CMS used a Tukey Outlier Deletion Method (MA) to calculate Medicare Advantage (PDP), star rating. The Final Rule, which was implemented in 2022, eliminated the Tukey outlier deletion form quality measures. Based on 2020 historical data, 17% would have lower star ratings than 1%. We are now left to ask the question: What is a Tukey outlier?
Definitions of Tukey Outlier.
Tukey outliers refer to data points that are outside of the following range.
- {Q1 – k(IQR), Q3+k(IQR)}
Here Q1 is the first quartile and Q3 the third, respectively. IQR is interquartile range. The term K It is a multiplier that indicates how sensitive you would like to outliers. John Tukey suggested that K = 1.5 indicates an “outlier”, and K = 3 indicates data that is “far out”.
What is your probability of identifying an outlier with Tukey?
This question is answered by (i) how wide you Tukey range (i.e., what value) K(iii) The shape of your distribution. Andrey Akinshin created…
