Operationalizing near‑death experiences: Stability of the NDE Rasch hierarchy over two decades.

Area of Science:

• Psychology
• Psychometrics
• Neuroscience

Background:

• Near-death experiences (NDEs) are complex phenomena studied for decades.
• Existing scales like the NDE Scale and NDE-C aim to quantify NDEs.
• Psychometric validation is crucial for reliable measurement of NDE phenomenology.

Purpose of the Study:

• To conduct the first comprehensive psychometric comparison of Greyson's NDE Scale and Martial et al.'s NDE-C Scale.
• To evaluate the structural validity and item performance of both scales using Rasch modeling.
• To determine the most robust and reliable measure for assessing NDE phenomenology.

Main Methods:

• Rasch modeling and differential item functioning analyses were applied.
• 705 individuals reporting near-death experiences completed both the NDE Scale and NDE-C Scale.
• Item hierarchies and category structures of both scales were rigorously evaluated.

Main Results:

• Both scales measure the same construct of NDE phenomenology (r = 0.98).
• Rasch analysis revealed limitations in the NDE-C's category structure and novel items.
• The NDE Scale demonstrated long-term structural stability and psychometric robustness.

Conclusions:

• The original NDE Scale is recommended due to its conceptual coherence and psychometric strength.
• Rasch scoring and a cut-off of 7 are advised for the NDE Scale.
• Rasch modeling is valuable for NDE research and theory building.