After intervention , the latest mean systolic blood pressure was 131.7 ( SD , 16.8 ) mm Hg in the control trial arm and 131.4 ( 16.7 ) mm Hg in the intervention trial arm , and adjusted mean difference was -0.56 mm Hg ( 95 % confidence interval , -1.38 to 0.26 ; P = 0.183 ) .