מדידת לחץ דם מעל שרוול דק? מדוייק או שגוי

26.04.26

נבדק ע״י חברנו פרופ׳ הלפרן פיני

OpenEvidence 26/4/2026

I am a physician. I keep being asked whether measuring oscillometric blood pressure while the cuff is placed on a shirt sleeve is accurate. Is there actual information regarding this topic?

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Yes, there is a meaningful body of evidence on this topic. Measuring oscillometric blood pressure over a thin sleeve (such as a short-sleeve shirt) does not appear to significantly affect accuracy, with most studies and a meta-analysis showing no clinically meaningful difference compared to bare-arm measurements. However, guidelines still formally recommend bare-arm measurement.

What the evidence shows:

A systematic review and meta-analysis of 13 studies found that measuring BP over a thin sleeve produced a nonsignificant SBP overestimation of only 0.59 mmHg (95% CI −0.11 to +1.30; P = 0.10). Even over a thicker sleeve, the overestimation was only 1.10 mmHg (95% CI −0.21 to +2.40; P = 0.10) — still not statistically significant. Notably, measuring below a rolled-up sleeve showed a larger (though still nonsignificant) overestimation of 2.76 mmHg, leading the authors to conclude that measuring over a thin sleeve "should be preferred to rolling it up".[1]

A study of 300 participants using an oscillometric device specifically found no significant differences in SBP or DBP across four conditions — bare arm, single-layer cotton shirt (~1 mm), two-layer cotton + sweater (~3 mm), and cotton + thick cardigan (~4 mm) — with mean differences all within 1.0 mmHg and excellent correlation (r > 0.95).[2]

The JACC Scientific Expert Panel on BP assessment also categorized "cuff placed over clothing" as having "not significant effects" on both SBP and DBP in its comprehensive table of sources of measurement inaccuracy.[3]

Counterpoint: One study in elderly patients (mean age 74.6 years) using a cardigan sleeve did find statistically significant BP overestimation (~4/5 mmHg) over the sleeve compared to bare arm.[4] Another study of 100 hypertensive patients found that while the mean group-level difference was not significant, the median absolute individual-level difference was 7–8 mmHg systolic, suggesting unpredictable directional effects in individual patients.[5]

What guidelines say:

Despite the largely reassuring evidence, the American Heart Association scientific statement on BP measurement still recommends placing the cuff on a "bare upper arm", and the JACC expert panel lists "remove clothing covering the location of cuff placement" as a key step.[6][3] This reflects a conservative approach to standardization rather than strong evidence of harm from thin sleeves.

Practical takeaway: For routine clinical screening with an oscillometric device, measuring over a thin single-layer sleeve (like a standard short-sleeve shirt fabric) is unlikely to introduce clinically meaningful error. Other common sources of inaccuracy — such as improper arm position, unsupported back, talking during measurement, or incorrect cuff size — have far greater impact on BP readings.[3][7] If a choice must be made between rolling up a tight sleeve (which can create a tourniquet effect) and measuring over a thin sleeve, measuring over the sleeve is preferable.[1]

Would you like to explore which other common sources of BP measurement error (such as arm position or cuff sizing) have the largest quantitative impact on readings?

References