Validation of the Korean version of the Posttraumatic Growth Inventory using the Rasch model

Area of Science:

• Psychology
• Psychometrics

Background:

• Posttraumatic growth (PTG) involves positive psychological changes after trauma.
• The Korean version of the Posttraumatic Growth Inventory (K-PTGI) was previously shortened to 16 items and a four-factor structure.
• This study reevaluates the K-PTGI's psychometric properties using the Rasch model.

Purpose of the Study:

• To examine the factor structure and item-level properties of the Korean Posttraumatic Growth Inventory (K-PTGI).
• To evaluate the psychometric validity of the K-PTGI using the Rasch model.

Main Methods:

• A sample of 1,500 Korean adults completed an online survey.
• Factor analysis was used to assess the scale's factor structure.
• The Rasch model was applied to analyze item fit, difficulty, and response category appropriateness.

Main Results:

• The K-PTGI exhibited a stable five-factor structure, aligning with the original PTGI model and showing cultural nuances.
• Two spiritually themed items demonstrated misfit, potentially due to cultural expression differences.
• The 6-point Likert scale was confirmed as appropriate for the K-PTGI.

Conclusions:

• The K-PTGI demonstrates robust psychometric validity.
• Future revisions should refine spiritually themed items and create items with lower difficulty to better capture early posttraumatic growth experiences.