A large UK study compared the effectiveness of self-monitoring blood pressure with clinic monitoring for adjusting treatment to control high blood pressure.
High blood pressure is an important risk factor for cardiovascular disease. Antihypertensive drugs are used to lower blood pressure and reduce cardiovascular disease risk. However, tailoring the appropriate drug treatment for each patient can be a time-consuming and difficult process. In many cases, blood pressure cannot be optimally controlled. Usual care often involves repeated clinic visits for blood pressure measurements and adjusting the doses for antihypertensive medications.
Self-monitoring blood pressure has had mixed results in the past
Studies examining the efficacy of patients self-monitoring their blood pressure to help with treatment adjustment have had mixed results. A large study in the United Kingdom (UK) compared the effects of patients self-monitoring their blood pressure, with or without telemonitoring support, and usual clinical care in primary care practices. The results were recently reported in The Lancet.
The study included over 1000 patients from 142 primary care practices around the UK. The patients had blood pressures over 140/90 mmHg and were not well-controlled by the usual clinic readings. All patients were willing to self-monitor their blood pressure and were randomly assigned to one of three groups: self-monitoring, self-monitoring with telemonitoring, or usual care (control group).
Assessing effects on blood pressure in three different groups
The two self-monitoring groups were taught how to use an electronic blood pressure reader and were asked to record their blood pressure twice each morning and evening for the first week of every month.
Those in the self-monitoring only group sent a paper record of the readings to their general practitioner by mail. They were given simple training about blood pressure readings and asked to visit their clinic if the readings were very high or very low.
Those in the telemonitoring group sent their readings via an SMS text-based service. This service included alerts prompting patients to send readings and asking them to attend clinic if they reported very high, very low or above target readings. They sent readings to a web-based interface for review by primary care physicians. A graphical display of the blood-pressure readings highlighted very high or very low readings and calculated mean blood pressure for the week.
Patients in the usual care group attended the clinic for blood pressure readings as requested by their general practitioner. The physicians reviewed the two self-monitoring groups readings on a monthly basis and usual care patients as often as they wished. The physicians were free to adjust antihypertensive medications in all three groups at their own discretion, guided by blood pressure readings. The research group reviewed all patients at 6 months and 12 months to compare the blood pressures achieved in each group.
Blood pressure was lower in both self-monitoring groups
After 12 months, the blood pressure was significantly lower in both self-monitoring groups compared with usual care. At that time, there was no significant difference in blood pressure between self-monitoring alone and self-monitoring with telemonitoring groups. However, the blood pressure in the telemonitoring group became lower more quickly (by the 6-month check) than in the self-monitoring alone group.
The researchers concluded that self-monitoring, with or without telemonitoring, when used by primary care physicians to adjust antihypertensive treatment, led to a significantly lower blood pressure than adjustment guided by clinic measurements alone.
It is estimated that around 30% of hypertensive patients in the UK and elsewhere already use blood pressure self-monitoring. Self-monitoring could become a useful tool for improving hypertension management in the primary care setting.
Written by Julie McShane, Medical Writer
Reference: McManus RJ, Mant J, Franssen M, et al. Efficacy of self-monitored blood pressure, with or without telemonitoring, for titration of antihypertensive medication (TASMINH4): an unmasked randomized controlled trial. Lancet 2018;391:949-59.doi:10.1016/S0140-6736(18)30309-X