title: Comparing biomarker measurements to a normal range: when to use standard error of the mean (SEM) or standard deviation (SD) confidence intervals tests.
abstract: This commentary is the second of a series outlining one specific concept in interpreting biomarkers data. In the first, an observational method was presented for assessing the distribution of measurements before making parametric calculations. Here, the discussion revolves around the next step, the choice of using standard error of the mean or the calculated standard deviation to compare or predict measurement results.
authors.affiliation: a National Exposure Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park , NC , USA.
authors.forename: Joachim D
authors.initials: JD
authors.lastname: Pleil
mesh_terms: D015415:Biomarkers; D016001:Confidence Intervals; D006801:Humans; D012016:Reference Values; D018401:Sample Size; D013223:Statistics as Topic
chemical_list: D015415:Biomarkers
keywords: Confidence interval; sample size; standard error; statistics