Assessment of ambulatory blood pressure recorders: accuracy and clinical performance

There are now more than ten different manufacturers of non-invasive, portable blood pressure monitors in North America, Europe, and Japan. These ambulatory blood pressure recorders measure blood pressure by either auscultatory or oscillometric methodology. Technologic advances in the recorders have resulted in reduction in monitor size, reduction in or absence of motor noise during cuff inflation, ability to program the recorder without an external computer system, and enhanced precision. Recently, there has been concern that more structured validation protocols have not been implemented prior to the widespread marking of ambulatory blood pressure recorders. There is a need for proper assessment of recorders prior to use in clinical research or practice. Data on several existing recorders suggest that while most are reasonably accurate during resting measurements, many lose this accuracy during motion, and clinical performance may vary among the monitors. Validation studies of ambulatory recorders should include comparison with mercury column and intra-arterial determinations, resting and motion measurements, and assessment of clinical performance in hypertensive patients.