ABSTRACT
There are many advantages to using quantiles in biomedical research. Quantiles, particularly very high ones, provide the relevant information regarding ranges of the outcomes. Investigation into outcome ranges is important in the context of the reference ranges of biomarkers, which provide criteria for classifying the normal and abnormal groups. This chapter discusses the quantile estimation using the empirical likelihood (EL) in one-group setting first. The Bahadur representation of the maximum EL estimator (MELE) of the quantile function is presented. Then, it discusses the comparison of quantiles between two groups. Testing methods consist of the conventional EL method and the plug-in method. Relevant R codes are provided for practitioners.
