Development and Preliminary Psychometric Evaluation of Agni Assessment Scale: A measure of functional digestive capacity based on Ayurveda

Background As traditional systems of medicine gain global popularity and acceptance, it has become essential to validate their unique concepts using evidence-based research methodologies. This study aims to develop a self-assessment tool called the Agni Assessment Scale (AAS) to identify the state of Agni, a key concept in Ayurveda that represents digestive and metabolic functions. It also seeks to evaluate the psychometric properties of the scale. Methods The development of the scale was divided into two phases involving 467 participants from India. In the first phase, an initial pool of items was created through a literature review, consultations with clinicians, and a field study (n=100). The second phase screened the items for their content validity, conducted an exploratory factor analysis (n = 367), and tested for reliability and concurrent validity. Results Preliminary evidence supported the factorial structure of the 26-item Agni Assessment Scale. Exploratory Factor Analysis (EFA) provided support for four subscales: Samagni subscale, Vishamagni subscale, Mandagni subscale, and Tikshnagni subscale. The final version demonstrated acceptable internal consistency (subscale α ranging from .57 to .83), with all subscales except Samagni meeting conventional reliability thresholds. Preliminary concurrent validity analysis indicated a 64% concordance between participants' self-reported Agni states and scale-derived states of Agni. Conclusion: The EFA demonstrated promising psychometric properties and conceptual coherence with Ayurvedic theory, though further validation in clinical and cross-cultural contexts is essential.