Mosaic single plasma sample method for measuring glomerular filtration rate

Seven single plasma sample methods for measuring glomerular filtration rate (GFR) were evaluated. When compared with GFRs calculated from a slope/intercept method proposed by Russell et al. [6] (using 1 h and 3 h plasma samples) as a reference standard, each single-sample method produced better results in different ranges of GFR (3 h plasma sample was used for all seven single-sample methods). Combining the best single-sample method in each range (mosaic) resulted in a regression line of y = 0.98x + 1.0, with a correlation coefficient of 0.980 and a standard error of estimate of 6.5 ml min-1 in 294 samples. This mosaic method yielded more accurate and realistic GFR values than any other individual single-sample method.