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Adherence with blood pressure self-monitoring in women with pregnancy hypertension, and comparisons to clinic readings: A secondary analysis of OPTIMUM-BP

Research output: Contribution to journalArticlepeer-review

Liza Bowen, Louise Pealing, Katherine Tucker, Richard J. McManus, Lucy C. Chappell

Original languageEnglish
Pages (from-to)68-74
Number of pages7
JournalPregnancy Hypertension
PublishedAug 2021

Bibliographical note

Funding Information: This article represents independent research. RM and LC are supported by Research Professorships from the National Institute of Health Research (NIHR-RP-R2-12-015 and RP-2014-05-019 respectively). RM holds a current National Institute for Health Research Programme Grant for Applied Research (RP-PG-0614-20005), on which KM is a co-applicant. RM, LP and KM have received funding from the National Institute for Health Research Applied Research Collaboration Oxford and Thames Valley. LB is supported by an NIHR Academic Clinical Fellowship in Primary Care. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. Funding Information: We would like to thank all those who took part in the trial or supported it. Layla Lavallee at John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust. Zoe Vowles at Guy's and St Thomas? NHS Foundation Trust. Nick Kametas and Polly Kay at King's College Hospital NHS Foundation Trust. David Churchill, Laura Gardiner and Katherine Cheshire at New Cross Hospital. The Royal Wolverhampton NHS Trust. Sue Ziebland from the Department of Primary Care, Oxford University and Marloes Franssen and David Watt from the Oxford Primary Care Clinical Trials Unit. Publisher Copyright: © 2021 The Author(s) Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors


Objectives: To assess adherence to self-monitoring of blood pressure (SMBP), and differences between SMBP and clinic readings, in a self-monitoring intervention for managing pregnancy hypertension. Study design: OPTIMUM-BP was an unmasked randomised controlled clinical trial. 154 women with pregnancy hypertension from four maternity units in England were recruited and randomised to SMBP or usual care. This secondary analysis included 91 women randomised to self-monitoring who provided BP readings. Trial instructions were for daily SMBP. Main outcome measures: Adherence was calculated as proportion of days on which SMBP readings were taken. Proportion of weeks in which at least 4 and at least 2 SMBP readings were taken was also calculated. Mean differences between clinic and SMBP measurements were calculated. Results: Self-monitored BP data were available for 49 women with chronic hypertension and 42 women with gestational hypertension. Median percentage of days with SMBP readings was 77% (IQR 51, 89) in the chronic hypertension group and 85% (IQR 52, 95) in the gestational hypertension group. Adherence did not vary by different socio-demographic groups. Mean difference (95% CI) between clinic and SMBP for systolic BP was 0.99 mmHg (−1.44, 3.41; chronic hypertension) and 3.76 mmHg (0.75, 6.78; gestational hypertension) and for diastolic BP was 3.03 mmHg (0.93, 5.12; chronic hypertension) and 3.27 mmHg (0.56, 5.98; gestational hypertension). Conclusions: Adherence to self-monitoring was good and differences between SMBP and clinic readings were small. These findings offer reassurance about the use of self-monitoring at a time when it is being increasingly implemented in maternity settings.

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