The present invention relates to a non-invasive method for assessing the presence and/or severity of a lesion in an organ of an animal, including a human, said method comprising carrying out at least one non-invasive test resulting in a value, preferably a score result, and positioning the at least one value or score result in a class of a detailed classification, such as, for example, a detailed classification based on population percentiles, or on a reliable diagnostic interval (RDI), to be crossed with another RDI. The present invention also relates to a device, preferably a meter, carrying out the non-invasive method of the invention.