I don't know about the blood draw frequency but there are multiple studies addressing the breast cancer 'non-compliance' issue. Because approximately 50% of the women who begin taking aromatase inhibitors quit taking them with 5 years. The estimate is that 75% or so of that 50% actually quit taking them with the first two years. These numbers don't include the woman who are prescribed them but never start taking them. [I've posted links to articles elsewhere here. And anyone can search on Google Scholar for more.]

Also these numbers don't include the women who fill the prescriptions but don't take the drug but don't want their doctors to know.

My point is that there are a lot of women who suffer side effects that just are too difficult to add to their lives for any number of reasons. I hope that everyone who can benefit from them tries them, seriously and for a fair period of time. But I also hope that those who do and find the drugs intolerable know that they are not alone in that place.