Fig. 2

The Wright person-item map of the Barthel Index for assessing beneficiaries with (n = 300) or without dementia (n = 300) and unsuccessful claimants (n = 228). Notes: # = 5 persons, * = 1 person; M = mean person ability or item difficulty, S = one standard deviation, T = two standard deviations. The vertical line is a continuum representing the measures of person ability (right) and item difficulty (left), plotted in logit units. Person ability and item difficulty increase from bottom to top