Data mining doctor's patients vs. what compounding pharmacy fills the script or compounding pharmacy vs. the doctor writing the scripts may be critical evidence of fraud, kickbacks and other crimes.

"The defendant referred virtually every patient prescribed topical pain-relief cream to a single pharmacy, Best Aid, which prepared and dispensed the topical pain-relief creams."

https://www.fbi.gov/minneapolis/press-releases/2015/bloomington-pain-management-doctor-indicted-for-accepting-kickbacks-as-part-of-large-scale-health-care-fraud-scheme