Powers, Benjamin JOlsen, Maren KSmith, Valerie AWoolson, Robert FBosworth, Hayden BOddone, Eugene Z2024-02-012024-02-012011-060003-48191539-3704https://hdl.handle.net/10161/30096<h4>Background</h4>The optimal setting and number of blood pressure (BP) measurements that should be used for clinical decision making and quality reporting are uncertain.<h4>Objective</h4>To compare strategies for home or clinic BP measurement and their effect on classifying patients as having BP that was in or out of control.<h4>Design</h4>Secondary analysis of a randomized, controlled trial of strategies to improve hypertension management. (ClinicalTrials.gov registration number: NCT00237692)<h4>Setting</h4>Primary care clinics affiliated with the Durham Veterans Affairs Medical Center.<h4>Patients</h4>444 veterans with hypertension followed for 18 months.<h4>Measurements</h4>Blood pressure was measured repeatedly by using 3 methods: standardized research BP measurements at 6-month intervals; clinic BP measurements obtained during outpatient visits; and home BP measurements using a monitor that transmitted measurements electronically.<h4>Results</h4>Patients provided 111,181 systolic BP (SBP) measurements (3218 research, 7121 clinic, and 100,842 home measurements) over 18 months. Systolic BP control rates at baseline (mean SBP<140 mm Hg for clinic or research measurement; <135 mm Hg for home measurement) varied substantially, with 28% classified as in control by clinic measurement, 47% by home measurement, and 68% by research measurement. Short-term variability was large and similar across all 3 methods of measurement, with a mean within-patient coefficient of variation of 10% (range, 1% to 24%). Patients could not be classified as having BP that was in or out of control with 80% certainty on the basis of a single clinic SBP measurement from 120 mm Hg to 157 mm Hg. The effect of within-patient variability could be greatly reduced by averaging several measurements, with most benefit accrued at 5 to 6 measurements.<h4>Limitation</h4>The sample was mostly men with a long-standing history of hypertension and was selected on the basis of previous poor BP control.<h4>Conclusion</h4>Physicians who want to have 80% or more certainty that they are correctly classifying patients' BP control should use the average of several measurements. Hypertension quality metrics based on a single clinic measurement potentially misclassify a large proportion of patients.<h4>Primary funding source</h4>U.S. Department of Veterans Affairs Health Services Research and Development Service.HumansHypertensionBlood Pressure DeterminationBlood Pressure Monitoring, AmbulatoryProbabilityFollow-Up StudiesBlood PressureAgedMiddle AgedQuality Assurance, Health CareFemaleMaleJournal article