FOR HOW MANY DAYS SHOULD BLOOD-PRESSURE BE MEASURED AT HOME IN OLDER PATIENTS BEFORE STEADY LEVELS ARE OBTAINED

This study investigated the period of time that blood pressure (DR) sh ould be measured at home in older patients in order to obtain steady B P values. Thirty-six men and 38 women (greater than or equal to 60 yea rs) were recruited at one family practice. At one office visit the fam ily physician measured supine, sitting and standing BPs three times co nsecutively in each position. During 10 consecutive days, BP was measu red at home five times daily. The supine and standing BPs were measure d once in the morning and in the evening and the sitting BP once at no on, These home BP values were averaged over the first day (1-day), ove r the first 3 days (3-day) and all 10 days (10-day) of measurements. I n both the supine (-5.1 mm Hg) and sitting (-3.8 mm Hg) positions the 10-day average systolic home BP was significantly lower than the corre sponding office BP. The opposite was observed for the 10-day average s tanding home BP values (+7.3/+3.4 mm Hg), Comparison of the 3-day and 10-day average home BP values showed only a significantly lower 10-day than 3-day systolic BP level in the supine position (-1.1 mm Hg, 95% Cl -1.9 to -0.2 mm Hg). Repeated measures ANOVA, showed a small but si gnificant decrease over time only for the supine systolic home BP (-0. 29 mm Hg per day, 95% Cl -0.49 to -0.08 mm Hg per day). We conclude th at in older subjects, 3 days of home measurements may suffice to obtai n steady values for the sitting and standing BPs, A longer interval mi ght be required for the supine BP.