I was recently at the golf course working with a clubfitter on selecting a driver that was optimal for my game. We went through lots of different clubheads and shafts, hitting each on a very advanced radar system that exactly measures launch characteristics and ballflight. I was struck at how quickly he was moving through different ideas, having me hit each variation only a few times before moving on to something else. Having fit clubs for many tour professionals, the gentleman I was working with clearly knew what he was doing – but at the same time I was struck how little he understood the mathematics of what was going on, and wondered if his advice was really as valid as he thought it was.
When Ortho Evra, the contraceptive patch came on the market, physicians were happy that women had a new and novel contraceptive method that significantly expanded options over what was already available. Since that time, hundreds of thousands of women worldwide have safely used Ortho Evra for birth control.
As the transdermal patch was a new delivery method for birth control, several new pharmacokinetic studies were done postmarketing, in addition to those done prior to FDA approval. One of these studies demonstrated that patients using Ortho Evra had on average 60% higher estrogen blood levels than patients on oral contraceptives, despite lower peak levels (1). Given that estrogen somewhat increases the risk of venous thromboembolism(VTE), this data raised the concern that Ortho Evra might confer a greater attributable risk than traditional oral contraceptives.