574 – Interesting Implementations of Network Sampling and Bayesian Regression
A Large Sample Statistical Test for Equality of Percentile Profiles Across Multiple Populations
Lei Zhang
Mississippi State Department of Health
Robbie Beyl
Pennington Biomedical Research Center
Jeff Burton
Pennington Biomedical Research Center
Callie Johnson
Hongmei Han
Pennington Biomedical Research Center
William D. Johnson
Pennington Biomedical Research Center
In large sample studies where distributions may be skewed and not readily transformed to symmetry, it may be of greater interest to compare different distributions in terms of percentiles rather than means. For example, it may be more informative to compare two or more populations with respect to their within population body mass index (BMI) distributions by testing the hypothesis that their corresponding respective 90th percentiles for BMI are equal. The test statistic is asymptotically distributed as Chi-square with degrees of freedom dependent upon the number of percentiles tested and constraints of the null hypothesis. Results are presented from a simulation study of the empirical probability of Type I errors and the empirical power of the test under various alternative underlying parameter values. Numerical examples are provided to illustrate applications.