Objective: Intact parathyroid hormone is used for diagnostic follow up in chronic kidney disease mineral bone disorder. Studies have shown that there was considerable bias between methods intact parathyroid hormone assays. This study has investigated the variation between intact parathyroid hormone assays using Access intact parathyroid hormone and Roche intact parathyroid hormone and if there is a bias, how this affect clinical decision level.

Materials and Methods: We used blood sample of 41 patients with chronic kidney disease. Intact parathyroid hormone levels were measured with Access intact parathyroid hormone assay kit through UniCel DxI 800 autoanalyser (Beckman Coulter, Inc., Fullerton, U.S.A.) and Roche intact parathyroid hormone assay kit through Cobas e 601 autoanalyser (Roche Diagnostics GmbH, Mannheim, Germany). The results were divided into groups according to the decision points determined by the manuals. Results were statistically evaluated.

Results: In Passing-Bablock analyse we found the following equation, y= -9.56 + 0.91 x (confident interval for intercept: -24.52 to 0.41, for slope: 0.87 to 0.950). There was no significant deviation from linearity (p>0.05). We found a 16.1 % difference between two methods in Bland–Atman plot analysis. The moderate agreement was found between clinical decision points determined by two methods using the Kappa test (κ = 0.437).

Conclusion: We show that there is moderate agreement between Access intact parathyroid hormone assay and Roche intact parathyroid hormone assay results. We also show that there are differences between both methods. Clinicians should be informed about the bias between the methods and this bias should be taken into account in clinical decision point.