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Evidence Summary

Blood Pressure in Adults (Hypertension): Screening

October 15, 2007

Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.

Evidence for the Reaffirmation of the U.S. Preventive Services Task Force Recommendation on Screening for High Blood Pressure

Tracy Wolff, MD, MPHa, and Therese Miller, DrPH.a

Address correspondence to: Drs. Wolff and Miller, U.S. Preventive Services Task Force Program, Agency for Healthcare Research and Quality, 540 Gaither Road, Rockville, MD 20850.

This article was first published in the Annals of Internal Medicine. Select for copyright and source information.

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Background: High blood pressure is common, and screening is a well-established evidence-based standard of current medical practice.

Purpose: To perform a literature search for new, substantial evidence on screening for high blood pressure that would inform the reaffirmation of the U.S. Preventive Services Task Force recommendation on screening for high blood pressure.

Data Sources: The PubMed® and Cochrane databases were searched. The searches were limited to English-language articles on studies of adult humans (age >18 years) that were published between 1 October 2001 and 31 March 2006 in core clinical journals.

Study Selection: For the literature on benefits, meta-analyses; systematic reviews; and randomized, controlled trials were included. For harms, meta-analyses; systematic reviews; randomized, controlled trials; cohort studies; case-control studies; and case series of large, multisite databases were included. Two reviewers independently reviewed titles, abstracts, and full articles for inclusion.

Data Extraction: No new evidence was found on benefits or harms of screening. Two reviewers extracted data from studies on the harms of early treatment, including adverse effects of drug therapy and adverse quality-of-life outcomes.

Data Synthesis: No new evidence was found for the benefits of screening for high blood pressure. New evidence on the harms of treatment of early hypertension shows that pharmacologic therapy is associated with common side effects; serious adverse events are uncommon.

Limitations: The nonsystematic search may have missed some smaller studies on the benefits and harms of screening and treatment for high blood pressure.

Conclusion: No new evidence was found on the benefits of screening. Pharmacotherapy for early hypertension is associated with common side effects.

 
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Hypertension is usually defined in adults as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher.1 Data from NHANES III (Third National Health and Nutrition Examination Survey) suggest that an estimated 43 million U.S. adults older than 25 years have hypertension and that hypertension is more common in African American and elderly persons than in other groups. In the United States, hypertension is responsible for 35% of myocardial infarctions and strokes, 49% of episodes of heart failure, and 24% of premature deaths. Additional complications of hypertension include end-stage renal disease, retinopathy, and aortic aneurysm.2-4

In 2006, the U.S. Preventive Services Task Force (USPSTF) decided to reexamine the evidence in order to reaffirm its 2003 recommendation on screening for high blood pressure (or hypertension). The Task Force issues a reaffirmation update for a topic that the USPSTF decides to keep current because the topic is one of its priorities, is within its scope, and is a topic for which there is a compelling reason to make a recommendation. Topics in this category are well-established evidence-based standards of current medical practice. The USPSTF decided to perform a reaffirmation update because the evidence base on hypertension is strong and only large, high-quality studies would overturn such a recommendation. Such recommendations would previously have been an A or D recommendation. Therefore, we performed a literature search for new, substantial evidence that would be sufficient to change the 2003 recommendation.

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The USPSTF developed 2 key questions to be addressed: 1) What are the benefits of screening for high blood pressure in adults? 2) What are the harms of screening and/or early treatment of high blood pressure? To determine whether the benefits of screening for hypertension continue to outweigh the harms, the USPSTF included new information on the adverse effects of drug therapy for "early hypertension" as part of the question on harms.

Data Sources and Searches

We performed nonsystematic literature searches of PubMed® and the Cochrane Library. We used the following search terms: hypertension, mass screening, adverse effects, and false positive results. We limited the searches to English-language studies of adult humans (age >18 years) that were published in core clinical journals between 1 October 2001 and 31 March 2006. "Core clinical journals" are a subset of 120 English-language journals defined by the National Library of Medicine; it was previously known as the Abridged Index Medicus. We also checked reference lists of systematic reviews and other studies for possibly relevant studies.

Study Selection

We included studies on benefits and harms of screening and treatment of "early hypertension." We understood "early hypertension" to be blood pressure elevation that screening could reasonably identify. We defined "early hypertension" as prehypertension (systolic blood pressure of 120 to 139 mm Hg or diastolic blood pressure of 80 to 89 mm Hg), hypertension detected through screening, or untreated or newly diagnosed mild to moderate hypertension (systolic blood pressure of 140 to 180 mm Hg or diastolic blood pressure of 90 to 110 mm Hg, when information was not given about how hypertension was detected). We excluded studies in very high-risk or special populations, including patients with preexisting cardiovascular disease.

We included studies of nonpregnant adults older than 18 years. We included studies from the United States and from countries with patient populations that are generalizable to the United States. For the literature on benefits, we included meta-analyses; systematic reviews; and randomized, controlled trials. For harms, we included meta-analyses; systematic reviews; randomized, controlled trials; cohorts; case- control studies; and case series of large, multisite databases. We excluded editorials, case reports, nonsystematic reviews, and guideline reports.

Data Extraction

No studies were included for data abstraction on the benefits or harms of screening. For harms of early treatment, 2 reviewers abstracted information on sample size, entry criteria, demographic characteristics, comorbid conditions, study design, treatment group allocation, reports of adverse effects of drug therapy, and quality-of-life outcomes.

Data Synthesis and Analysis

Data from the included studies were synthesized qualitatively in tabular and narrative formats.

Role of the Funding Source

The work of the USPSTF is supported by the Agency for Healthcare Research and Quality. No separate funding was used specifically for this study.

 
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The search returned 378 potentially relevant titles, which we entered into a reference database. A total of 341 studies were excluded after title review, 19 studies were excluded after abstract review, and 13 were excluded after full article review. We excluded 253 studies that were not on hypertension, 62 that included a high-risk population, 31 that did not meet study design criteria, 12 that were not from a U.S. population, 8 that were not done in adults, and 7 that had no relevant outcomes.

No new studies on the benefits or harms of screening for high blood pressure met our inclusion criteria. Five studies evaluated the harms of early treatment of hypertension and met our inclusion criteria (Table); these are discussed below.

Three studies presented data on adverse effects related to antihypertensive drugs. These studies compared outcomes from treatment of one type of drug versus another type of drug or placebo. In general, they were multicenter studies in the United States, Canada, and United Kingdom; included a predominantly white, male patient sample; and excluded persons with multiple comorbid conditions or manifest cardiovascular disease. In addition, 2 studies examined the effects of antihypertensive medications on quality of life. In these 2 studies, participants with untreated hypertension were randomly allocated to different treatment regimens (the second study also included a placebo group) and followed for effects on quality of life: sexual dysfunction in one study, and "symptom distress" in the other study. The study on sexual dysfunction included men 40 to 49 years of age, and the study on symptom distress included men and women 50 years of age or older.

In 1 study that gathered data on adverse effects, White and colleagues studied the effect of bedtime dosing on early-morning blood pressure in 261 persons who were randomly allocated to 10 weeks of extended-release diltiazem or ramipril.5 Adverse effects were reported in 50% of the diltiazem group and 40% of the ramipril group. Serious adverse effects were uncommon, and 2 of the 3 reported events were probably not related to the drug: 1 event occurred during placebo run-in, and 1 was associated with infection. The most common reasons for withdrawal from the study were lower-extremity edema associated with diltiazem (3%) and cough associated with ramipril (2%). Headache was commonly reported in both groups. The main finding of the study was that diltiazem at bedtime reduced early-morning blood pressure to a greater extent than ramipril.

Julius and colleagues compared candesartan with placebo in participants with systolic blood pressure of 130 to 139 mm Hg and diastolic blood pressure of 89 mm Hg or less.6 Serious adverse effects were uncommon, occurring in 3.5% of candesartan recipients and 5.9% of placebo recipients. However, other, less serious adverse effects were very common, occurring in approximately 89% of participants in both the candesartan and placebo groups. Commonly reported adverse effects in the candesartan group were headache (22%), upper respiratory infection (14%), nasopharyngitis (10%), and dizziness (10%).

A third study evaluated the effectiveness in reducing clinic-measured and ambulatory blood pressure of 4 antihypertensive agents (doxazosin, amlodipine, enalapril, and bendrofluazide) in 204 persons with diastolic blood pressure of 95 to 110 mm Hg.7 The authors reported that clinic-measured and ambulatory blood pressure decreased in all groups, with no significant differences among them; the authors did not report data that allowed us to determine the statistical significance of this comparison. Adverse effects were very common and did not statistically significantly differ among treatment groups (overall rate, 74% [range among groups, 68% to 81%]). Serious adverse effects were uncommon (overall rate, 11% [range, 6% to 14%]), and the rate of withdrawals due to adverse events was 11%. The most commonly reported adverse effect was headache (overall rate, 20% [range, 16% to 25%]).

In 1 study with quality-of-life outcomes, Fogari and colleagues followed 160 married men 40 to 49 years of age with newly diagnosed hypertension (diastolic blood pressure of 95 to 110 mm Hg) who had never been treated for hypertension and had no symptoms of sexual dysfunction.8 One hundred twenty men were randomly assigned to receive an angiotensin II receptor antagonist (valsartan) or a beta-blocker (carvedilol) for 16 weeks, and, after a placebo washout period, were crossed over to the alternative regimen for another 16 weeks; 40 men were randomly assigned to receive placebo. Results indicated that carvedilol caused a decline in sexual function (the rate of sexual intercourse decreased by 50%, and 13.5% of patients experienced sexual dysfunction). Valsartan produced a temporary and non-statistically significant decline in sexual function, and function improved with ongoing treatment: By 16 weeks, the rate of sexual intercourse had increased by 19%. The 2 drugs did not differ in control of blood pressure.

The other study with quality-of-life outcomes evaluated symptom distress associated with a calcium-channel blocker (amlodipine) and an aldosterone receptor antagonist (eplerenone).9 A total of 269 men and women 50 years of age or older with untreated seated systolic blood pressure of 140 to 190 mm Hg were randomly assigned to receive 1 of the study drugs after a placebo run-in period. On average, participants were approximately 68 years of age, and 89% were white. Participants were followed for 24 weeks; quality-of-life measures were collected at randomization, 14 weeks, and 24 weeks. At 24 weeks, the groups did not statistically significantly differ in blood pressure control or scores on the Short Form-36 Health Survey. However, there was a statistically significant difference among treatment groups on a summary measure of symptom distress in favor of eplerenone (P = 0.03). The amlodipine group experienced symptoms commonly associated with the drug, including ankle swelling, headache, facial flushing, and constipation. Twenty-five percent of amlodipine recipients and 5% of eplerenone recipients experienced edema. Other adverse events were hyperkalemia in 2 eplerenone recipients and 1 amlodipine recipient, and hypokalemia in 2 amlodipine recipients. Erectile dysfunction was reported by 2 of 61 eplerenone recipients and no amlodipine recipients.

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In summary, there is no new evidence on the benefits of screening for high blood pressure. New evidence on the harms of treatment of early hypertension shows that pharmacologic therapy is associated with common side effects; serious adverse events are uncommon.

 
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Author Affiliation

a Drs. Wolff and Miller: U.S. Preventive Services Task Force Program, Agency for Healthcare Research and Quality.

Disclaimer

The authors of this article are responsible for its contents, including any clinical or treatment recommendations. No statement in this article should be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.

Copyright and Source Information

This document is in the public domain within the United States.

Requests for linking or to incorporate content in electronic resources should be sent via the USPSTF contact form.

Reprints are available from the USPSTF Web site (www.uspreventiveservicestaskforce.org).

Source: U.S. Preventive Services Task Force. Evidence for the reaffirmation of the U.S. Preventive Services Task Force recommendation on screening for high blood pressure. Ann Intern Med 2007:147(11):787-91

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Author, Year (Reference) Study Objective Sample Characteristics Inclusion Criteria Design Study Groups
Fogari, et al., 20018 To evaluate the effects of valsartan and carvedilol on sexual function in men n=160
Age: 40-49 y
All married
Newly diagnosed hypertension

Men never treated for hypertension

DBP ≥95 but <110 mm Hg

No sexual dysfunction
RCT 120 patients received carvedilol or valsartan for 16 wk, followed by 4 wk of placebo; they then "crossed over" to alternative regimen for another 16 wk.

40 patients received only placebo
Hollenberg, et al., 20039 To evaluate symptom distress associated with eplerenone compared with amlodipine n=269
Mean age:
67 y, eplerenone group;
69 y, amlodipine group
White: 89%
Age >50 y

Men and women

Untreated SBP 140-190 mm Hg
Randomized trial 134 patients received eplerenone

135 patients received amlodipine

Patients were followed for 24 wk; QOL measures at 14 and 24 wk were SF-36 Health Survey (8 aspects of health-related QOLb), Symptom Distress Index (73 items), and Cantril's Ladder (0-10 ladder grade of QOL)
White, et al., 20045 To determine whether extended-release diltiazem at bedtime is superior to ramipril at bedtime for control of early-morning BP n=261
Mean age: 54 y
Men: 61%
White: 93%
DBP 90-110 mm Hg during run-in placebo period

Patients with history of CAD, stroke, CHF, secondary hypertension, cardiac conduction abnormalities, poorly controlled DM, malabsorption, or CRF were excluded
Multicenter randomized trial in the United States and Canada Extended-release diltiazem, 240, 360, or 540 mg at bedtime

Ramipril, 5, 10, or 20 mg at bedtime

2-wk prestudy washout of hypertension medications, 3- to 4-wk placebo run-in, then 10 wk of treatment
Julius, et al., 20066 To examine whether treatment of prehypertension with candesartan prevents or postpones stage 1 hypertension n=809
Mean age: 48 y
Men: 59%-60%
White: 80%-84%
Mean BMI: 30 kg/m2
Age 30-65 y

Not receiving treatment for hypertension

Average BP: SBP, 130-139 mm
Hg; DBP <89 mm Hg
Multicenter double-blind RCT in the United States Placebo for 4 y

Candesartan, 16 mg, for 2 y, then placebo for 2 y

3-wk run-in period

If hypertension developed, patients were given metoprolol or hydrochlorothiazide
Ebbs, 20017 To determine whether ambulatory BP monitoring can assess the effectiveness of selected antihypertensives in maintaining 24-hour BP control n=204
Mean age: 54-58 y
Men: 43%-48%
White: 99%

Mean BP:
SBP, 152-161 mm Hg;
DBP, 97-100 mm Hg
DBP 95-110 mm Hg

Patients with treatment for hypertension, symptomatic CVD, end-organ damage, secondary or malignant hypertension, intolerance of study medications, hypercholesterolemia, type 1 DM, renal impairment, or pregnancy were excluded
Multicenter randomized trial in the United Kingdom 1) Doxazosin, 1, 2, or 4 mg
2) Amlodipine, 5 or 10 mg
3) Enalapril, 5, 10, or 20 mg
4) Bendrofluazide, 2.5 or 5 mg

8-wk placebo run-in period

Treatment for up to 14 wk and titrated to achieve BP control and then treatment for another 8 wk

 

Author, Year (Reference) Comparison of Groups and Withdrawals Main Results Adverse Events Summary
Fogari, et al., 20018 6 patients were lost to follow-up: 2 had hypotension, and 4 in placebo group had hypertension ≥110 mm Hg Mean number of intercourse episodes:
At 4 wk: reduced by 43% with carvedilol and by 20% with valsartan (P < 0.05)
At 16 wk: reduced by 50% with carvedilol but increased by 19% with valsartan
Erectile dysfunction:
15 patients (13.5%) receiving carvedilol
1 patient receiving valsartan and 1 receiving placebo (P < 0.001)
Carvedilol produced a decline in sexual function (decreased frequency of sexual activity and increased number of patients who had sexual dysfunction).

Valsartan produced a temporary, nonsignificant decline in sexual function and improved function with ongoing treatment.

The drugs did not differ in terms of BP control.
Hollenberg, et al., 20039 Groups did not differ in age, sex, ethnicity, employment, initial QOL, or baseline BP

Dropout rates did not differ by group but were higher for amlodipine (30 patients [25%]) than eplerenone (19 patients [16%])
Average decrease in Symptom Distress Index score with amlodipine and increase in score for eplerenone (P = 0.03); 36 of 73 symptoms favored eplerenone, and 1 favored amlodipine

No significant differences in SF-36 Health Survey results

Amlodipine was significantly associated with ankle swelling, headache, facial flushing, constipation, and pronounced heartbeat

Both drugs decreased SBP; amlodipine significantly decreased DBP
No eplerenone side effects related to an action on steroid receptors

No cases of gynecomastia, tender breasts, or menstrual irregularities

Edema: 25% with amlodipine vs. 5% with eplerenone
Amlodipine was associated with annoying but not life-threatening side effects.
White, et al., 20045 90% of diltiazem recipients and 92% of ramipril recipients completed the study

AEs were the most common reason for dropping out
Diltiazem reduced early morning BP to a greater extent than ramipril (-18/-15 mm Hg vs. -13/-8 mm Hg; P < 0.001) ≥1 AE occurred in 50% of diltiazem recipients and 40% of ramipril recipients

No deaths

Withdrawals:
3 patients with serious AE: 1 during placebo run-in, 1 in diltiazem group (facial/peripheral edema), 1 in ramipril group (severe UTI)
Most common reason for withdrawal: leg edema with diltiazem (3%), cough with ramipril (2%)

Other AEs:
Ramipril:
cough (8%)
headache (12%)
lower-extremity edema (2%)
Diltiazem:
cough (0.8%)
headache (5%)
lower-extremity edema (13%)
AEs were very common (40%-50% of patients) with both drugs.

Serious AEs were uncommon (2%-3%), and 2 of the 3 reported were probably not related to the drug.
Julius, et al., 20066 - Candesartan significantly decreased risk for hypertension at the end of 4 y (relative risk, 0.84) Serious AEs: 3.5% of candesartan recipients, 5.9% of placebo recipients

Other AEs: 89% of candesartan recipients, 88.5% of placebo recipients

AEs with higher rate with candesartan vs. placebo:
Headache: 21.5%
URI: 14.4%
Nasopharyngitis: 10%
Dizziness: 10%
Fatigue: 8.1%
Pain in extremity: 7.6%
Insomnia: 5.6%
Anxiety: 5.6%
Hypotension: 1%
Syncope: 0.5%
AEs were very common (about 89% of participants).

Serious AEs were uncommon (3.5% of candesartan recipients).
Ebbs, 20017 - 24-h ambulatory SBP and DBP decreased in all groups; no significant differences among groups 74% of participants reported an AE

Withdrawals: 11% overall owing to an AE

Most common AE: headache (20%)
AEs were very common (74%); the most common AE was headache.

Serious AEs were uncommon (11%).

a. AE = adverse effect; BMI = body mass index; BP = blood pressure; CAD = coronary artery disease; CHF = congestive heart failure; CRF = chronic renal failure; CVD = cardiovascular disease; DBP = diastolic blood pressure; DM = diabetes mellitus; QOL = quality of life; RCT = randomized, controlled trial; SBP = systolic blood pressure; SF-36 = Short Form-36; URI = upper respiratory tract infection; UTI = urinary tract infection.
b. The 8 aspects of health-related QOL are physical function, role—physical, bodily pain, general health, vitality, social functioning, role—emotion, and mental health.

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