Unattended versus attended automated office blood pressure: Systematic review and meta-analysis of studies using the same methodology for both methods

There is increasing interest in unattended automated office blood pressure (OBP) measurement, which gives lower blood pressure values than the conventional auscultatory OBP. Whether unattended automated OBP differs from standardized attended automated OBP performed using the same device and measurement protocol remains uncertain. A systematic review and meta-analysis of studies (aggregate data) comparing unattended vs attended automated OBP using the same device and measurement protocol (conditions, number of measurements, visits) was performed. Ten eligible studies (n = 1004, weighted age 60.8 ± 4.2 [SD] years, 55% males) were analyzed. Unattended OBP (pooled systolic/diastolic 133.9 [95% CI: 129.7, 138]/80.6 [95% CI: 77, 84.2] mm Hg) did not differ from attended OBP (135.3 [95% CI: 130.9, 139.6]/81 [95% CI: 77.6, 84.3] mm Hg); pooled systolic OBP difference -1.3, 95% CI: -4.3, 1.7 mm Hg and diastolic -0.4, 95% CI: -1.2, 0.3 mm Hg. Nine of ten studies achieved high quality score and no publication bias was identified. Meta-regression analysis did not reveal any effect of age, gender, or attended systolic OBP on the unattended-attended systolic OBP difference (P = NS for all). However, there was a trend toward higher attended than unattended OBP at higher OBP levels. These data suggest that, when the same device and measurement protocol are used, attended automated OBP provides similar blood pressure values as unattended automated OBP. Although unattended automated OBP is theoretically advantageous as it ensures that standardized conditions and measurement protocol are used, attended automated OBP, if carefully performed, appears to be a reasonable and practical alternative.