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. 2021 Jun 29:9:e11639.
doi: 10.7717/peerj.11639. eCollection 2021.

What do alexithymia items measure? A discriminant content validity study of the Toronto-alexithymia-scale-20

Elke Veirman #  1 , Dimitri M L Van Ryckeghem #  1   2   3 , Gregory Verleysen  4   5 , Annick L De Paepe  1 , Geert Crombez  1
Affiliations

What do alexithymia items measure? A discriminant content validity study of the Toronto-alexithymia-scale-20

Elke Veirman et al. PeerJ. .

Abstract

Background: Questions have been raised about whether items of alexithymia scales assess the construct alexithymia and its key features, and no other related constructs. This study assessed the (discriminant) content validity of the most widely used alexithymia scale, i.e., the Toronto Alexithymia Scale (TAS-20).

Methods: Participants (n = 81) rated to what extent TAS-20 items and items of related constructs were relevant for assessing the constructs 'alexithymia', 'difficulty identifying feelings', 'difficulty describing feelings', 'externally-oriented thinking', 'limited imaginal capacity', 'anxiety', 'depression', and 'health anxiety'.

Results: Results revealed that, overall, the TAS-20 did only partly measure 'alexithymia'. Only the subscales 'difficulty identifying feelings' and 'difficulty describing feelings' represented 'alexithymia' and their intended construct, although some content overlap between these subscales was found. In addition, some items assessed (health) anxiety equally well or even better.

Conclusions: Revision of the TAS-20 is recommended to adequately assess all key features of alexithymia. Findings with the TAS-20 need to be interpreted with caution in people suffering from medical conditions.

Keywords: Alexithymia; Content validation; Discriminant content validity method; TAS-20.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Figure 1
Figure 1. Estimates and associated 95% credibility intervals of the relevance score for the TAS, PA, PD, and SHAI for alexithymia, anxiety, depression, and health anxiety.
TAS, Toronto Alexithymia Scale–20; PA, PROMIS® Item Bank v1.0-Emotional Distress-Anxiety–Short Form 4a; PD, PROMIS® Item Bank v1.0–Emotional Distress-Depression–Short Form 4a; SHAI, Short Health Anxiety Inventory.
Figure 2
Figure 2. Estimates and associated 95% credibility intervals of the relevance score for each TAS subscale on alexithymia, anxiety, depression, and health anxiety (A), and the alexithymia key features (B).
TAS, Toronto Alexithymia Scale–20; PA, PROMIS® Item Bank v1.0-Emotional Distress-Anxiety–Short Form 4a; PD, PROMIS® Item Bank v1.0–Emotional Distress-Depression–Short Form 4a; SHAI, Short Health Anxiety Inventory.
See this image and copyright information in PMC

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