RETRACTED ARTICLE: Improving the measurement of alexithymia in autistic adults: a psychometric investigation and refinement of the twenty-item Toronto Alexithymia Scale

Table 3 Differential item functioning results comparing autistic and general population adults on 9-item Toronto Alexithymia Scale

TAS-20 Item #	χ²(5)	p_FDR	wABC	ESSD	Parameters^a
1	35.30	< 0.001	0.089	− 0.018	a₁, d₁, d₂
2	23.18	< 0.001	0.164	0.157	d₂, d₃
3	65.10	< 0.001	0.433^b	0.670^b	d₂, d₃, d₄
9	26.03	< 0.001	0.064	− 0.021	d₁
11	30.47	< 0.001	0.165	0.001	a₁, d₂, d₃
12	30.19	< 0.001	0.149	− 0.187	d₁
13	57.66	< 0.001	0.064	− 0.022	a₁, d₁, d₂, d₃, d₄
14	61.90	< 0.001	0.031	− 0.022	a₁, d₁, d₂, d₃, d₄

Results indicate omnibus Wald tests of differential item functioning using the iterative anchor-selection method of Cao et al. [137]. P values (p_FDR) are corrected for a 5% false discovery rate using the Benjamini–Hochberg procedure. Parameters that were significantly different between groups when tested alone with follow-up Wald tests (p_FDR < 0.05) are indicated in the Parameters column
wABC weighted area between curves, ESSD expected score standardized difference (in Cohen’s d metric), a₁ slope parameter, d₁–d₄ item intercept parameters (i.e., item “difficulty” parameters)
^aParameters in bold are larger (i.e., more discriminating for a parameters and “easier” for d parameters) in the autistic group. Larger values of a indicate that the item is more strongly related to the latent trait in autistic adults, whereas larger values of d indicate that a given item response is endorsed at lower latent trait levels in autistic adults relative to the general population
^bPractically significant DIF (i.e., wABC > 0.3)

ISSN: 2040-2392