An extended validation of the ScottCare 320 ambulatory blood pressure monitor: Recommendations for clinical application

Objectives: The purpose of this study was to validate the ScottCare 320 ambulatory blood pressure monitor (ABPM) using both group-level and individual-level validation procedures. The group-level validation followed a modified protocol of the European Hypertension Society's validation protocol. The individual-level validation was conducted to ensure that the monitor is valid from both a research and clinical perspective. Methods: Participants (n=41) had three simultaneous blood pressure (BP) measurements taken by a trained listener using a mercury column sphygmomanometer and the ScottCare ABPM, which was used to validate the monitor at the group-level and the first half of the individual-level validation (i.e. the difference between the ABPM and auscultatory means for each participant <5 mmHg). The second half of the individual-level validation occurred by examining participants' responses on diary questionnaires taken immediately following the BP measurements (i.e. can extreme or deviant BP values be explained by situational factors). Results: At the group level, the ABPM passed the criteria laid out by the European Hypertension Society. At the individual level, the difference between the auscultatory and ABPM means was less than 5 mmHg for both systolic and diastolic BP for 36 participants on the initial attempt, and the remaining five on the second attempt. Furthermore, the deviant values were largely attributed to explainable causes, mainly movement. Conclusion: The ScottCare ABPM is a highly accurate monitor that can be considered valid at both the group and the individual level, and thus appropriate for both clinical and research use.