Guidelines from the British Hypertension Society

Editor—The new guidelines from the British Hypertension Society exemplify the best and the worst features of current medical thought processes.¹,² They exemplify the best in collating evidence from many trials and transforming it into a clear and useful form. They define the problem clearly and positively guide us as doctors, and patients, on future treatment of the defined problem.

Yet they miss some important wider issues. Maybe the omission is deliberate, or maybe the authors are not fully aware of these problems. From a secondary care perspective, seeing patients in admissions wards with strokes due to hypertension, to reduce blood pressure in everyone with hypertension seems to make sense. Yet when viewed from a primary care or public health viewpoint, such a view is far from proved.³

The hypertension guidelines give no information on numbers needed to treat to achieve a reduction in cardiovascular events. Yet the numbers who may need treatment are vast: 42% of those aged 35-64 (about 12 million people).¹ Williams et al also give no information on the figures that matter to patients—namely, their personal probability of benefit⁴ from treatment and the number needed to treat to harm, either by pharmacological side effects or the psychological side effects from having a disease label.

Until these numbers are explicit, I as a primary care doctor cannot know whether in any individual case I am doing more harm or good to my patient in diagnosing hypertension. If I do not know this I cannot give my patient accurate information about treatment, and so I cannot obtain informed consent to, and concordance with, any treatment plan. This lack is a major omission before we decide whether to implement these guidelines and whether they can achieve successful reduction of individual levels of cardiovascular risk.