Accuracy of cuff blood pressure and systolic blood pressure amplification

Figures

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  Fig. 1. Bland-Altman plots of differences between cuff SBP (top) and cuff SBP corrected with SBP amplification (bottom) and invasive brachial SBP. Dashed lines represent the lines of best fit. Solid lines are mean difference ± 2 SDs. Bland-Altman plots show wide scatter and evidence of systematic bias for greater underestimation of invasive brachial SBP with increasing level of BP, but the slope of this association was significantly attenuated when cuff SBP was corrected by adding individual corresponding SBP amplification (r = −0.27 vs. r = −0.09, z = 5.25, p < 0.0001). There was a significant improvement in the mean difference between standard cuff and corrected cuff SBP from invasive brachial SBP (−7.6 ± 11.9 mmHg vs. −0.30 ± 11.4 mmHg, p < 0.001)

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  Fig. 2. Bar plots (mean, SE) cuff minus invasive brachial systolic blood pressure (SBP, top), diastolic (DBP, middle) and pulse pressure (PP, bottom) by invasive SBP amplification quintiles. There was a stepwise increase in mean differences between cuff and invasive brachial SBP, PP for each of elevated invasive SBP quintile (ptrend < 0.001) whilst there was a slight decrease for DBP (p = 0.04)