Component Description
This section provides data for three consecutive blood pressure (BP) and pulse measurements using an oscillometric device.
Eligible Sample
Participants aged 8 years and older were eligible. Participants with any of the following on both arms were excluded from the exam: rashes, gauze dressings, casts, edema, paralysis, tubes, open sores or wounds, withered arms, and A-V shunts. Also, women who have had an axillary nodal biopsy or resection, or a unilateral radical mastectomy, do not have their blood pressure measured in the affected arm.
Protocol and Procedure
All BP measurements are taken in the mobile examination center (MEC). Prior to obtaining BP measurements, upper arm circumference is measured, which is done to guide selection of cuff size.
After resting quietly in a seated position for 5 minutes, three consecutive BP measurements (systolic and diastolic) were taken 60 seconds apart using a digital upper-arm electronic blood pressure measurement device, Omron HEM–907XL. This device has been previously validated by both the Association for the Advancement of Medical Instrumentation (AAMI) and the International Protocol of the European Society of Hypertension for taking BP measurements in populations aged 13 years and older (White et. al., 2002; Ombani et. al., 2007; Ostchega et. al., 2010).
BP measurements were taken in the right arm unless specific conditions prohibited the use of the right arm, or if participants reported any reason that the BP measurements should not be taken in the right arm.
Details on the protocol for obtaining upper arm circumference and BP are described in the NHANES August 2021–August 2023 procedure manuals.
Quality Assurance & Quality Control
The BP examiners were certified for BP measurement through a training program and followed a strict standardized BP protocol. In addition, examiners were observed to assure that BP readings were obtained following the standardized protocol. Health technician performance was also monitored using data reviews.
Data Processing and Editing
The following are some specifications used in capturing the BP data:
- Systolic BP cannot be greater than 300 mmHg;
- Systolic blood pressure must be greater than diastolic BP;
- If there is no systolic BP, there can be no diastolic BP. However, there can be a systolic measurement without a diastolic measurement.
Analytic Notes
After the 2017-2018 survey cycle, NHANES stopped collection of auscultatory BP measurements using a mercury sphygmomanometer. During the 2017-2018 survey cycle, blood pressure was collected using both auscultatory (with a mercury sphygmomanometer) and oscillometric (with the Omron HEM–907XL) methods. Additional details and results from the study, comparing auscultatory and oscillometric BP measurements, are available in an NCHS Vital and Health Statistics Series 2 Report at NCHS website (Ostchega et. al., 2021).
Exam sample weights should be used for analyses. Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.