A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers

Background: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. Methods: Blood samples were collected nationwide in 28 laboratories from the seven regions ( ≥ 400 samples/ region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and