I read on another forum a while back as the reason being that Thrush is less likely over age of 60 so needs checking. I have been a lifelong sufferer of thrush, after every prescription for antibiotics, so certainly know what it is. I am 58 but shall be knocking a few years off of that in the future then. I don't want to have to go and derobe for GP and anyway takes over two weeks to get an in person appointment at our surgery, if you are lucky!