The diagnosis of hypertension may be off the mark if doctors go by the results of just one blood pressure test, a study conducted across 15 states found, with 24 per cent of people getting wrongly diagnosed as hypertensive.
Additionally, 18 per cent people who did have hypertension were not correctly diagnosed, the study stated.
With the study, which included 1,233 doctors, it was suggested that at least three blood pressure tests over an interval of two minutes are required to confirm hypertension. An alternative is to conduct home-based tests during which the patient is relaxed and accurate blood pressure (BP) can be noted.
Conducted by Eris Lifesciences, a pharmaceutical company headquartered in Ahmedabad, the study included 18,918 people aged between 18 and 75 years, across 355 cities. The normal blood pressure range was considered to be below 140 and above 90.
White coat hypertension is a condition due to which patients have increased blood pressure when they visit a doctor — but they are not otherwise hypertensive.
“This happens a lot if a person visits a hospital for the first time or has stress while undergoing a test. The BP reading is found to be high. Readings at home will show normal blood pressure,” said Dr C K Ponde, a cardiologist at Hinduja hospital. In such cases, people may be prescribed hypertension medications even if they do not require it.
The contrast condition is masked hypertension, where a patient is hypertensive, but it does not immediately get diagnosed during the first BP reading.
“What is worrying is masked hypertension. Since these patients are not aware of their condition, they can suffer from heart problems and kidney ailment if the treatment does not start on time,” said cardiologist Brian Pinto, from Holy Family hospital, Bandra.
In Mumbai, where 1,643 people were evaluated, 15.4 per cent people were found to have masked hypertension and 22.8 per cent had white coat hypertension.
“What also surprised us was that in India, unlike other countries, people have higher blood pressure in the evening than in the morning. We don’t understand why,” said Dr Upendra Kaul, the principal investigator of the study.
The study showed Rajasthan had the highest rate of white coat hypertension diagnoses at 42.5 per cent, while Bihar had the highest masked hypertension rate at 25.2 per cent.
“In the public health system, we usually test thrice for blood pressure before starting hypertension treatment. So overdosing patients who are not hypertensive does not happen,” said Dr Nikhil Patil, the in-charge of non-communicable diseases in the Directorate of Health Services.
Local health workers, however, claim that conducting three tests is time-consuming and multiple tests are only done for those who show high BP in their first test.
The Maharashtra government’s data shows 1.4 crore people have been screened since 2018, of which 2.53 lakh were diagnosed with hypertension.
Dr Yogesh Kalkonde from NGO Search, who treats hypertension in Gadchiroli, said there was a need to focus on the high drop-out rates from treatment and the need for increased coverage.
“Countries like Argentina distributed home-based BP machines for trial. In Western countries, wearable devices to measure BP are picking up. But in India, these trends are yet to set in,” he said.
Doctors said while home-based devices provide correct diagnoses, they need to be calibrated every six months for accuracy. In Gadchiroli, for instance, Kalkonde is using a simple measure to avoid white coat hypertension. He makes his nurse take the BP reading. “A patient gets high BP by just seeing a doctor. They feel more relaxed with a nurse,” he said.
Several pharmaceutical companies are also investing in ambulatory blood pressure monitoring devices to measure BP regularly over 24 hours for an accurate reading.