I am analyzing the age of a certain group of people and I want to use percentiles and inter-quartile-range in the data to flag possible outliers. I am getting Q1 - 25th percentile, Q3 - 75th percentile, and inter-quartile-range, IQR = Q3 - Q1. Using the convention in analyzing a boxplot, I am going to use Q1 - 1.5IQR and Q3 + 1.5IQR as the threshold for outliers.
My question is: if the age does not follow normal distribution and is skewed, is using percentiles and IQR to detect outliers still meaningful?
If not, what would be a better approach?