Recently published in The Lancet, the research behind this tool could transform how high blood pressure is managed. It allows doctors to tailor therapy to each patient's needs based on how much they need to reduce their blood pressure.

"This is really important because every 1mmHg reduction in systolic blood pressure lowers your risk of heart attack or stroke by two percent," said Nelson Wang, cardiologist and Research Fellow at The George Institute for Global Health.

"But with dozens of drugs, multiple doses per drug, and most patients needing two or more drugs, there are literally thousands of possible options, and no easy way to work out how effective they are," he said.

Turning Data Into Smarter Treatment Choices

The new calculator addresses this complexity by analyzing average treatment effects across hundreds of studies. It also classifies therapies as low, moderate, or high intensity, depending on how much they reduce blood pressure (BP) -- an approach already used in cholesterol management.

A single blood pressure medication, which is still the standard way most treatments begin, typically lowers systolic BP by only 8-9 mmHg. Many patients, however, need drops of 15-30 mmHg to reach healthy targets.

Dr. Wang explained that although doctors have traditionally adjusted therapy by monitoring each patient's blood pressure readings, those measurements are too variable to depend on alone.

The Problem With "Noisy" Blood Pressure Readings

"Blood pressure changes from moment to moment, day to day and by season -- these random fluctuations can easily be as big or larger than the changes brought about by treatment," he said.

"Also, measurement practices are often not perfect, bringing in an additional source of uncertainty -- this means it's very hard to reliably assess how well a medicine is working just by taking repeated measurements."

Anthony Rodgers, Senior Professorial Fellow at The George Institute for Global Health, noted that while high blood pressure is the most common reason people visit their doctor, there has never been a single, comprehensive source showing how effective different drugs are, particularly when combined or used at different doses.

A New Approach to Managing Hypertension

"Using the calculator challenges the traditional 'start low, go slow, measure and judge' approach to treatment, which comes with the high probability of being misled by BP readings, inertia setting in or the burden on patients being too much," he said.

"With this new method you specify how much you need to lower blood pressure, choose an ideal treatment plan to achieve that based on the evidence, and get the patient started on that ideally sooner rather than later."

The next step will be to test this approach in a clinical trial, where treatments are prescribed according to how much a patient needs to lower their blood pressure, using the calculator as a guide.

A Global Health Challenge

High blood pressure remains one of the world's most serious health threats, affecting an estimated 1.3 billion people and contributing to about ten million deaths every year.¹

Often referred to as a "silent killer" because it produces no obvious symptoms, hypertension can go unnoticed until it leads to heart attack, stroke, or kidney disease. Fewer than one in five people with the condition have it adequately controlled.²

"Given the enormous scale of this challenge, even modest improvements will have a large public health impact -- increasing the percentage of people whose hypertension is under control globally to just 50% could save many millions of lives," Professor Rodgers said.

The Blood Pressure Treatment Efficacy Calculator is freely available at www.bpmodel.org^[1].

Notes

1. Global report on hypertension: the race against a silent killer. Geneva: World Health Organization; 2023. Licence: CC BY-NC-SA 3.0 IGO
2. World Heart Federation. Hypertension. https://world-heart-federation.org/what-we-do/hypertension/^[2]