Chaperones are increasingly recommended for routine use in Western medicine. There are semi official recommendations in both the UK and USA. The AMA has long had this policy.
The rationale for using chaperones is twofold. In theory their primary purpose is to protect, comfort and assist the patient. In reality though, the usual purpose is to protect the physician against claims of sexual assault or harassment.
This article has been chosen for publication on KevinMD, a widely read medical blog.
Addendum 4/26/11 I note with pleasure a just released set of chaperone guidelines from the American Academy of Pediatrics which does allow both for patient choice and same gender chaperones.