A Qualitative Approach to Assessing the Validity of the Posttraumatic Growth Inventory

The Posttraumatic Growth Inventory (PTGI) is the most commonly used measure of positive psychological change that can result from negotiating a traumatic experience. While the PTGI has strong internal reliability, validity studies are still sparse. The present research details trauma survivors' understanding of items comprising the PTGI in order to qualitatively assess content validity. Participants were 14 trauma survivors who completed the PTGI and participated in a semistructured interview. Thematic analysis was conducted on participants' transcribed interviews. One latent theme was identified reflecting that questions were consistently understood. A relationship was found between the constituent themes identified and the five factors of the PTGI. Participants answered the PTGI statements in a way that is consistent with the purpose of the instrument, with only a small discrepancy found when some participants used the PTGI scale to indicate when a decrease in an element of the inventory had been experienced. Overall results supported the content validity of the PTGI.