Author + information
- Kenneth M. Kessler, MD, FACC* ()
- ↵*University of Miami School of Medicine, C/O 26 William Howard Drive, Glen Mills, PA 19342
The expert panel/writing group presented evidence-based guidelines for cardiovascular disease prevention in women (1). The researchers stated it is appropriate to consider supporting class I recommendations with level-B evidence when there is lack of feasibility of conducting future controlled studies in women. This method of handling incomplete data constitutes a clear departure from a pure evidence-based system wherein the lack of evidence, for whatever reason, weakens the truth value of an issue and should therefore lead to less strong recommendations. Moreover, this new approach is ironic given that the hormone replacement therapy observational data was only found to be incorrect by appropriate controlled trials. Allowing incomplete data to support class I recommendations may give the appearance that further studies are not necessary. One can reasonably argue that, although ethical or practical reasons may exist not to conduct randomized trials, there is rarely a pure scientific reason not to do so. To the contrary, such trials are mandated if cause and effect are to be appropriately assessed. Even if the cited issues regarding cigarette smoking in women arguably justify separate handling of pertinent recommendations, it is not at all clear whether such a move can be justified for the other lifestyle recommendations. I have previously argued (2) that the single hierarchy system currently used to evaluate the evidentiary merit of cardiovascular guideline recommendations may be misleading in the real world, particularly with respect to opinion evidence. The expert panel's (1) current departure from traditional scientific evidence further supports such a revision of the current single hierarchy evidentiary system. If panel members wish to assign a stronger truth value to certain evidence under “justifiable” circumstances they should do so outside the evidence-based single hierarchy system. As such, the statement could be made for ethical reasons without degrading the concept of scientific evidence.
- American College of Cardiology Foundation