Property difference in Mini-Mental State Examination Serial Sevens and World Backwards: Analysis using item response theory

We compared the psychometric properties of two MMSE-J attention tasks—Serial Sevens and World Backwards—using item response theory on individuals with early Alzheimer's disease (CDR-GS 0.5 or 1) from J-ADNI study. Serial Sevens demonstrated higher discrimination power than World Backwards in those with CDR-GS of 0.5. In contrast, differences between these tasks were minimal among individuals with CDR-GS 1. These findings suggest that it may be recommended to clarify which task was used for calculating MMSE total scores, as well as to use the same item calculation method in longitudinal evaluations.