Long-Term Outcomes of a Cluster-Randomized Trial Testing the Effects of Blood Pressure Telemonitoring and Pharmacist Management
Background: Hypertension is a common condition and leading cause of cardiovascular disease. We previously reported results of a cluster-randomized trial evaluating a home blood pressure telemonitoring and pharmacist management intervention, with significant reductions in systolic blood pressure (SBP) favoring the intervention arm found over 6, 12 and 18 months and in diastolic blood pressure (DBP) found over 6 and 12 months. This analysis examined the durability of the intervention effect on blood pressure through 54 months of follow-up.
Methods: The Hyperlink trial randomized 16 primary care clinics having 450 study-enrolled patients with uncontrolled hypertension to either telemonitoring intervention (TI) or usual care (UC) study arms. Blood pressure was measured as the mean of three measurements obtained at each research clinic visit. General linear mixed models utilizing a direct likelihood-based ignorable approach for missing data were used to examine change from baseline to 54 months in SBP and DBP.
Results: Blood pressure measurements were obtained from 164 (74%) in UC and 162 (71%) of TI patients at the 54-month follow-up visit. For TI patients, baseline SBP was 148.2 mm Hg and 54-month follow-up was 131.2 mm Hg (-17.0 mm Hg, P < 0.001). For UC patients, baseline SBP was 147.7 mm Hg and 54-month follow-up was 131.7 mm Hg (-16.0 mm Hg, P < 0.001). The differential reduction by study arm in SBP from baseline to 54 months was -1.0 (95% confidence interval [CI]: -5.4 to 3.4, P = 0.63). For TI patients, baseline DBP was 84.4 mm Hg and 54-month follow-up was 77.8 (-6.6 mm Hg, P < 0.001). For UC patients, baseline DBP was 85.1 mm Hg and 54-month follow-up was 79.1 mm Hg (-6.0 mm Hg, P < 0.001). The differential reduction by study arm in DBP from baseline to 54 months was -0.6 mm Hg (95% CI: -3.5 to 2.4, P = 0.67).
Conclusion: Significant blood pressure reductions in the TI arm relative to UC were no longer seen at 54-month follow-up. More work is needed to ascertain the optimal duration and reinforcement that could be used to maintain intervention benefits over a longer period of time.
Asche S, Bergdall A, Dehmer S, Green B, Sperl-Hillen J, O'Connor P, Nyboer R, Pawloski PA, Maciosek M, Trower N, Margolis K. Long-term outcomes of a cluster-randomized trial testing the effects of blood pressure telemonitoring and pharmacist management. J Patient Cent Res Rev. 2017;4:166.