Objective: To evaluate the reproducibility of blood pressure measured at home (HBP) in comparison with ambulatory (ABP) and clinic blood pressure (CBP) in children and adolescents.
Participants and methods: Individuals aged 8-17 years who had been referred for elevated CBP were included. CBP was measured at two visits, HBP on 5 days and ABP for 24 h. A second session including all the above measurements was performed after 8 weeks. The reproducibility of CBP (second visit of each session), HBP (average of days 2-5 of each session) and ABP (average 24-h, awake and asleep) was quantified using test-retest correlations coefficients (r) and the standard deviation of differences (SDD) between repeated measurements.
Results: Sixteen individuals were included [mean age 13.3+/-2.9 (SD)] years, range 8-17, nine boys]. According to Task Force CBP criteria, eight were classified as hypertensives, three as high normal and five as normotensives. The reproducibility of HBP (systolic/diastolic r, 0.74/0.82, SDD 7.0/4.3) was superior to that of CBP (r, 0.63/0.80, SDD 10.4/6.3). However, ABP appeared to provide the most reproducible values (r, 0.87/0.84, SDD 5.5/4.3 for 24-h ABP; r, 0.85/0.76, SDD 5.9/5.0 for awake; r, 0.76/0.79, SDD 7.0/5.0 for asleep ABP). Aspects of the diurnal ABP variation were poorly reproducible (r, 0.62/0.14, SDD 6.8/5.5 for awake-asleep ABP difference; r, 0.55/0.26, SDD 0.07/0.11 for awake : asleep ratio).
Conclusion: These data suggest that in children and adolescents home blood pressure measurements are more reproducible than clinic measurements. However, 24-h ambulatory monitoring appears to provide the most reproducible blood pressure values.