Initiation and follow-up of treatment for high blood pressureBMJ 2015; 350 doi: https://doi.org/10.1136/bmj.h167 (Published 05 February 2015) Cite this as: BMJ 2015;350:h167
- Jonathan Mant, professor1,
- Richard J McManus, professor2
- 1Primary Care Unit, Department of Public Health and Primary Care, University of Cambridge, Strangeways Research Laboratory, Cambridge CB1 8RN, UK
- 2Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, OX2 6GG, UK
- Correspondence to: J Mant
High blood pressure is the leading risk factor for disease worldwide.1 Whereas strong evidence from randomised controlled trials is available for some aspects of the management of hypertension, uncertainties remain for others. In the linked article by Xu and colleagues (doi:10.1136/bmj.h158), three of these uncertainties are investigated.2 At what blood pressure threshold should treatment be intensified? How long after a high blood pressure is recorded should treatment be changed? And how long after treatment has been increased should the blood pressure be measured again?
Xu and colleagues used a large electronic database of primary care records from the United Kingdom—The Health Improvement Network (THIN) database—to construct a retrospective cohort of adults with a diagnosis of hypertension. For each patient, they split the data that they had into three time periods: a run-in period of at least 12 months to define baseline characteristics, a treatment period of 10 years from which the three key parameters (intensification threshold, time to intensification, and time to follow-up after intensification) were estimated, and an outcome assessment period. The third period continued until an outcome event had occurred (a cardiovascular event or …