Besselink NJ, et al. - In order to measure joint inflammation of rheumatoid arthritis (RA) patients, and thus disease activity, as well as to evaluate (patho-) physiological findings that could lead to misclassification of inflammation, researchers aimed to develop an optical spectral transmission (OST) model. They noted that by OST, the misclassification of inflammation was relatively rare ie 17%. It was discovered that for analyzing the joints inflammation of the hands and wrists of RA patients, OST was a sensitive, specific and objective technique, even though the risk of misclassification was raised by the bone and tendon pathology.