Using Evidence Factors to Clarify Exposure Biomarkers.

Using Evidence Factors to Clarify Exposure Biomarkers. Am J Epidemiol. 2020 Jan 08;: Authors: Karmakar B, Small DS, Rosenbaum PR Abstract A study has two evidence factors if it permits two statistically independent inferences about one treatment effect such that each factor is immune to some bias that would invalidate the other factor. Because the two factors are statistically independent, the evidence they provide may be combined using methods associated with meta-analysis for independent studies, despite using the same data twice in different ways. We illustrate evidence factors, applying them in a new way in investigations that have both an exposure biomarker and a coarse external measure of exposure to a treatment. To illustrate, we consider the possible effects of cigarette smoking on homocysteine levels, with self-reported smoking and a cotinine biomarker. We examine joint sensitivity of two factors to bias from confounding, a central aspect of any observational study. PMID: 31912138 [PubMed - as supplied by publisher]
Source: Am J Epidemiol - Category: Epidemiology Authors: Tags: Am J Epidemiol Source Type: research