Ps-c08-3: too-large and too-small cuff sizes results results in substantial blood pressure measurement error: results from the cuff(sz) randomized trial

Objective: Proper cuff-size based on measured mid-arm circumference is recommended for accurate blood pressure (BP) determination. The impact of mis-cuffing (using a too-small or too-large cuff) on BP when using an automated BP device has not been rigorously tested. We aimed to determine the effects of mis-cuffing on automated BP. Design and Methods: We conducted a randomized cross-over trial of 195 community-dwelling adults [mean age 54 yrs, 34% male (n = 67), 68% Black (n = 132)]. Participants had 3 sets of triplicate BP measurements (WelchAllyn ProB 2000) using an appropriately sized cuff and two additional cuff sizes (too-small and/or too-large), in random order. Results: 31% (n = 60) of the study participants had systolic BP (SBP) > = 130 mmHg, and 36% (n = 71) had a body mass index > = 30 kg/m2. As shown in the Figure, among persons in whom a small adult cuff was appropriately sized, too-large cuffs resulted in significantly lower SBP readings [regular adult cuff: -3.6 (-1.7 to -5.6) and large adult cuff: -7.5 (-5.5 to -9.6)]. In contrast, among persons in whom an extra-large adult cuff was appropriately sized, too-small cuffs resulted in significantly higher SBP readings [large adult cuff: + 9.6 (+7.3 to + 11.9) and regular adult cuff: + 19.5 (+16.1 to + 22.9)]. Similar effects were seen for mis-cuffing when an appropriate cuff was either a regular adult cuff or large adult cuff. We also observed similar patterns for diastolic BP. Conclusions: Appropriate cuff selection is essential for accurate BP measurement. Choosing a too-large or too-small cuff can result in clinically meaningful errors in BP reading which could lead to under- or over-treatment of hypertension.