title: Sensitivity of regression calibration to non-perfect validation data with application to the Norwegian Women and Cancer Study.
abstract: Measurement error occurs when we observe error-prone surrogates, rather than true values. It is common in observational studies and especially so in epidemiology, in nutritional epidemiology in particular. Correcting for measurement error has become common, and regression calibration is the most popular way to account for measurement error in continuous covariates. We consider its use in the context where there are validation data, which are used to calibrate the true values given the observed covariates. We allow for the case that the true value itself may not be observed in the validation data, but instead, a so-called reference measure is observed. The regression calibration method relies on certain assumptions.This paper examines possible biases in regression calibration estimators when some of these assumptions are violated. More specifically, we allow for the fact that (i) the reference measure may not necessarily be an 'alloyed gold standard' (i.e., unbiased) for the true value; (ii) there may be correlated random subject effects contributing to the surrogate and reference measures in the validation data; and (iii) the calibration model itself may not be the same in the validation study as in the main study; that is, it is not transportable. We expand on previous work to provide a general result, which characterizes potential bias in the regression calibration estimators as a result of any combination of the violations aforementioned. We then illustrate some of the general results with data from the Norwegian Women and Cancer Study.
authors: Department of Mathematics and Statistics, University of Massachusetts, U.S.A.
authors: John P
authors: JP
authors: Buonaccorsi
authors: Ingvild
authors: I
authors: Dalen
authors: Petter
authors: P
authors: Laake
authors: Anette
authors: A
authors: Hjartåker
authors: Dagrun
authors: D
authors: Engeset
authors: Magne
authors: M
authors: Thoresen
mesh_terms: D015982:Bias; D002138:Calibration; D003110:Colonic Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D015930:Diet Records; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008137:Longitudinal Studies; D008460:Meat / Q000706:statistics & numerical data; D009664:Norway / Q000453:epidemiology; D016017:Odds Ratio; D012016:Reference Values; D012042:Registries; D012044:Regression Analysis; D018570:Risk Assessment / Q000379:methods; D017747:Seafood / Q000706:statistics & numerical data
keywords: measurement error; nutritional epidemiology; regression calibration; sensitivity analysis; validation data