Optimal schedule for home blood pressure measurement based on prognostic data: the Finn-Home Study

Abstract

Current guidelines based on cross-sectional statistical parameters derived from reference populations make equivocal recommendations for the optimal schedule of home blood pressure (BP) measurement. The objective of this study was to determine a schedule for home BP measurements in relation to their predictive value for total cardiovascular risk. Home BP was measured twice every morning and evening for 1 week in an unselected nationwide population of 2081 subjects aged 45 to 74 years. The prognostic significance of BP for fatal and nonfatal cardiovascular events was examined using adjusted Cox proportional hazards regression models. A total of 162 cardiovascular events were recorded during a 6.8-year follow-up. The predictive value of home BP increased progressively with the number of measurements, showing the highest predictive value with the average of all measurements (systolic/diastolic hazard ratio per 1-mm Hg increase in BP: 1.021/1.034; systolic/ diastolic 95% CI: 1.012 to 1.030/1.018 to 1.049). However, most of this increase was achieved during the first 3 days of measurement (hazard ratio: 1.017/1.028; 95% CI: 1.009 to 1.026/1.013 to 1.045), and only minimal increase occurred after day 6. No additional benefit was achieved by discarding the values obtained during the first day of measurement. Morning and evening BPs were equally predictive of future cardiovascular events. Novel prognostic data from this study show that measurement of home BP twice in the morning and evening, preferably for a period of 7 days, or for at least 3 days, provides a thorough image of a patient's BP level. This information should be used to prepare a unified international guideline for home BP measurement.