Automated non-invasive blood pressure devices: are they suitable for use?

Abstract

Measurement of blood pressure by a trained observer using a mercury sphygmomanometer is accepted as the gold standard, but there has been an increase in the use of automated devices employing the oscillometric technique. Not all such devices have been clinically validated, and some do not carry an appropriate CE mark. This survey aimed to assess the state of the European Union market for automated non-invasive blood pressure devices in terms of information provided by companies relating to compliance, validation and intended use. A total of 116 companies were identified as being potentially active (i.e. manufacturer, supplier, agent or distributor). Of these, 110 that could be contacted were asked to provide details of their company and their non-invasive blood pressure products via a questionnaire. Eighty-six companies were found to be actively involved in the supply of 158 different models of automated non-invasive blood pressure device. These included 54 devices for use on the arm and 62 for use on the wrist (total 116 in our main categories), and 42 others (ambulatory monitors, patient monitors, defibrillators or finger devices). We received responses for 61% (71/116) of the main category arm and wrist devices and 80% (57/71) of these provided claims for CE marking. Of the CE marked devices for which we received a response, 41% (12/29) of arm devices and 39% (11/28) of wrist devices claimed some form of clinical validation, or evidence was found subsequent to the survey. Of these claims, 65% (15/23) related to an earlier, or similar, product and 48% (11/23) were based on published studies. Inconsistencies were found between claims for diagnostic suitability and claims for clinical validation. A majority of models available on the European Union market were not validated by clinical trial to one of the recognized protocols.