Planned sample size and analysis Our sample size is based on equivalence of BpTRU measurement done in non private office areas as compared to measurement done in private office areas, using the results of our pilot study. We consider differences of less than 5 mm Hg in systolic blood pressure to be clinically equivalent. In order to demonstrate equivalence for our primary outcome, and accounting for clustering effect in primary care offices, using a power of 80% and a two sided alpha level of 0.05 to conclude equivalency for a difference of 5 mm Hg or less, we will need to recruit 350 patients. Our planned recruitment is therefore fifty patients per office and seven office locations. 175 patients (25 per office location) will be randomly allocated to BpTRU measurement in a private exam room first and 175 will be allocated to an open area first.