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Using repeated measures to correct correlated measurement errors through orthogonal decomposition |
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| Authors: | Chang Yu Sanguo Zhang Christine Friedenreich Charles E Matthews |
| Institution: | 1. Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA;2. School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, China;3. Department of Cancer Epidemiology and Prevention Research, Cancer Control Alberta, Alberta Health Services, Calgary, Canada;4. Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, 6120 Executive Boulevard, Bethesda, MD, USA |
| Abstract: | In a physical activity (PA) study, the 7-day PA log viewed as an alloyed gold standard was used to correct the measurement error in the physical activity questionnaire. Due to correlations between the errors in the two measurements, the usual regression calibration (RC) may result in a biased estimate of the calibration factor. We propose a method for removing the correlation through orthogonal decomposition of the errors, and then the usual RC can be applied. Simulation studies show that our method can effectively correct the bias. |
| Keywords: | Adjusted regression calibration correlated measurement errors orthogonal decomposition physical activity |