The Use of Parametric and Nonparametric Methods to Study the Effects of Smoking on High-Density Lipoprotein Cholesterol
Analysis of variance (ANOVA) is one of the most widely used methods in statistics to analyze the behavior of one variable compared to another. The data were collected from a sample size of 65 adult males who were nonsmokers, light smokers, or heavy smokers. The aim of this study is to analyze the effects of cigarette smoking on high-density lipoprotein cholesterol (HDL-C) level and determine whether smoking causes a reduction in this level, by using the completely randomized design (CRD) and Kruskal- Wallis method. The results showed that the assumptions of the one- way ANOVA are not satisfied, while, after transforming original data by using log transformation, they are satisfied. From the results, a significantly decreased level of HDL-C in smokers as compared to non-smokers is indicated.