The effect of different analytical platforms and methods on the performance of population-specific adjusted calcium equation

Background A recent attempt to improve the diagnostic value of adjusted calcium addressed a primary care-specific adjusted calcium equation, but validated the new equation for Roche Cobas, BCG and NM-BAPTA methods only. In this study, we aim to validate a population-specific equation for other methods and platforms. Method We collected retrospective patient data-sets from 15 hospital laboratories using a range of commercially available analytical platforms and methods for calcium and albumin measurements. Raw data-sets were collected and filtered according to Payne’s criteria, and separate adjusted calcium equations were derived for hospitalized and primary care patients. Results Mean albumin and calcium results were significantly higher in primary care populations (P