Background/Aims:
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 (BP) telemonitoring and pharmacist management intervention, with significant reductions in BP favoring the intervention arm over 18 months. This analysis examined the durability of the intervention effect on BP through 54 months of follow-up and compared BP measurements performed in the research clinic and in routine clinical care.
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. BP was measured as the mean of 3 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 systolic and diastolic BP (SBP and DBP).
Results:
Research clinic BP measurements were obtained from 326 (72%) study patients at the 54 month follow-up visit. Routine clinical care BP measurements were obtained from 444 (99%) of study patients from 7025 visits during the follow-up period. For TI patients, based on research clinic measurements baseline SBP was 148.2 mm Hg and 54 month follow-up was 131.2 mm Hg (-17.0 mm Hg, p<.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<.001). The differential reduction by study arm in SBP from baseline to 54 months was -1.0 mm Hg (95% 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<.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<.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). SBP and DBP results from routine clinical measurements closely approximated the pattern of results from research clinic measurements.
Conclusion:
Significant BP reductions in the TI arm relative to UC were no longer seen at 54 month follow-up. To maintain intervention benefits over a longer period of time additional intervention is needed.
HYPERDIRE, HYPERgeometric functions DIfferential REduction: MATHEMATICA-based packages for differential reduction of generalized hypergeometric functions