Around a third of adults in the UK have high blood pressure, although many will not realise it. Persistent high blood pressure can increase the risk of a number of serious and potentially life-threatening health conditions, such as heart disease and stroke. Hypertension is readily treatable, yet many people who are seen in health systems with high blood pressure do not receive adequate treatment, support, or assistance to control their blood pressure.
To identify opportunities to improve care for patients, we want to use electronic health record data to look at patterns of follow-up care for people who have a high blood pressure reading taken at the GP. Our focus is on people with markedly elevated blood pressure readings (above 160/100 mm Hg) since this has the most serious ramifications.
Specifically, we will describe: 1) how often these patients have timely subsequent visits, and 2) how commonly they ultimately achieve guideline-based blood pressure control targets. We also want to understand how a patient’s social, demographic and clinical background affects their follow-up care.
The goal is to determine the extent of opportunity to improve care by focusing on patients in the health system who may be ‘falling through the cracks’ by not having their high blood pressure adequately managed.
This study is an extension of a recent US study that retrospectively analysed data on adult patients in the Yale-New Haven Health System.1 The aim is to adapt this study design for an English context and use CPRD Aurum to identify patients with markedly elevated blood pressure and characterise their follow-up care pattern. The authors of the original study are collaborators on this project.
This is an observational follow-up study of a random sample of adults aged under 80 with at least one markedly elevated blood pressure reading recorded during the study period (January 2015 to March 2020). Using an open cohort design, we will identify and follow-up two groups of patients: Group 1 - patients with at least 1 systolic blood pressure (SBP) ≥160 mm Hg or diastolic blood pressure (DBP) ≥100 mm Hg and Group 2 - patients with at least 1 systolic blood pressure (SBP) ≥180 mm Hg or diastolic blood pressure (DBP) ≥120 mm Hg (a subset of group 1 patients with a more extreme phenotype).
For each group, we will describe: 1) how often these patients have timely subsequent visits (within 1, 3 and 6 months), and 2) how commonly they ultimately achieve guideline-based blood pressure control targets (within 3, 6 or 12 months). We will also describe the median duration between the first measurement of elevated blood pressure and 1) a follow-up visit and 2) achievement of control target. A focus of the analysis will be to examine how these indicators vary by patients’ socio-economic characteristics (age, sex, geographic region, ethnicity and deprivation) and clinical factors (BMI, smoking status, hypertension diagnosis, selected comorbidities).
Primary outcome:
Number and percentage of patients who had at least 1 markedly elevated reading of systolic blood pressure [SBP] ≥160 mm Hg or diastolic blood pressure [DBP] ≥100 mm Hg who have a subsequent blood pressure reading recorded within 1, 3, 6 or 12 months (overall and in subgroups of age, sex, IMD quintile, geographic region and ethnicity). A sub-group analysis will be performed out with a subset of patients with a more extreme phenotype (SBP ≥180 mm Hg or DBP ≥120 mm Hg).
Secondary outcomes (overall and in subgroups of age, sex, IMD quintile, geographic region and ethnicity):
Number and percentage of patients who reach BP control target (recorded SBP <140 mm Hg and DBP <90 mm Hg) within 3,
6 or 12 months.
Median durations between the first measurement of elevated blood pressure and follow-up visit
Median duration between the first measurement of elevated blood pressure and control target achievement.
The number of markedly elevated SBP or DBP measurements during the study period (adjusted for length of follow-up)
Hannah Knight - Chief Investigator - The Health Foundation
Yannis Kotrotsios - Corresponding Applicant - The Health Foundation
Anne Alarilla - Collaborator - The Health Foundation
Caroline Fraser - Collaborator - The Health Foundation
Jay Hughes - Collaborator - The Health Foundation
Mai Stafford - Collaborator - The Health Foundation
Thomas Prendergast - Collaborator - The Health Foundation
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation Domains