The National Institute for Heath and Clinical Excellence, known as NICE, advises doctors on best practice. Before 2011, NICE told doctors to diagnose high blood pressure by taking repeat measurements of blood pressure during clinic appointments. In 2011, NICE guidance changed and doctors were told to diagnose high blood pressure based on blood pressure measurements taken by patients themselves at home. This change aimed to better target treatment on people most likely to benefit in terms of reducing heart attacks and strokes. However, critics said it would lead to fewer diagnoses and be dangerous to patients. We will study data from GP surgeries and hospitals in England before and after the guidelines change in 2011. We will study how the number of people diagnosed with high blood pressure has changed and whether this has had an effect on the number heart attacks and strokes. We will also look at changes in how blood pressure is measured (at home or during usual appointments), GP workload the number of blood pressure drugs prescribed. Results from this study will show if the change in guidance may have resulted in patient harm and will inform the next update to guidance in 2019.
Background and Aims: in 2011, the National Institute for Health and Care Excellence (NICE) recommended the routine use of ambulatory and home blood pressure monitoring for the diagnosis of hypertension along with changes in recommendations for anti-hypertensives. These changes were predicted to be cost-effective but opponents suggested they would lead to increased cardiovascular morbidity and mortality. We aim to assess the impact of the change in NICE recommendations for the diagnosis and treatment of hypertension on the epidemiology, monitoring, treatment, and primary care workload of hypertension and possible impact on cardiovascular morbidity and mortality. Methods: Clinical Practice Research Datalink (CPRD) with linked Hospital Episode Statistics (HES) and ONS mortality data will be used to assess changes related to the diagnosis of hypertension in the English population from 2006 to 2011 and 2012 to 2017, using an interrupted time series methodology. Changes over time in the incidence of hypertension as coded in the primary care record will be the primary outcome; secondary outcomes will be changes in the use of out-of-office blood pressure monitoring, the prescription of antihypertensive medication, General Practice workload associated with blood pressure monitoring and hypertension, and changes in cardiovascular morbidity and mortality as well as all-cause mortality.
Incidence of hypertension (primary); New prescriptions of antihypertensive medication; Rate of out-of-office blood pressure monitoring; General practice workload associated with hypertension; Incidence of primary cardiovascular events; Cardiovascular mortality; All-cause mortality.
Richard McManus - Chief Investigator - University of Oxford
Sarah Lay-Flurrie - Corresponding Applicant - University of Oxford
Carl Heneghan - Collaborator - University of Oxford
Christian Mallen - Collaborator - Keele University
James Sheppard - Collaborator - University of Oxford
Jonathan Mant - Collaborator - University of Cambridge
Richard Hobbs - Collaborator - University of Oxford
Richard Stevens - Collaborator - University of Oxford
Sarah Lay-Flurrie - Collaborator - University of Oxford
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation