Attended vs. unattended blood pressure - learnings beyond SPRINT.

Blood pressure (BP) has been measured as office BP, usually taken after 5 minutes of quiet rest, in all clinical outcome trials in hypertension until recently, when the Systolic Blood Pressure Intervention Trial (SPRINT) was carried out. In the publication of the main SPRINT results it was not evident how BP had been measured (1). Following some literature search (2) it became visible that BP in SPRINT was taken as unattended automated office blood pressure (unattendedAOBP). The more than 100 sites participating in the SPRINT Study in the U.S.A. used the Omron 907 automated device. Personal were additionally trained to use the full capacity of this device by leaving the room prior to the 5 minutes period of rest followed by the preset unattended automated measurements at 5, 6 and 7 minutes. This is properly described in later publications including the article reporting the subgroup data in the elderly participants (3). However, a post hoc investigation in response to the debate suggested that not all investigators had followed the protocol and left the room prior to BP measurement (3). Alternatively, some of the SPRINT investigators years later may in fact not remember how their personal had performed the BP measurement.