The psychometric properties of the Posttraumatic Growth Inventory‑Short Form (PTGI‑SF) in the Spanish population during the COVID‑19 pandemic

Este trabajo recoge la adaptación de la herramienta breve de crecimiento postraumático (PTGI-SF) al contexto de la crisis del COVID-19 en España.

Background: One of the most widely used instruments to measure PTG is the Posttraumatic Growth Inventory-Short Form (PTGI-SF). However, it has not been validated for the Spanish population. This study explored the psychometric properties of the PTGI-SF in adults living in Spain during the COVID-19 pandemic
Methods: The participants were adult inhabitants of Spain (N = 855). They completed the PTGI-SF in July 2020 (two items were added to assess communal PTG), along with the Impact of Event Scale-Revised to measure posttraumatic stress symptoms (PTSS). In November 2020, 592 participants once again completed the PTGI-SF. Evidence of factorial validity was explored with Structural Equations Modeling (SEM). Internal consistency was tested via Cronbach’s α and test-retest reliability via the Intra-class Correlation Coefficient (ICC). Sensitivity and criterion-related validity were assessed through the association of PTGI-SF scores with gender, age, PTSS, and perceived severity of the COVID-19 crisis.
Findings: Results indicated adequate structural validity for an eight-item, four-correlated factors structure of the inventory (CFI= .98, TLI= .98, RMSEA= .05, SRMR= .03). The four factors were: Relating to Others, Personal Strength, Spiritual Change, and Life Value and Opportunities. Communal PTG overlapped with Relating to Others, so it was discarded. This structure demonstrated invariance across random subsamples and gender subsamples. The scores showed good internal consistency (α=.88) and moderate test–retest reliability (ICC=.68). Sensitivity and criterion-related validity were also adequate.
Discussion: The PTGI-SF is an adequate tool to measure PTG during the COVID-19 pandemic. Cultural differences need to be addressed when measuring PTG.