How in-office and ambulatory BP monitoring compare: A systematic review and meta-analysis.

Purpose: We performed a literature review and meta-analysis to ascertain the validity of office blood pressure (BP) measurement in a primary care setting, using ambulatory blood pressure measurement (ABPM) as a benchmark in the monitoring of hypertensive patients receiving treatment. Methods: We conducted a literature search for studies published up to December 2013 that included hypertensive patients receiving treatment in a primary care setting. We compared the mean office BP with readings obtained by ABPM. We summarized the diagnostic accuracy of office BP with respect to ABPM in terms of sensitivity, specificity, and positive and negative likelihood ratios (LR), with a 95% confidence interval (CI). Results: Only 12 studies met the inclusion criteria and contained data to calculate the differences between the means of office and ambulatory BP measurements. Five were suitable for calculating sensitivity, specificity, and likelihood ratios, and 4 contained sufficient extractable data for meta-analysis. Compared with ABPM (thresholds of 140/90 mm Hg for office BP; 130/80 mmHg for ABPM) in diagnosing uncontrolled BP, office BP measurement had a sensitivity of 81.9% (95% CI, 74.8%-87%) and specificity of 41.1% (95% CI, 35.1%-48.4%). Positive LR was 1.35 (95% CI, 1.32-1.38), and the negative LR was 0.44 (95% CI, 0.37-0.53). Conclusion: Likelihood ratios show that isolated BP measurement in the office does not confirm or rule out the presence of poor BP control. Likelihood of underestimating or overestimating BP control is high when relying on in-office BP measurement alone.

Validity of clinic blood pressure compared to ambulatory monitoring in hypertensive patients in a primary care setting.

AIMS: To determine the validity of the blood pressure (BP) measurement in a primary care setting in comparison with the measurement obtained from 24-h ambulatory blood pressure monitoring (ABPM). METHODS: Patients with hypertension (n = 137) were studied in primary care. Immediately after a nurse took two measurements of each patient's BP, the ABPM device was attached. Agreement was determined using the Bland-Altman method and the Kappa index. The sensitivity, specificity, predictive values and likelihood ratios were calculated for the manual BP measurement in comparison with ABPM for the purpose of diagnosing uncontrolled BP. RESULTS: The BP values from ABPM were lower than those obtained in the examination room. The difference between the clinic measurement and the ABPM was 18.07 ± 14.6 mmHg (systolic blood pressure, SBP) and 6.3 ± 9.2 mmHg (diastolic blood pressure, DBP). The agreement between the clinic measurement and 24h-ABPM for the purpose of classifying control or uncontrolled BP was 64.2% (Kappa = 0.311). In the case of ABPM, the sensitivity of the measurement in the examination room for diagnosing uncontrolled BP was 80.36%, specificity was 53.09%, positive predictive value 54.22% and negative predictive value 70.63%. CONCLUSIONS: Clinic measurements do not have sufficient sensitivity/specificity to be recommended as a single method of BP control in primary care.