The reliability of blood pressure (BP) monitors is a prerequisite for the accurate evaluation of hypertension. Validation protocols have been developed to evaluate the accuracy of BP monitors, and the European Society of Hypertension International Protocol (ESH-IP) is the most widely used worldwide. A review of published validation studies using the revised ESH-IP 2010 (ESH-IP2) was performed, to identify possible violations, divergences and adaptations.Design and method:
Published validation studies that used the ESH-IP2 from its publication (2010) until the end of 2015 were identified. All aspects of the protocol procedure were scrutinized using a standard checklist.Results:
147 validation studies were identified: 92 (63%) used the ESH-IP, 22 (15%) the British Hypertension Society Protocol, 26 (18%) the US AAMI and/or ISO protocol, and 18 (12%) did not follow an established protocol (some studies used two protocols). Of the 92 ESH-IP studies 54 (59%) used the ESH-IP2. The number of ESH-IP2 studies published per year were 7/3/9/16/19 for years 2011/12/13/14/15 respectively. 52 studies reported a ‘pass’ result (96.3%). 93% of the studies tested oscillometric devices, 78% upper-arm devices, 20% clinic, 6% ambulatory and 89% home monitors (some for more than one function). Four studies (7%) included special populations (children, renal disease patients, intensive care unit patients). The ESH-IP2 was adapted for specific device type or population in 5 studies. Protocol violations were identified in 17 studies (some two or more violations), involving sample size, recruitment criteria, simultaneous measurements, or combined use of ESH-IP1 and ESH-IP2 criteria. Most frequent violations were diastolic BP distribution range (19% of studies), BP recruitment range (15%), participants’ age (6%). One study with ESH-IP2 criteria indicating ‘fail’ concluded ‘pass’. Detailed information on cuffs use, and on recruitment and distribution BP ranges was omitted in 29 studies (54%).Conclusions:
Five years after its publication, the revised ESH-IP2 remains the preferred protocol for device validation. Protocol violations occur in one third of the studies, suggesting that a more strict standardization of the validation procedure and reporting is necessary. The peer review process of scientific journals often misses important deficiencies of validation studies.