Australia’s first population-based study using ambulatory blood pressure monitoring has uncovered widespread underdiagnosis of hypertension, prompting a call for a new Medicare item for 24-hour monitoring.

Researchers from the Baker Heart and Diabetes Institute in Melbourne analysed 24-hour ambulatory blood pressure among 508 adults (mean age 59), a subcohort enrolled in the third Australian Diabetes, Obesity and Lifestyle Study (AusDiab3).

Comparing ambulatory blood pressure with office measurement, they estimated that 43% of participants were hypertensive yet only a quarter were taking blood-pressure-lowering medication.

The study found masked hypertension (where high blood pressure is not picked up in the clinic) among one in five participants, although there were “surprisingly” low levels of white-coat hypertension at 3%.