Blood pressure self-monitoring in pregnancy: examining feasibility in a prospective cohort study.

BACKGROUND: Raised blood pressure (BP) affects approximately 10% of pregnancies worldwide, and a high proportion of affected women develop pre-eclampsia. This study aimed to evaluate the feasibility of self-monitoring of BP in pregnancy in women at higher risk of pre-eclampsia. METHODS: This prospective cohort study of self-monitoring BP in pregnancy was carried out in two hospital trusts in Birmingham and Oxford and thirteen primary care practices in Oxfordshire. Eligible women were those defined by the UK National Institute for Health and Care Excellence (NICE) guidelines as at higher risk of pre-eclampsia. A total of 201 participants were recruited between 12 and 16 weeks of pregnancy and were asked to take two BP readings twice daily three times a week through their pregnancy. Primary outcomes were recruitment, retention and persistence of self-monitoring. Study recruitment and retention were analysed with descriptive statistics. Survival analysis was used to evaluate the persistence of self-monitoring and the performance of self-monitoring in the early detection of gestational hypertension, compared to clinic BP monitoring. Secondary outcomes were the mean clinic and self-monitored BP readings and the performance of self-monitoring in the detection of gestational hypertension and pre-eclampsia compared to clinic BP. RESULTS: Of 201 women recruited, 161 (80%) remained in the study at 36 weeks or to the end of their pregnancy, 162 (81%) provided any home readings suitable for analysis, 148 (74%) continued to self-monitor at 20 weeks and 107 (66%) at 36 weeks. Self-monitored readings were similar in value to contemporaneous matched clinic readings for both systolic and diastolic BP. Of the 23 who developed gestational hypertension or pre-eclampsia and self-monitored, 9 (39%) had a raised home BP prior to a raised clinic BP. CONCLUSIONS: Self-monitoring of BP in pregnancy is feasible and has potential to be useful in the early detection of gestational hypertensive disorders but maintaining self-monitoring throughout pregnancy requires support and probably enhanced training.

Blood pressure self-monitoring in pregnancy (BuMP) feasibility study; a qualitative analysis of women's experiences of self-monitoring.

BACKGROUND: Hypertensive disorders in pregnancy are a leading cause of maternal and fetal morbidity worldwide. Raised blood pressure (BP) affects 10% of pregnancies worldwide, of which almost half develop pre-eclampsia. The proportion of pregnant women who have risk factors for pre-eclampsia (such as pre-existing hypertension, obesity and advanced maternal age) is increasing. Pre-eclampsia can manifest itself before women experience symptoms and can develop between antenatal visits. Incentives to improve early detection of gestational hypertensive disorders are therefore strong and self-monitoring of blood pressure (SMBP) in pregnancy might be one means to achieve this, whilst improving women's involvement in antenatal care. The Blood Pressure Self-Monitoring in Pregnancy (BuMP) study aimed to evaluate the feasibility and acceptability of SMBP in pregnancy. METHODS: To understand women's experiences of SMBP during pregnancy, we undertook a qualitative study embedded within the BuMP observational feasibility study. Women who were at higher risk of developing hypertension and/or pre-eclampsia were invited to take part in a study using SMBP and also invited to take part in an interview. Semi-structured interviews were conducted at the women's homes in Oxfordshire and Birmingham with women who were self-monitoring their BP as part of the BuMP feasibility study in 2014. Interviews were conducted by a qualitative researcher and transcribed verbatim. A framework approach was used for analysis. RESULTS: Fifteen women agreed to be interviewed. Respondents reported general willingness to engage with monitoring their own BP, feeling that it could reduce anxiety around their health during pregnancy, particularly if they had previous experience of raised BP or pre-eclampsia. They felt able to incorporate self-monitoring into their weekly routines, although this was harder post-partum. Self-monitoring of BP made them more aware of the risks of hypertension and pre-eclampsia in pregnancy. Feelings of reassurance and empowerment were commonly reported by the women in our sample. CONCLUSIONS: SMBP in pregnancy was both acceptable and feasible to women in this small pilot study.

Accuracy of blood-pressure monitors owned by patients with hypertension (ACCU-RATE study): a cross-sectional, observational study in central England.

BACKGROUND: Home blood-pressure (BP) monitoring is recommended in guidelines and is increasingly popular with patients and health professionals, but the accuracy of patients' own monitors in real-world use is not known. AIM: To assess the accuracy of home BP monitors used by people with hypertension, and to investigate factors affecting accuracy. DESIGN AND SETTING: Cross-sectional, observational study in urban and suburban settings in central England. METHOD: Patients (n = 6891) on the hypertension register at seven practices in the West Midlands, England, were surveyed to ascertain whether they owned a BP monitor and wanted it tested. Monitor accuracy was compared with a calibrated reference device at 50 mmHg intervals between 0-280/300 mmHg (static pressure test); a difference from the reference monitor of +/-3 mmHg at any interval was considered a failure. Cuff performance was also assessed. Results were analysed by frequency of use, length of time in service, make and model, monitor validation status, purchase price, and any previous testing. RESULTS: In total, 251 (76%, 95% confidence interval [95% CI] = 71 to 80%) of 331 tested devices passed all tests (monitors and cuffs), and 86% (CI] = 82 to 90%) passed the static pressure test; deficiencies were, primarily, because of monitors overestimating BP. A total of 40% of testable monitors were not validated. The pass rate on the static pressure test was greater in validated monitors (96%, 95% CI = 94 to 98%) versus unvalidated monitors (64%, 95% CI = 58 to 69%), those retailing for >£10 (90%, 95% CI = 86 to 94%), those retailing for ≤£10 (66%, 95% CI = 51 to 80%), those in use for ≤4 years (95%, 95% CI = 91 to 98%), and those in use for >4 years (74%, 95% CI = 67 to 82%). All in all, 12% of cuffs failed. CONCLUSION: Patients' own BP monitor failure rate was similar to that demonstrated in studies performed in professional settings, although cuff failure was more frequent. Clinicians can be confident of the accuracy of patients' own BP monitors if the devices are validated and ≤4 years old.

Schedules for Self-monitoring Blood Pressure: A Systematic Review.

BACKGROUND: Self-monitoring of blood pressure better predicts prognosis than clinic measurement, is popular with patients, and endorsed in hypertension guidelines. However, there is uncertainty over the optimal self-monitoring schedule. We therefore aimed to determine the optimum schedule to predict future cardiovascular events and determine "true" underlying blood pressure. METHODS: Six electronic databases were searched from November 2009 (updating a National Institute for Health and Care Excellence [NICE] systematic review) to April 2017. Studies that compared aspects of self-monitoring schedules to either prognosis or reliability/reproducibility in hypertensive adults were included. Data on study and population characteristics, self-monitoring regime, and outcomes were extracted by 2 reviewers independently. RESULTS: From 5,164 unique articles identified, 25 met the inclusion criteria. Twelve studies were included from the original NICE review, making a total of 37 studies. Increasing the number of days of measurement improved prognostic power: 72%-91% of the theoretical maximum predictive value (asymptotic maximum hazard ratio) was reached by 3 days and 86%-96% by 7 days. Increasing beyond 3 days of measurement did not result in better correlation with ambulatory monitoring. There was no convincing evidence that the timing or number of readings per day had an effect, or that ignoring the first day's measurement was necessary. CONCLUSIONS: Home blood pressure should be measured for 3 days, increased to 7 only when mean blood pressure is close to a diagnostic or treatment threshold. Other aspects of a monitoring schedule can be flexible to facilitate patient uptake of and adherence with self-monitoring.

Patients' and clinicians' views on the optimum schedules for self-monitoring of blood pressure: a qualitative focus group and interview study.

BACKGROUND: Self-monitoring of blood pressure is common but guidance on how it should be carried out varies and it is currently unclear how such guidance is viewed. AIM: To explore patients' and healthcare professionals' (HCPs) views and experiences of the use of different self-monitoring regimens to determine what is acceptable and feasible, and to inform future recommendations. DESIGN AND SETTING: Thirteen focus groups and four HCP interviews were held, with a total of 66 participants (41 patients and 25 HCPs) from primary and secondary care with and without experience of self-monitoring. METHOD: Standard and shortened self-monitoring protocols were both considered. Focus groups and interviews were recorded, transcribed verbatim, and analysed using the constant comparative method. RESULTS: Patients generally supported structured schedules but with sufficient flexibility to allow adaptation to individual routine. They preferred a shorter (3-day) schedule to longer (7-day) regimens. Although HCPs could describe benefits for patients of using a schedule, they were reluctant to recommend a specific schedule. Concerns surrounded the use of different schedules for diagnosis and subsequent monitoring. Appropriate education was seen as vital by all participants to enable a self-monitoring schedule to be followed at home. CONCLUSION: There is not a 'one size fits all approach' to developing the optimum protocol from the perspective of users and those implementing it. An approach whereby patients are asked to complete the minimum number of readings required for accurate blood pressure estimation in a flexible manner seems most likely to succeed. Informative advice and guidance should incorporate such flexibility for patients and professionals alike.

The use of ambulatory blood pressure measurement.

Measurement of ambulatory blood pressure is recommended by the National Institute for Health and Care Excellence guidelines to confirm the diagnosis of hypertension in the UK. This article describes the use of ambulatory devices, and discusses the benefits and disadvantages of their use in clinical practice.

Is self monitoring of blood pressure in pregnancy safe and effective?

Guidelines encourage the use of self monitoring of blood pressure in pregnancy, and research suggests that women prefer it. But HODGKINSON AND COLLEAGUES: explain that our enthusiasm may run ahead of the evidence and call for more research before it is routinely adopted.

Accuracy of ambulatory blood pressure monitors: a systematic review of validation studies.

BACKGROUND: Recent research and guidelines recommend the routine use of ambulatory blood pressure monitoring for the diagnosis of hypertension, so accuracy of such monitors is more important than ever. AIM: : To systematically review the literature regarding the accuracy of ambulatory monitors currently in use. METHODS: Medline, Embase, Cinahl, the Cochrane database, Medion and the dabl Educational Trust website were searched until February 2011. No language or publication date limits were applied. Data were extracted separately by two independent reviewers. Methodological quality was assessed by whether a validation protocol had been used and followed correctly. RESULTS: From 5420 journal articles identified, 108 met the inclusion criteria. Excluding studies assessing monitors no longer in use, 40 relevant studies were found using 21 different monitors. Thirty-eight (95%) studies used a validation protocol of which 28 studies assessed a monitor in the general population. Of these, protocols were passed in 24 of 28 studies, but 12 of 24 (50%) found a difference of at least 5 mmHg systolic between the test device and the reference standard for 30% or more of the readings. Of the 10 studies conducted in special population groups (e.g. pregnancy, elderly people), only four devices passed the protocols. Only six (16%) studies correctly adhered to the protocols. CONCLUSION: Published validation studies assessed most ambulatory monitors as accurate, but many failed to adhere to the underlying protocols, undermining this conclusion and peer review standards. Furthermore, most monitors which 'passed' validation showed significant variation in blood pressure from the reference standard, highlighting inadequacies in older validation protocols. Future validation studies should use protocols with simpler methodologies but more rigorous accuracy criteria.

Predictors of incident atrial fibrillation and influence of medications: a retrospective case-control study.

BACKGROUND: Atrial fibrillation (AF) is a common condition, associated with raised mortality and risk of major morbidity, and is predicted to increase due to an aging population. AIM: To update earlier research of AF predictors using UK data. DESIGN AND SETTING: Case-control analysis of adults aged 18 years and older with a diagnosis of AF in practices registered with the General Practice Research Database (GPRD) in the UK. METHOD: Using the GPRD, a case.control analysis was performed using logistic regression to compare 55,412 incident AF cases to 216,400 controls, for medical history and prior use of drugs. The association between time since start of diagnosis or drug use and AF risk was summarised using Spline regression. RESULTS: The following were confirmed as risk factors for AF: heart failure (risk ratio [RR] 2.91 [95% CI = 2.59 to 3.27]); ischaemic heart disease (IHD) (RR 2.00 [95% CI = 1.78 to 2.24]); hypertension (RR 2.60 [95% CI = 2.32 to 2.92]); hyperthyroidism (RR 1.56 [95% CI = 1.39 to 1.75]); being a heavy drinker (RR 1.43 [95% CI = 1.27 to 1.60]); cerebrovascular accident (RR 1.48 [95% CI = 1.32 to 1.66]); and obesity (body mass index ≥30 kg/m(2) RR 1.29 [95% CI = 1.15 to 1.45]). Current use of oral glucocorticoids (RR 1.62 [95% CI = 1.44 to 1.82]) and of beta-2 agonists (RR 1.30 [95% CI = 1.16 to 1.46]) were identified as significant risk factors, and statins (RR 0.82 [95% CI = 0.73 to 0.92]) as a significant protective factor. No effect was found for current use of bisphosphonates (RR 0.95 [95% CI = 0.85 to 1.07]), renin.angiotensin.aldosterone system (RAAS) agents (RR 1.04 [95% CI = 0.93 to 1.17]), or xanthine derivatives (RR 1.09 [95% CI = 0.97 to 1.22]). Spline regression analysis found the effect of heart failure, IHD, use of oral glucocorticoids, and use of statins on the likelihood of developing AF was sustained over a number of years. CONCLUSION: These findings update the risk factors that are associated with AF, and confirm the protective properties of statins and the risks of beta-2 agonists in developing AF, but not the supposed protective qualities of glucocorticoids and RAAS agents.