High blood pressure (BP), a condition called hypertension, leads to more deaths than any health risk except age. Despite the best NHS efforts, only half of people who started on BP-lowering drugs have BP controlled a year later. One reason for poor BP control is that most people with hypertension need several BP-lowering drugs, but the current practice is to start with a low dose of one drug, gradually increasing the dose, and adding more drugs. This causes delays while waiting for the treatment responses, arranging BP monitoring, and repeating blood tests, which can be frustrating and puts people at high risk of never reaching the target.
We recently proposed a study to assess if starting and, if necessary, adding BP-lowering treatments at full doses in younger patients (aged 40-59) helps to achieve BP control sooner and safely. The study intends to compare the proposed full-dose approach to the current starting low-dose drugs with a gradual dose increase.
To develop the study and justify the scale of possible benefits we aim to use CPRD data (feasibility analysis). We will count the number of patients who start their first treatment of hypertension and may be suitable for the future study. We will analyse what happens with their BP management in current practice, including need to repeatedly monitor BP, do blood tests, side effects, and response to different doses of BP-lowering drugs. We will use this information to design the future testing of the proposed new way of starting their treatment.
We plan a grant application for a randomised controlled trial (RCT) to establish if starting pressure (BP)-lowering drugs using full recommended doses compared to the usual starting doses accelerates hypertension control in younger adults and is cost-effective. Following our initial proposal submission, the funder indicated that further information is needed to support the proposal justification.
This feasibility analysis aims to obtain data needed to support the RCT justification and design. It will describe the number of younger patients with new hypertension who are started on BP-lowering drugs and their hypertension management journey over the first 12 months.
The objectives of the feasibility study are:
- Establish the counts of the affected population who will be eligible for the RCT
- Describe the patient's journey over 12 months after starting BP-lowering medications, including follow-up BP measurements, monitoring of renal function, adverse reactions, and achieving BP targets.
- Describe changes in BP-lowering drugs
- Describe BP response to different doses of BP-lowering drugs
The feasibility analyses will be done using Clinical Practice Research Datalink (CPRD) Aurum database. The database is based on electronic health records of the most popular primary care system, called EMIS. The study team uses EMIS in clinical practice and will use it for future patient recruitment. High-quality data extraction is achievable from routine clinical codes, based on Quality and Outcomes Framework metrics and maintained at high standards in general practice.
The study population will consist of patients aged 40-59 years who have recently been diagnosed with hypertension and have just started their first BP-lowering treatment. Exclusion criteria list clinical conditions where initiating full-dose treatment may pose safety risks.
Analysis will include metrics of BP monitoring, safety monitoring (renal function), adverse reactions, timing of BP-lowering drug changes and BP responses to those changes to produce descriptive statistics (R software).
Outcomes will be measured over 12 month after starting first BP-lowering treatment: Number of BP measurements; Number of changes of BP-lowering medications (dose change, stopping medication, starting new medication); BP response to different doses of BP-lowering medications; Number of measurements of renal function; Latest BP values at 12 weeks, 6 months and 12 months after starting BP-lowering treatment; Proportion of patients achieving target BP at 12 weeks, 6 months and 12 months after starting BP-lowering treatment; Worsening renal function; Out of range blood potassium levels.
Eduard Shantsila - Chief Investigator - University of Liverpool
Eduard Shantsila - Corresponding Applicant - University of Liverpool
Chris Kypridemos - Collaborator - University of Liverpool
Gregory Lip - Collaborator - University of Liverpool
Iain Buchan - Collaborator - University of Liverpool
Paul Leeson - Collaborator - University of Oxford
Pieta Schofield - Collaborator - University of Liverpool
CPRD Aurum Ethnicity Record