Which of the following studies represents an example of “real world evidence”?
A. A phase I trial of a new drug examining dosing and safety in healthy volunteers
B. A retrospective cohort study examining antibiotic utilization and patient outcomes based on electronic health record data
C. A randomized, placebo controlled, double blinded phase III clinical trial examining efficacy of a new drug
D. A randomized, double-blind phase III drug trial examining the safety and efficacy of a new drug compared to an active comparator