This allowed the introduction of the so called wide-range cuff for devices designed for self-BP measurement at home, which appeared on the market over a decade ago [3]. Despite being provided with cuffs of standard size, these cuffs proved to be accurate over a broad range of upper-arm circumferences, usually from 22 to 42 cm. In one study, a cuff with a 14.5 × 32 cm bladder could provide accurate oscillometric BP measurements even in individuals with arm circumferences up to 52 cm [4]. The use of these cuffs can avoid the problem of miscuffing in obese individuals and eliminate the need to supply several different cuffs for home BP measurement. However, a recent review of published validation studies indicates deficiencies in the assessment of the accuracy of wide range cuffs [5]. One main concern with the use of these cuffs is that, in past validation studies, the full range of arm circumferences was evaluated only in a few studies, with the upper and lower extremes of the range being ignored. Indeed, there was some evidence that using wide-range cuffs and bladders could lead to misdiagnosis of hypertension [6]. This limitation has been overcome with the introduction of the ISO protocol in 2018, which included arm size distribution among the criteria for subject recruitment [1].
The above considerations stress the importance of appropriate cuff size selection for accurate BP measurement. To this purpose, device sellers must encourage users to purchase properly sized cuffs according to current recommendations. However, whether the cuffs provided by manufacturers are consistent with recommended sizes is unclear. This issue was addressed by Trivedi and Coll in the present study aimed to assess cuff size needs of Australian users according to mid-arm circumferences [7]. The authors made a cross-sectional analysis of arm size among Australian adults to assess the appropriateness of cuff sizes of common in-clinic and home BP monitors. Based on typical in-clinic cuff sizes, most Australians would require a medium (51.7%) or large (44.5%) cuff. Mid-arm circumference was categorized by cuff sizes available with the top ten most commonly used home devices in Australia: standard (22-32 cm) or wide-range (22-42 cm) cuffs. For home devices, which are usually supplied with a single cuff size, the standard 22-32 cm cuff would not fit 48.3% (10.3 million) adults, and the wide-range 22-42 cm cuff would not fit 3.8% (701,995) adults. Quite understandably, these proportions were much greater for people with obesity, being 92.3% for standard cuff and 11.9% for wide-range cuff. Inconsistencies between cuffs currently marketed by manufacturers and recommendations of regulatory bodies or scientific societies are common to other countries. According to a recent report by Shahi and Coll, 20 (47.6%) out of the 42 validated BP monitors in U.S.A. offered multiple cuff sizes and 32 devices offered a broad-range cuff [8]. However, only 5 devices offered an extra-large cuff. Over half of devices offered only a broad range size that may not be appropriate for smaller arms and may not cover larger arms. In addition, cuff sizes did not align size ranges recommended by the American Heart Association. Another problem is that different manufacturers have varying ranging for cuff sizes and use different terminologies to refer to similar sizes, which can create confusion among users. Discrepancies in terminologies make it difficult for health care providers to advice patients about purchasing the appropriate cuff. Manufacturers and sellers should provide cuffs designed for a specific range of arm circumferences rather than use the size terminology (such as standard, large, etc.). The above studies provide evidence supporting the use of individualized BP cuff sizes clearing up the misconception that the selection of appropriately sized cuffs should be dichotomized to standard size and large size arms.