My last article demonstrated a common incorrect technique—based in “traditional” statistics—for comparing performances based on percentage rates. This article will use the same data to show what should be done instead.

To quickly review the scenario: In an effort to reduce unnecessary expensive prescriptions, a pharmacy administrator developed a proposal to monitor and compare individual physicians’ tendencies to prescribe the most expensive drug within a class. Data were obtained for a peer group of 51 physicians including the total number of prescriptions written, and, of that number, how many were for the target drug.

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