High blood pressure, also called hypertension, is one of the most common health conditions in the world.
Millions of people have it, and many do not realize it because high blood pressure often causes no symptoms. Even when people feel completely well, the condition can slowly damage the body.
Over time, uncontrolled high blood pressure can injure blood vessels and increase the risk of heart attacks, strokes, heart failure, kidney disease, and dementia.
In the United Kingdom, high blood pressure is linked to about half of all heart attacks and strokes. Because of these serious risks, doctors often prescribe medications to lower blood pressure and reduce the chances of life-threatening complications.
However, taking medication every day is not always easy. Some people forget doses. Others stop taking medicines because of side effects, cost, complicated treatment schedules, or because they do not believe they need treatment since they feel healthy. Doctors call this problem medication nonadherence.
Medication nonadherence is more common than many people realize. Research suggests that up to one in three people with high blood pressure do not take their medicines exactly as prescribed.
This can make blood pressure difficult to control and may lead doctors to order unnecessary tests or prescribe additional medications. It also places a major financial burden on healthcare systems.
To address this problem, researchers from the University of Manchester and Manchester University NHS Foundation Trust carried out the largest U.K. study of a special urine test designed to determine whether patients are taking their blood pressure medications.
The study was called OUTREACH and its findings were published in The Lancet Primary Care.
The test uses a highly sensitive laboratory technique called chemical adherence testing, or CAT. The technology can detect whether blood pressure medications or their breakdown products are present in blood or urine samples.
Doctors sometimes use this method in specialist clinics when they suspect that a patient’s high blood pressure may be related to missed medications.
The researchers wanted to know whether showing patients the results of the test and discussing the reasons behind missed doses could encourage people to take their medicines more regularly.
The study involved 130 adults with hypertension who were taking at least two blood pressure medications. All of them had been identified as not fully following their treatment plans after their urine samples were tested using CAT.
The participants were randomly divided into two groups. One group received the results of their urine test and had a personalized discussion with healthcare professionals about why they were missing doses. The other group continued receiving standard care.
The researchers followed participants for almost three months. They then measured both medication-taking behavior and blood pressure levels.
The results were encouraging in some ways. People who received the urine test results and participated in discussions became more likely to take their prescribed medications properly. This suggests that simply sharing objective information and talking openly about barriers to treatment may motivate people to improve their medication habits.
The blood pressure findings were less clear. On average, people in the intervention group had systolic blood pressure readings that were about 5 millimeters of mercury lower than those in the standard-care group. However, this difference was not large enough to be considered statistically significant.
The researchers believe this may be partly because the study was relatively small and the follow-up period was fairly short. Larger and longer studies may be needed to determine whether improved medication adherence eventually leads to greater reductions in blood pressure.
Professor Maciej Tomaszewski, the study’s chief investigator, said that discussing the test results with patients appeared to improve adherence, even though the study could not demonstrate a definite improvement in blood pressure control.
Professor Bryan Williams from the British Heart Foundation said that helping people take their medicines correctly is essential because high blood pressure remains one of the most important preventable causes of cardiovascular disease.
The study has several strengths. It was the largest randomized trial of its kind in the United Kingdom and used objective laboratory testing rather than relying on patients’ self-reports. The personalized discussions also addressed the real-life reasons why people miss their medications.
However, the study has limitations. The number of participants was relatively small, and the follow-up period lasted only a few months. The findings also cannot tell researchers whether improved adherence can be maintained over many years.
Even so, the study highlights an important idea. Sometimes, helping people manage chronic diseases is not only about creating new drugs. It may also involve better ways of understanding patient behavior and supporting people in following treatments that already work.
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