title: Agreement between different frequencies of measurements in ambulatory blood pressure monitoring.
abstract: The purpose of this study was to determine the degree of agreement among different frequencies of blood pressure measurements (FoM) in 24-hour ambulatory blood pressure monitoring (ABPM) in their ability to obtain useful clinical information. ABPM records were obtained with a Del Mar IV Avionics device from 49 hospitalised preeclamptic women with a FoM of 7 per hour (high-FoM). With these records, we simulated two sets of data as if measurements had been recorded at a rate of 1 measurement per hour (low-FoM) and of 2 per hour (medium-FoM). Diastolic blood pressure > 89 mmHg defined hypertension and > 109 mmHg, severe hypertension The median and 25th and 75th centiles for the differences in hypertensive rate detected (expressed as percentage points) between lowFoM vs. high-FoM was 0.00 (- 3.4-3.00) and between medium-FoM vs. high-FoM,- 1.04 (- 3.7-1.5). The agreement in the detection of severely affected patients was 85% (CI 95%: 74-96) between low-FoM and high-FoM and 87% (CI 95%: 77-98), between medium-FoM and high-FoM. Average blood pressure was similar in the three FoMs studied at day-time and night-time. We did not find any strong argument to perform ABPM at a high-FoM. Lower FoM are more comfortable for the patient and could reduce equipment deterioration, while providing equivalent information to that supplied by high-FoM.
authors.affiliation: Department of Obstetrics and Gynaecology, Juan A. Fernández Hospital, University of Buenos Aires, Argentina.
authors.forename: R L
authors.initials: RL
authors.lastname: Lede
authors.forename: L S
authors.initials: LS
authors.lastname: Voto
authors.forename: J
authors.initials: J
authors.lastname: Orti
authors.forename: M
authors.initials: M
authors.lastname: Margulies