The motivation for this comparison of approaches to
sample size estimation for paired binary data came from
a study examining how patient gender affected physicians’
treatment recommendations regarding total knee arthroplasty
(TKA) [16]. Specifically, two standardized patients
(one man and one woman) differing only in gender with
otherwise identical case histories underwent blinded assessments
by family physicians and orthopedic surgeons
located in Ontario, Canada. Both standardized patients presented
with chronic knee pain as their chief complaint and
level of function, pain, and prior treatment appropriate for a
patient with moderate knee osteoarthritis. At the end of the
visit, standardized patients recorded the binary primary
outcome: the physicians’ recommendations for TKA
(yes 5 1 and no 5 0) on a postvisit checklist.