My new favourite quote comes from a recent paper by Alberto Zanchetti , Guido Grassi and Giuseppe Mancia in the May 2009 Journal of Hypertension.
…[W]isdom should not be taken for evidence…
The paper’s full abstract:
The evidence for two recommendations of all major guidelines on hypertension is critically discussed. The first recommendation is that of initiating antihypertensive drug treatment when systolic blood pressure is at least 140 or diastolic blood pressure at least 90mmHg in patients with grade 1 hypertension and low or moderate total cardiovascular risk, and even when blood pressure is in the high normal range in patients with diabetes and previous cardiovascular disease. The second recommendation is that of achieving systolic blood pressure levels below 140mmHg in all hypertensive patients, including the elderly, and values below 130mmHg in patients having diabetes and high/very-high-risk patients. Critical analyses of the results of available trials show that the evidence is scanty for both recommendations. Nonetheless, they can be accepted as prudent statements, as antihypertensive agents are very well tolerated and lowering systolic blood pressure below 130mmHg appears well tolerated. However, wisdom should not be taken for evidence, and simple trials should be designed to look for more solid evidence in favour of current recommendations.