Comparison of Dependent Deattenuated Correlation Coefficients

• Activity Number: 35
• Type: Contributed
• Date/Time: Sunday, August 4, 2013 : 2:00 PM to 3:50 PM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Bernard Rosner*+ and Wei Wang and Eileen Hibert
• Companies: Harvard Medical School and Brigham & Women's Hospital and Brigham & Women's Hospital
• Keywords: biomarker ; deattenuated ; coefficients ; correlation ; beta carotene

Abstract

A marker of validity of a dietary instrument is how well it correlates with a relevant biomarker. For example, there are different methods of assessing dietary Beta carotene (e.g., 24-hr recall, FFQ, diet record); a natural question is which measure correlates most strongly with plasma Beta carotene. Indeed, there already exist methods for comparing dependent correlation coefficients (Wolfe, 1976; Steiger, 1980). However, each of these methods has associated random error. A related question is after correcting for random error, which instrument correlates most highly with plasma Beta carotene. Since these correlations are assessed from the same subjects, a more general question is how can we compare dependent deattenuated correlation coefficients. This is a generalization of previous work for obtaining confidence limits for a single deattenuated correlation coefficient (Rosner & Willett, 1988). We have developed methods of estimation that account for the dependence in correlation estimates and tested them in simulation studies, showing adequate type I error under a variety of parameter settings. We also will illustrate the methods in a dataset from the Nurses' Health Study.