The Dübendorf Study: a population-based investigation on normal values of blood pressure self-measurement

There is evidence that self-measurement of BP increases precision, reproducibility and prognostic value of BP measurement. However, generally accepted normal values for BP values obtained by self-measurement are still missing. The present study was undertaken to investigate differences between office and self-measured blood pressure; 503 randomly selected inhabitants (265 men and 238 women, age 20-90 years, mean age 46.5 +/- 12.9 years) of the small town of Dübendorf in Switzerland were studied. The subjects were not preselected according their BP levels, only patients taking antihypertensive drugs were excluded. Self-measurement was performed at home by the subjects during 14 days in the morning between 6 and 8 am and in the evening between 6 and 8 pm (mean of 26.7 measurements). Office BP was taken before and after the two week period. Mean office BP (130.0 +/- 16.5/82.1 +/- 11.1 mmHg) was significantly (P < 0.01) higher than mean self-measured BP (123.1 +/- 14.6/77.6 +/- 10.7 mmHg). There was no significant difference between first and second office BP measurement. Morning self-measured BP was lower than evening pressure (delta 4.0/1.4 mmHg, both P < 0.01) and the mean was taken for comparison with office BP.(ABSTRACT TRUNCATED AT 250 WORDS)