Frequently, in research, we look for “proxy measures” of disease – if we can prove that a high blood pressure is associated with mortality, then we can assume that lowering that blood pressure will reduce mortality.
That just ain’t necessarily so – the body is complex, our interventions have side effects and there may be unintended consequences.
CAST – we assumed that treating ventricular dysrhythmia after a heart attack was a good thing…but the treatment was worse than the disease .
Womens’ Health Intiative – we improved cholesterol, bone density and possibly Alzheimer’s with estrogen in post-menopausal women, but not until the better trial was performed did we realize we were causing disease .
So, we, as busy clinicians, should try to find all the Patient-Oriented Evidence we can. By doing so, we can avoid hasty or premature conclusions about how the body and our treatments work.
When faced with Disease-Oriented Evidence, we must use caution in interpreting its results, and look for more Patient-Oriented results (elsewhere in the literature, or in the future from better studies)