Figueiredo Daniela, Azevedo Ana, Pereira Marta, de Barros Henrique
Department of Hygiene and Epidemiology, University of Porto Medical School, Porto, Portugal.
Rev Port Cardiol. 2009 Jul-Aug;28(7-8):775-83.
A diagnosis of hypertension should be based on multiple blood pressure (BP) measurements, taken on at least two separate occasions. We aimed to assess the impact of considering different criteria for a definition of hypertension, based on number of visits for blood pressure measurement, on estimates of hypertension prevalence, awareness, treatment and control, and on its association with two variables definitely related to hypertension: body mass index and left ventricular hypertrophy.
We used data from a cross-sectional study of 739 participants, aged > or = 45 years, randomly selected from a non-institutionalized Portuguese population, from January 2001 to December 2003. Main outcome measures were prevalence of hypertension (systolic BP > or = 140 mmHg and/or diastolic BP > or = 90 mmHg or current antihypertensive drug therapy) based on BP measurements on one visit, on BP measurements on a second visit or on fulfilling the same criteria on the two different visits.
Estimated hypertension prevalence was 63.4% (95% CI: 59.8-66.9) using BP measurements from the first visit (HTN1) and 60.2% (95% CI: 56.6-63.8) using BP measurements from the second visit (HTN2). If both visits are used as criteria the estimated hypertension prevalence (HTN(Final)) was 56.3% (95% CI: 52.7-60.0), p (McNemar test) < 0.001, between HTN1 and HTN(Final) and between HTN2 and HTN(Final). Awareness, treatment and control changed from 60.2% to 64.4%, 53.1% to 59.8% and 24.9% to 22.0%, respectively, when using information from the first or both visits. All three different estimates of hypertension prevalence have a similar strong and independent association with body mass index (OR = 2.71 for body mass index > or = 30 with HTN(Final)) and with left ventricular hypertrophy (OR = 3.21 for HTN(Final) with left ventricular hypertrophy).
In many individuals labeled as hypertensive on a single evaluation, hypertension was not confirmed on reassessment, leading to a significant overestimation of 12.6% of the true prevalence. For this reason BP should be measured on at least two office visits both for clinical purposes and in epidemiological studies. On the other hand, this did not reflect on the association between hypertension and body mass index or left ventricular hypertrophy, suggesting that unconfirmed cases do not necessarily imply misclassification.
高血压的诊断应基于多次血压测量，且至少在两个不同场合进行测量。我们旨在评估基于血压测量就诊次数来考虑高血压定义的不同标准，对高血压患病率、知晓率、治疗率和控制率估计值的影响，以及其与两个明确与高血压相关的变量：体重指数和左心室肥厚之间的关联。
我们使用了2001年1月至2003年12月从葡萄牙非机构化人群中随机选取的739名年龄≥45岁参与者的横断面研究数据。主要结局指标为基于一次就诊时的血压测量、第二次就诊时的血压测量或两次不同就诊时均符合相同标准的高血压患病率（收缩压≥140 mmHg和/或舒张压≥90 mmHg或当前正在接受降压药物治疗）。
使用首次就诊时的血压测量值（HTN1）估计的高血压患病率为63.4%（95%可信区间：59.8 - 66.9），使用第二次就诊时的血压测量值（HTN2）估计的患病率为60.2%（95%可信区间：56.6 - 63.8）。如果将两次就诊结果均作为标准，估计的高血压患病率（HTN（最终））为56.3%（95%可信区间：52.7 - 60.0），HTN1与HTN（最终）之间以及HTN2与HTN（最终）之间的p值（McNemar检验）<0.001。当使用首次就诊或两次就诊的信息时，知晓率、治疗率和控制率分别从60.2%变为64.4%、53.1%变为59.8%以及24.9%变为22.0%。所有三种不同的高血压患病率估计值与体重指数（对于HTN（最终），体重指数≥30时的比值比 = 2.71）和左心室肥厚（对于HTN（最终），有左心室肥厚时的比值比 = 3.21）均有相似的强且独立的关联。
在许多单次评估被标记为高血压的个体中，再次评估时高血压未得到确认，导致对真实患病率高估了12.6%。因此，出于临床目的和流行病学研究，血压应至少在两次门诊就诊时进行测量。另一方面，这并未影响高血压与体重指数或左心室肥厚之间的关联，表明未得到确认的病例不一定意味着分类错误。
