SNAP-HT: Self-management of raised blood pressure in women after childbirth
The aims of this study were to find out whether home blood pressure monitoring, and self-adjustment of blood pressure medications according to an individualised protocol, can improve blood pressure control and patient satisfaction in women who have developed new-onset raised blood pressure during pregnancy.
Why this is important:
New-onset raised blood pressure affects about one in ten pregnancies. For some women, raised blood pressure is an indication of pre-eclampsia: newly arising high blood pressure in pregnancy combined with protein leaking into the urine. After birth, women’s blood pressure remains elevated for a period of time, but in most cases returns to normal over 2–12 weeks. During this period medication needs to be adjusted to achieve the correct blood pressure control. Research suggests that more normal blood pressure during this period is associated with improved long-term health outcomes.
Self-management approaches may help to empower patients, improve blood pressure control and patient satisfaction, and reduce the burden on primary care and community care services. - Dr Alexandra Cairns, University of Oxford.
National guidance from the National Institute for Health and Care Excellence (NICE) highlights that very few clinical studies have addressed the management of blood pressure after birth. Clinical care is typically to continue the blood pressure medication started during pregnancy and monitor blood pressure in the community with a focus on prevention of over-treatment.
To date research in self-monitoring and self-management of hypertension in non-pregnant patients has shown that it is feasible, acceptable to patients and produces better blood pressure control when compared with conventional monitoring in a clinic setting. Women with new-onset raised blood pressure in pregnancy would seem to be an ideal group in whom to apply this work: the condition has, in general, a limited time course meaning that intensive monitoring is more reasonable. Pregnant women are by definition in a younger age group than the majority of those with chronic hypertension, and may be more comfortable with the use of technology to assist in disease monitoring.
This pilot study was set up to inform the planning of a large-scale multi-centre randomised controlled trial by testing whether our protocol works. We wanted to:
- increase our experience of applying this management approach in this group of patients
- select the most appropriate primary outcome measure and to estimate how well this intervention works
- assess whether women are happy to participate in this type of trial
- evaluate how straightforward it is to coordinate this trial across several centres.
Women recruited to the study were randomly assigned to one of two groups: self-management or usual care. Participants allocated to ‘usual care’ had their blood pressure monitored and medication adjusted by their GP and midwife as normal. Participants allocated to the ‘self-management’ group used a home blood pressure monitor daily following discharge from hospital after birth. They were provided with an individualised schedule for gradually decreasing their medication(s) in line with their blood pressure readings. This was supported through the use of a specially designed website, smartphone app and free text-messaging service. Women were followed up for 6 months.
Patients were involved in the design of the participant information sheet, and in decisions about the consent process for the study. We also surveyed the use of mobile phones and smartphones amongst pregnant women in order to assist us in planning what technologies to use to support self-management.
How this could benefit patients:
In the long-term we hope that self-management approaches may help to empower patients, improve blood pressure control and patient satisfaction, and reduce the burden on primary care and community care services.
Research participants may benefit from greater support regarding their blood pressure care after discharge from hospital following birth. We hope that all participants in the trial will achieve as good, or better blood pressure control. Women in the self-management arm may benefit from needing to schedule fewer GP and midwife appointments in the period immediately following discharge from hospital. However, we will ensure that women who need additional GP or midwife support for other medical, psychological or social reasons continue to receive this.
The results of this study have now been utilised in the planning of a large scale randomised controlled trial to investigate self-management of BP in the postpartum period. Read the paper
Recruitment has commenced in April 2015 at 4 of the 5 research sites. The intention is to recruit 100 women over a 9-month period.