Fibrates: Clinical Outcomes vs Lipid Lowering

All through my undergrad, post-bac, medical school, residency & fellowship days, I never understood just how important statistics would be in the practice of medicine.  Yesterday, I expounded on the general concept of number needed to treat (NNT) while two weeks ago, I wrote about absolute risk reduction (ARR) with regards to the use of rosuvastatin.

On a related front, within family medicine, we've been pushing for evidence-based medicine for a while to focus on POEMs or patient oriented evidence that matters as opposed to DOEs or disease oriented medicine. What's the difference?  POEMs are clinical outcomes, eg prevention of cancer, death, diabetes, heart attack, strokes, etc.  DOEs are physiologic or surrogate markers of health, eg blood pressure, HgbA1c, HDL, LDL, PSA, etc.  Unfortunately, we don't have POEMs to cover all conditions, so we're left with DOEs in many instances.

However, in some situations, we actually have DOEs demonstrating either harm or at best, no benefit, yet we continue to offer said therapeutic option.  Fibrates are an excellent case in point.  As a pharmaceutical class, they've been on the market since 1974, yet we have not been able to demonstrate any clinical outcome benefit in 37 years, despite their perfect against low HDL (good cholesterol) & high triglycerides (TG) by raising HDL & lowering TG.  Moreoever, in 2010, the results of the ACCORD-Lipids study demonstrated no benefit in lowering the rate/risk of fatal cardiovascular events, nonfatal heart attacks & nonfatal strokes in diabetics.

Yet earlier this year, a study published in JAMA demonstrated that US physicians are writing for more & more fibrates compared to our Canadian counterparts.  Lest I be accused of picking only on cardiologists & gastroenterologists, I would like to point out that those of us in primary care are equally to blame for not keeping up with the literature and practicing evidence-based medicine.  And in an editorial published in the current issue of New England Journal of Medicine, the authors, who sit on the FDA's Endocrine & Metabolic Drug Advisory Panel, didn't mince any words, concluding that the addition of fibrates to statins in diabetics solely for the purpose of lowering cardiovascular events has not been proven. 

So regardless of the therapy being offered, make sure you understand the evidence (statistics) behind the desired benefit (NNT), be it clinical outcome (POEMs) or physiologic marker (DOEs).