1. Screening for hypertension using office-based blood pressure measurement (OBPM) resulted in major accuracy limitations, including misdiagnosis when compared with the current reference standard of ambulatory blood pressure measurement (ABPM).
2. Although hypertension screening is standard practice due to robust evidence linking asymptomatic treatment to improved cardiovascular disease (CVD) outcomes, further research is needed to determine optimal screening strategies and confirmatory algorithms for clinical practice.
Evidence Rating Level: 1 (Excellent)
Study Rundown: Hypertension is highly prevalent and one of the most important risk factors for cardiovascular disease (CVD). Prevention and early intervention including both pharmacologic and lifestyle modifications have been shown to improve CVD outcomes. Thus, accurate and effective measurement and monitoring of blood pressure remains extremely important in clinical practice. While office-based screening for hypertension in adults has been the standard of care for decades, blood pressure measurement (OBPM) may misclassify individuals due to large fluctuations in measurements and limited point-of-care accuracy (white coat or masked hypertension). Furthermore, the current gold standard for hypertension screening using ambulatory blood pressure measurement (ABPM) has been associated with tolerability concerns including temporary sleep disturbance, arm discomfort, and bruising. This systematic review sought to update evidence on the benefits and harms of screening and confirmatory blood pressure measurements in adults, in order to inform the US Preventive Services Task Force. The main outcomes of the selected studies included mortality, CVD events, quality of life, sensitivity, specificity, positive and negative predictive values, and harms of screening. In total, 52 studies (N = 215,534) were selected and used to address four key areas – 1) association of hypertension screening with improved health outcomes, 2) accuracy of OBPM as a single-encounter screening tool compared to ABPM, 3) accuracy of confirmatory blood pressure measurement in adults who initially screen positive compared to ABPM, and 4) harms of screening for hypertension in adults. The review demonstrated that screening using OBPM had major accuracy limitations including large measurement fluctuations and misdiagnosis when compared to the reference standard of ABPM. However, direct harms caused by blood pressure measurement were minimal. Due to the limited accuracy of OBPM and poor tolerability and practicality of ABPM in certain individuals, further research is required to determine optimal screening and confirmation for hypertension in the clinical setting. A limitation of this review was that it excluded accuracy studies in which 20% or more of participants were treated to approximate screening populations. The accuracy of blood pressure measurements may be influenced by blood pressure variability, and variability may be reduced by hypertension medications. Therefore, these pooled accuracy estimates may not be applicable to treated populations.
Relevant Reading: Comparing automated office blood pressure readings with other methods of blood pressure measurement for identifying patients with possible hypertension: a systematic review and meta-analysis
In-Depth [systematic review and meta-analysis]: This systematic review and updated evidence report for the US Preventive Services Task Force included 52 studies from MEDLINE, PubMed, Cochrane Collaboration Central Registry of Controlled Trials, and CINAHL surveyed through March 2021. The study used randomized clinical trials (RCTs) and nonrandomized controlled intervention studies to determine effectiveness of screening; accuracy studies for screening and confirmatory measurements; RCTs, nonrandomized controlled intervention studies, and observational studies for harms of screening and confirmation. A total of 215,534 participants were identified in the 52 selected studies. There were no population-based trials comparing hypertension screening with no screening due to feasibility and ethical concerns. One community-based cluster RCT (n = 140,642) of a multicomponent CVD health promotion trial reported fewer annual CVD-related hospital admissions in the intervention group compared with the control group, but no difference in all-cause mortality (difference, 3.02 per 1000 people; rate ratio, 0.91 [95%CI, 0.86-0.97]). Meta-analysis of 15 studies (n = 11,309) using initial OBPM screening showed a pooled sensitivity of 0.54 (95%CI, 0.37-0.70) and specificity of 0.90 (95%CI, 0.84-0.95), with considerable clinical and statistical heterogeneity. Furthermore, 18 studies (n = 57,128) of various confirmatory blood pressure measurement modalities were heterogeneous. Meta-analysis of 8 office-based compared to 4 home-based confirmation studies (n = 53,183 vs 1,001) showed a pooled sensitivity of 0.80 (95%CI, 0.68-0.88) and 0.84 (95%CI, 0.76-0.90) respectively, and specificity of 0.55 (95%CI, 0.42-0.66) and 0.60 (95%CI, 0.48-0.71) respectively. Lastly, 13 studies (n = 5,150) suggested that screening was associated with no decrease in quality of life or psychological distress. However, ABPM was associated with minor adverse events including temporary sleep disturbance, arm discomfort, and bruising.
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