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. 2024 Feb 23;67(1):e19. doi: 10.1192/j.eurpsy.2024.14

Table 2.

Item parameters from IRT

Item α β1 β2 β3 β4 β5 β6 β7 β8 β9 β10 β11 β12
  1. Word recall
 1.92***** −4.82 −4.45 −4.08 −3.33 −2.46 −1.55 −0.66 0.19 1.21 2.59*
  1. Commands
 1.32*** −0.06 1.02 1.84 3.34* 4.63*
  1. Naming
 1.28*** −0.17 −0.09 −0.06 1.51 2.68*
  1. Constructional praxis
 0.96*** −1.55 0.95 2.00* 3.98* 5.93*
  1. Ideational praxis
 1.12*** 0.01 1.36 2.09* 2.63* 3.34*
  1. Orientation
 1.41**** −2.26 −1.33 −0.66 −0.07 0.62 1.3 2.35* 4.45*
  1. Word recognition
 1.25*** −4.41 −3.17 −2.25 −1.56 −1.08 −0.58 −0.14 0.3 0.76 1.22 1.74 2.49*
  1. Spoken language ability
 −0.59* 3.80* 2.82* 2.55* 2.51* −2.47
  1. Comprehension of spoken language
 −0.62* 3.08* 2.22* 2.13* 2.11* −2.02
  1. Remembering test instruction
 −0.76* 2.84* 1.86 1.51 0.71 −2.18
  1. Word finding difficulty
 −0.66* 2.57* 1.69 1.35 1.32 −1.25

Note: Item discrimination parameters (α) map the ability of an item to discriminate latent cognitive impairment levels. Discrimination parameter values (α) that range from 0.01 to 0.24 are very low, 0.25 to 0.64 low, 0.65 to 1.34 moderate, 1.35 to 1.69 high, and over 1.7 are very high (Baker, 2001). βs are standardized estimates of the 0.5 probability of endorsing a higher cognitive impairment rating where negative values indicate progression to the next response is unlikely.