Abstract
Background
Inadequate blood pressure (BP) control is a frequent challenge in general practice. The objective of this study was to determine whether a color-coded BP booklet using a traffic light scheme (red, >180 mmHg systolic BP and/or >110 mmHg diastolic BP; yellow, >140–180 mmHg systolic BP or >90–110 mmHg diastolic BP; green, ≤140 mmHg systolic BP and ≤90 mmHg diastolic BP) improves BP control and adherence with home BP measurement.
Methods
In this two-group, randomized controlled trial, general practitioners recruited adult patients with a BP >140 mmHg systolic and/or >90 mmHg diastolic. Patients in the control group received a standard BP booklet and the intervention group used a color-coded booklet for daily home BP measurement. The main outcomes were changes in BP, BP control (treatment goal <140/90 mmHg), and adherence with home BP measurement after 6 months.
Results
One hundred and twenty-one of 137 included patients qualified for analysis. After 6 months, a significant decrease in systolic and diastolic BP was achieved in both groups, with no significant difference between the groups (16.1/7.9 mmHg in the intervention group versus 13.1/8.6 mmHg in the control group, P=0.3/0.7). BP control (treatment target <140/90 mmHg) was achieved significantly more often in the intervention group (43% versus 25%; P=0.037; number needed to treat of 5). Adherence with home BP measurement overall was high, with a trend in favor of the intervention group (98.6% versus 96.2%; P=0.1)
Conclusion
Color-coded BP self-monitoring significantly improved BP control (number needed to treat of 5, meaning that every fifth patient utilizing color-coded self-monitoring achieved better BP control after 6 months), but no significant between-group difference was observed in BP change. A markedly higher percentage of patients achieved BP values in the normal range. This simple, inexpensive approach of color-coded BP self-monitoring is user-friendly and applicable in primary care, and should be implemented in the care of patients with arterial hypertension.
Acknowledgments
The study is funded by the Swiss Academy of Medical Sciences (approved on 30 April 2011) and Uniscientia Stiftung, Vaduz. BP measurement devices were provided at a reduced price by Melectronics, Zürich, Switzerland. The funding sources had no influence on study design; on the collection, analysis, and interpretation of data; on the writing of the manuscript; or on the decision to submit the manuscript for publication. We are very grateful to Kaba Dalla Lana, Anke Schickel, and Barbara Portmann for their administrative help and to the GPs who recruited and followed patients. We also thank Christian Häuptle from Kantonsspital, St Gallen, for support in recruiting participating GPs.
Author contributions
CC, OS, TR, and CSS developed the study protocol. CC was study investigator and wrote the drafts of the manuscript. CC, OS, and VDP performed statistical analysis and interpreted data. OS and CSS were study investigators and substantially contributed to and reviewed the drafts of the manuscript. CC and VDP were responsible for data collection. All authors revised drafts of the manuscript, read and approved the final manuscript.
Disclosure
CSS has an unrestricted grant from AstraZeneca Switzerland for chronic care and patient education. CSS works on advisory boards and gives talks for AstraZeneca, Novartis, Boehringer Ingelheim, and Merck Sharp and Dome. The other authors have no conflicts of interests to declare.