Reporting of consistency of blood pressure control in randomized controlled trials of antihypertensive drugs: a systematic review of 1372 trial reports.
ABSTRACT Hypertension is a powerful treatable risk factor for stroke. Reports of randomized controlled trials (RCTs) of antihypertensive drugs rightly concentrate on clinical outcomes, but control of blood pressure (BP) during follow-up is also important, particularly given that inconsistent control is associated with a high risk of stroke and that antihypertensive drug classes differ in this regard.
We performed a systematic review of reporting of BP control in RCTs of antihypertensive drugs. We searched bibliographic databases (1950-2009) for systematic reviews of RCTs of BP-lowering and identified the main report of all trials.
We identified 94 larger trials (>100 participants/arm, >1-year follow-up) and 1278 smaller/shorter trials. Ninety-one (96.8%) larger trials reported some data on mean BP during follow-up, but none reported effects on the consistency of control of BP over time. Although 81 (86.2%) larger trials reported group distribution of BP at baseline (usually SD), only 22 (23.4%) reported such data at any follow-up visit. Eleven (11.7%) larger trials reported group distribution of the change in BP from baseline to follow-up, but 61 (64.9%) reported no data at all on group distribution of BP at follow-up. Thirty-nine (41.5%) trials reported the proportion of patients reaching some BP target during follow-up, but no trial reported data on the consistency of control to target within individuals over time. Similar proportions were observed in the 1278 smaller/short trials.
Reporting of BP control is limited in RCTs of BP-lowering drugs. We suggest reporting guidelines.
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ABSTRACT: Uncontrolled blood pressure (BP) increases cardiovascular risk, independent of type of treatment. In this posthoc International Verapamil SR-Trandolapril Study analysis, we determined whether adverse outcomes are related to consistency of BP control, defined as the proportion of visits in which BP was in control. A total of 22 576 patients with hypertension and coronary artery disease were divided into 4 groups according to the proportion of visits in which BP was in control (<140/90 mm Hg): <25%, 25% to <50%, 50% to <75%, and >or=75%. Risk of primary outcome (first occurrence of death, nonfatal myocardial infarction, or nonfatal stroke), myocardial infarction, and stroke decreased progressively from the group with <25% to the group with >or=75% of visits with BP control. Adjusted risks of primary outcome (heart rate: 0.60; 95% CI: 0.53 to 0.67), myocardial infarction (heart rate: 0.58; 95% CI: 0.48 to 0.70), and stroke (heart rate: 0.50; 95% CI: 0.37 to 0.67) were less in the group with >or=75% of visits with BP control compared with the group with <25% of visits with BP control. Baseline BP was not predictive of outcomes. Proportion of visits with BP control was associated with mean follow-up systolic BP (r(2)=0.64), both being independently related to primary outcome. As proportion of visits with BP control increases, there is an associated steep reduction in cardiovascular risk, independent of baseline characteristics and mean on-treatment BP. Consistency of BP control during treatment provides additional information on the protective effect of antihypertensive treatment. Physicians need to be concerned at each visit if BP is not controlled.Hypertension 08/2007; 50(2):299-305. · 6.87 Impact Factor
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ABSTRACT: To determine the value of monitoring blood pressure by quantifying the probability that observed changes in blood pressure reflect true changes. Analysis of blood pressure measurements of patients in the perindopril protection against recurrent stroke study (PROGRESS). Randomised placebo controlled trial carried out in 172 centres in Asia, Australasia, and Europe. 1709 patients with history of stroke or transient ischaemic attack randomised to fixed doses of perindopril and indapamide. Measurements Mean of two blood pressure measurements in patients receiving treatment recorded to the nearest 2 mm Hg with a standard mercury sphygmomanometer at baseline and then at three months, six months, nine months, and 15 months and then every six months to 33 months. There was no change in the mean blood pressure of the cohort during the 33 month follow-up. Six months after blood pressure was stabilised on treatment, if systolic blood pressure was measured as having increased by >10 mm Hg, six of those measurements would be false positives for every true increase of >or=10 mm Hg. The corresponding value for an increase of 20 mm Hg was over 200. Values for 5 mm Hg and 10 mm Hg increases in diastolic blood pressure were 3.5 and 39, respectively. The likelihood that observed increases in blood pressure reflected true increases rose with the time between measurements such that the ratio of true positives to false positives reached parity at 21 months. Usual clinical approaches to the monitoring of patients taking drugs to lower blood pressure have a low probability of yielding reliable information about true changes in blood pressure. Evidence based guidelines for monitoring treatment response are urgently required to guide clinical practice. Trial registration Australia and New Zealand Clinical Trial Registry.BMJ (Clinical research ed.). 01/2009; 338:b1492.
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ABSTRACT: Systematic reviews and meta-analyses are essential to summarise evidence relating to efficacy and safety of healthcare interventions accurately and reliably. The clarity and transparency of these reports, however, are not optimal. Poor reporting of systematic reviews diminishes their value to clinicians, policy makers, and other users. Since the development of the QUOROM (quality of reporting of meta-analysis) statement-a reporting guideline published in 1999-there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realising these issues, an international group that included experienced authors and methodologists developed PRISMA (preferred reporting items for systematic reviews and meta-analyses) as an evolution of the original QUOROM guideline for systematic reviews and meta-analyses of evaluations of health care interventions. The PRISMA statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review. In this explanation and elaboration document, we explain the meaning and rationale for each checklist item. For each item, we include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature. The PRISMA statement, this document, and the associated website (www.prisma-statement.org/) should be helpful resources to improve reporting of systematic reviews and meta-analyses.BMJ (Clinical research ed.). 02/2009; 339:b2700.