Agreement of Urine Specific Gravity Measurements Between Manual and Digital Refractometers

Abstract

Negligible differences were exhibited between PIP and DIP, with both displaying acceptable reliability and validity compared with the MAN. However, the Bland-Altman analysis suggests underestimation bias for the DIP and PIP as Usg increases, with the potential for rare but substantial underestimation when using PIP that should be recognized by clinicians, particularly when used as a screening measure in weight-class sports.