Lowering raised blood pressure reduces patients' risk of developing cardiovascular disease.1 2 But the control of hypertension is often suboptimal, and this is borne out by the poorer effectiveness of treatment in observational studies than in randomised clinical trials.3 A recent systematic review by Fahey and colleagues emphasised that effective care for people with hypertension requires rigorous management with regular review and willingness to intensify drug treatment.4

The outcome of regular care depends on patients as much as, or more than, it does on practitioners. Evidence on managing chronic diseases such as diabetes mellitus and asthma emphasises the value of patients' participation, and the same is probably true for self monitoring of blood pressure. Measuring blood pressure is straightforward and has become even more so with the development of validated electronic …