Reliability of pulse diagnosis in traditional Indian Ayurveda medicine

In Ayurveda, pulse diagnosis is an important diagnostic method to assess the status of three doshas (bio-entity: vata, pitta and kapha) in the patient. However, this is only justifiable if this method is reliable. The aim of this study is to test the intra-rater and inter-rater reliability of pulse diagnosis in Ayurveda. A double-blinded, controlled clinical trial was conducted at Sri Sri College of Ayurvedic Science & Research Hospital, Bangalore, India. 15 Ayurvedic doctors examined the pulse of the 20 healthy subjects (10 male and 10 female) twice in a random order without seeing them. Doctors diagnosed various combinations of three bio-entities vata, pitta and kapha based on the qualitative description of pulse pattern in Ayurveda. Cohen's weighted kappa statistic was used as a measure of reliability and hypothesis of homogeneous diagnosis (random rating) was tested. The level of weighted kappa statistics for each doctor was -0.18, 0.12, 0.31, -0.02, 0.48, 0.1, 0.26, 0.2, 0.34, 0.15, 0.56, 0.03, 0.36, 0.21, 0.4 respectively and the hypothesis of homogeneous diagnosis was only significant (p = 0.04) at the 5 % level for one doctor. The kappa values are in general bigger for the group of practitioners who used pulse diagnosis in their practice (p-value 0.04). Moreover, the proportions of ratings were significantly different among doctors (p-values< 0.0005) both when considering all doctors and within the subgroups of non-practitioners, practitioners of pulse diagnosis and pulse diagnosis course takers. Furthermore, doctors diagnosed more frequently combinations of two doshas. Result shows that the kappa values for each doctor range from slight to moderate level of agreement and are even negative for 2 doctors. Moreover, not much evidence was found against the null hypothesis of homogeneous diagnosis demonstrates the low intra-rater reliability of pulse diagnosis; which potentially suggests inconsistency in the pulse diagnosis. The doctors moreover seem to favor different diagnoses since the proportions of ratings vary among doctors, so reproducibility was hard to reach. Moderate level of agreement is observed in the doctors who are more experienced and practicing pulse diagnosis. This variability in the diagnosis indicates the need of standardization of the pulse diagnosis method in Ayurveda