Costs and benefits of item reduction: The abridgment of the Emotion Regulation Questionnaire (ERQ)

Shortening existing instruments is a highly required procedure, as short scales may have several advantages over the long versions, especially in time and/or resources restrictions. However, abbreviated forms may be weaker than their parent versions from both content coverage and psychometric robustness. Also, the abridgment of instruments is often lacking in methodological strictness, and the potential drawbacks of the shortened scales are rarely reported. The current study aims to describe the whole process of scale shortening, emphasizing the potential costs and benefits, in terms of balance between time-resource savings and loss of validity and reliability. We shortened the Emotion Regulation Questionnaire (ERQ), involving a sample of 459 participants (53.2% males). Item reduction was driven by searching to preserve the content breadth of the construct and scale's psychometric quality. Our results supported the two-factor structure of the measure (Cognitive Reappraisal and Expressive Suppression), χ²₍₈₎ = 11.357 ns, CFI = 0.995, TLI = 0.990, RMSEA = 0.030 (0.000-0.067), SRMR = 0.031, and three items were selected for each subscale. The two intended factors showed good levels of reliability (α > 0.710). A latent variable model was performed to evaluate how the original ERQ and our proposed short version (ERQS) were related to depression, anxiety, and stress: A similar pattern of associations was found, with Cognitive Reappraisal (negatively) and Expressive Suppression (positively) reporting significant but weak associations. The ERQ-S can be beneficial over the original version, as it effectively assesses the two emotion regulation strategies with a trivial loss in reliability and predictive validity.