Bland-Altman’s Limits of Agreement (LOA).

a Provides the number of samples with a valid quantitative result (i.e. not below or above the measuring range);b Difference between the reference method and the respective quantRTK;c Difference between the reference method and the quantRTK ±2 SD.d For the saltPAD, three types of interpretation of the results on the cards were done: interpretation by the operator, by an expert reader (a person from the device developer) and an image analysis software; the index provides the information which readings were used.Bland-Altman’s Limits of Agreement (LOA).