Abstract
Fundamental issues emerging from the widespread use of non-invasive techniques in healthcare sciences' research are the reliability and validity. This work presents the reliability analysis of a clinical trial that uses a Finometer and an AGE Reader. The aim is to provide a self-consistent and meaningful reliability analysis concerning Finometer and AGE-Reader devices, something that is often missing in the research field of healthcare sciences and present results could be used to fill up this gap. Since four raters are used for taking measurements in this study, the presented reliability analysis includes tests for the raters as well as for the instruments' internal consistency of the instruments. It was found that both the reported inter-rater reliability and instruments' reliability of internal consistency were found adequately high. In conclusion, Finometer and AGE-Reader devices showed high reliability and the present results can be used as a concrete basis for future studies utilising these devices.