Algorithm-based Home Management of High Blood Pressure (a JAMA study)

In a recent JAMA article, researchers investigate whether patients with hypertension can be trained in self-management of their condition.

A primary care, unblinded, randomized clinical trial involving 552 patients who were aged at least 35 years with a history of stroke, coronary heart disease, diabetes, or chronic kidney disease and with baseline blood pressure of at least 130/80 mm Hg being treated at 59 UK primary care practices was conducted between March 2011 and January 2013.

The intervention group used an automated blood pressure device and changed their medications based on individualized self-management algorithms. I would have preferred a blinded study, but I imagine that would be difficult—if not impossible—to manage.

The study found a moderate reduction in systolic blood pressure, in accordance with their primary goal.

After 12 months, the mean blood pressure had decreased to 128.2/73.8 mm Hg in the intervention group and to 137.8/76.3 mm Hg in the control group, a difference of 9.2 mm Hg (95% CI, 5.7-12.7) in systolic and 3.4 mm Hg (95% CI, 1.8-5.0) in diastolic blood pressure following correction for baseline blood pressure.

The intervention group ended with higher doses and number of medications, but that didn’t seem to translate into an increase in adverse effects. There was no difference in quality of life measurements.

Only 1.201 (~16%) of the 7.411 invited patients accepted the invitation. Because of this selection bias, one cannot extrapolate the study to the general public. Also, fewer men than women dropped out of the study, which introduces a gender bias. Since the study mainly included patients who were mostly white, from a professional or skilled manual background, it is easier to generalize the study for the Nordics than for all of UK or the U.S.

One should remember that blood pressure is only a surrogate end-point. The study did not review any hard end-points. Therefore this research paper should only be used to conclude whether self-management of blood pressure leads to a stricter adherence to guidelines—which seems to be the case. Whether this translates into health benefits is difficult to conclude.

The main takeaway from this study is that it is possible for a subgroup of patients to regulate their own blood pressure medication without the need to visit a doctor and still adhere to guidelines. That begs the question: How does this translate into mHealth?