:

• To externally validate the Memory Assessment Clinics Scale for Epilepsy (MAC-E) in a multicenter cohort of adults with focal pharmacoresistant epilepsy.
• To assess the psychometric properties of the MAC-E, including its factor structure, internal consistency, and reliability.

Main Methods:

• A cross-sectional study involving 191 adults with focal pharmacoresistant epilepsy from three U.S. Level 4 epilepsy centers.
• Confirmatory factor analysis (CFA) and Item Response Theory (IRT) models were used to evaluate the MAC-E's structure and performance.
• Statistical measures including CFI, RMSEA, SRMR, Mokken analysis, and McDonald's Omega were employed.

Main Results:

• Confirmatory factor analysis supported the established 5-factor structure of the MAC-E (CFI = 0.989, RMSEA = 0.056, SRMR = 0.069).
• MAC-E items demonstrated high discrimination and coverage across latent traits, with strong internal consistency (McDonald's Omega range: 0.77-0.88).
• Unidimensionality was confirmed through Mokken analysis (all H coefficients > 0.4).

Conclusions:

• The MAC-E is externally validated in an independent, multicenter cohort of adults with epilepsy.
• The findings confirm the MAC-E as a psychometrically sound self-report instrument for assessing everyday memory in adults with epilepsy.
• The MAC-E is suitable for use in both clinical practice and research settings for evaluating memory abilities.