Skip to main content
. Author manuscript; available in PMC: 2017 Nov 24.
Published in final edited form as: Stat Med. 2017 Apr 16;36(17):2697–2719. doi: 10.1002/sim.7302

Table II.

Estimated linear regression models from a bridging study to predict serum concentrations of LC–MS/MS-equivalent 25-hydroxyvitamin D from original radioimmunoassay 25-hydroxyvitamin D for National Health and Nutrition Examination Survey, 2001–2006 [19,20].

Survey Period n Equation Mean Square Error Variance of intercept Variance of slope Covariance of intercept and slope
2001–2001 371 LC–MS/MSequivalent = 6.43435 + 0.95212 * RIAoriginal 83.38 1.00689 0.00024 −0.01362
2003–2004 289 LC–MS/MSequivalent = 1.72786 + 0.98284 * RIAoriginal 85.88 1.61349 0.00036 −0.02179
2005–2006 283 LC–MS/MSequivalent = 8.36753 + 0.97012 * RIAoriginal 112.38 1.89393 0.00052 −0.02779

LC-MS/MS, Liquid chromatography–tandem mass spectrometry; RIA, radioimmunoassay.