ABSTRACT
The variation of the lipid profile by sex in patients with coronary artery disease (CAD) is well known. However, when the sample size is small, it is difficult to establish this association. This study uses the Bayesian paradigm to understand the association between sex and lipid profile in patients with CAD and compares the results with classical approaches. The study is based on a secondary analysis of CAD patients' data (n = 1,045) from NHANES (2015–2016), older than 50 years for which lipid profile measurements were available. The clinical diagnosis of CAD was positive in 91 individuals and negative in 945. The comparison of differences in lipid profiles by sex was performed under the classical paradigm (independent sample t-test and Wilcoxon rank sum test) and Bayesian. CAD-positive men were younger (54–80 years) than women (57–80 years). Lipid parameters (total cholesterol, LDL, direct HDL, non-HDL) differed significantly according to sex, under both classical and Bayesian paradigms; except triglycerides and two proportions (TC: HDL, LDL: HDL). However, the Bayesian paradigm has suggested differences even for triglycerides and two sex ratios. This chapter's study demonstrates the application of Bayesian t-test in the case of a small sample size. This clearly suggests that even when the sample size is small, the Bayesian paradigm closely approximates our prior knowledge of the lipid profile as a risk factor for the development of CAD. The Bayesian paradigm revealed the importance of clinical parameters (triglycerides, TC: HDL and LDL: HDL), which remained hidden under the classical t-test and the nonparametric Wilcoxon rank sum test.
