Evidence Table 2

Quality assessments of randomized controlled trials of beta blockers for hypertension

Author
Year
Country
Randomization describedAllocation concealedGroups similar at baselineSimilarity to target populationNumber recruitedExclusion criteria for recruitmentEligibility criteria specifiedOutcome assessors blindedCare provider blindedPatient unaware of treatmentIntention-to-treat (ITT) analysisMaintenance of comparable groupsReporting of attrition, crossovers, adherence, and contaminationLoss to follow-up: differential/highScoreFundingControl group standard of careLength of follow-up
Head-to-head controlled trials
Walle
1994
NRNRUnclearMean age=58 years
43.3% male
Race NR
60Cardiiovascular diseases, such as angina pectoris, secondary hypertension, grade II or III AV block, heart failure, or a history of myocardial infarction (within 12 months); cerebrovascular ischemia: asthma/chronic bronchitis; insulin-dependent diabetes; and malignancy or chronic disease requiring treatmentYesYesYesYesNo
13 (21.7%) excluded due to protocol violations
UnclearYes
No
No
No
No
No
FairNRYes6 weeks
Sundar
1991
NRNRn/a-crossoverMean age=NR
100% male
100% Indian
NRPatients with accociated conditions like moderate to severtr congestive infarction within 6 months, accelerated hypertension and those with severe gastrointestinal, renal or hepatie dysfunction were excludedYesYesYesYesUnclearUnclearYes
No
No
No
Unclear
Unclear
PoorNRYes4 weeks
Steiner
1990
NRNRNRBaseline characteristics
NR
489 screened, 360 eligiblePatients could not have major concomitant medical or mental problems or significant changes in living conditions (e.g., recent death of spouse), or require concomitant therapy that could confound the study resultsYesYesYesYesNo; 16 (4.4%) were excluded due to protocol violationsUnclearYes
No
No
No
NRFairICI Pharmaceuticals GroupYes4 weeks
Dahlof
1988
NRNRn/a-crossoverMean age=54.466.2% male
Race NR
NR1. The patient had not followed the instructions to fill in and return the questionnaire on 3 occasions during the run-in period
2. The diastolic blood pressure <90mmHg or >105mmHg
3. Previous treatment with metoprolol or atenolol
4. AV-block 2 or 3
5. Non-compensated congestive heart failure
6. Insulin-treated diabetes
7. Bradycardia (heart rate <50 beats/min)
8. Bronchial asthma
9. Any serious concomitant illness or drug abuse which can interfere with the treatment
10. Unwillingness to participate in the study
YesYesYesYesNo; excluded 3 patients (3.9%) due to AE's (1 patient in each group) and noncompliance (group NR)n/a - crossoverYes
No
No
No
No
No
FairNRYes6 weeks
Blumenthal
1988
NRNRNRMean age=42.5 years
100% male
84.6% white
62% antihypertensive treatment naïve
26NRYesYesYesYesUnclearNRNo
No
No
No
NR
NR
PoorJohn D. and Catherine T. MacArthur Foundation, National Institutes of Health greants HL30675, HS31514, and AG04238, and a grant (RO7233) from the US Public Health ServicesYes2 weeks
Buhler
1986
NRNRn/a - crossoverMean age=53.3 years
76.1% male
Race NR
138Patients were on other antihypertensive drugs, had contraindications for beta-blocker therapy, severe disease, or who were known for their poor compliance. Patients with impaired renal function, i.e., serum creatinine>150 umol/l, were also excluded.YesYesYesYesNo
30 (22.4%) were excluded due to BP limits or nondrug related problems
Yes
N=104
Mean age=53.3
82.7% male
No
No
FairNRYes8 weeks
Placebo-controlled trials
Oberman 1990
Wassertheil-Smoller 1991
Wassertheil-Smoller 1992
United States

Trial of Antihypertensive
Interventions and Management (TAIM)
NRNRNRMean age=49
56% male
878 randomized
697 analyzed
History of myocardial infarction, stroke, or asthma, or a serum creatinine level of 177 mmol/d or greater, insulin-dependent diabetes, allergy to thiazides or beta-blockers, pregnancy, or likelihood of difficulty in complying with the interventionsYesNRYesYesNoNRAttrition: 181(20.6%); compliance(% of patients taking > 80% of the pills): 92%; others NRNoneFairICI Pharmaceuticals; A.H Robins; National Heart, Lung and Blood InstituteYes6 months
Perez-Stable 2000Adequate: computer- generated list of random numbersNRNo; statistically significant differences between the two groups on two tests of cognitive functionFair
Mean age=45.5; 66.5%
male
312Concomitant use of insulin, bronchodilators, antidepressants or antihypertensive medications within 1 month of screening; coronary artery disease, vascular heart disease, renal insufficiency, cerebrovascular disease, and secondary causes of hypertensionYesNRYesYesNoNR45% attrition; others NRNRFairPublic Health Services GrantsYes12 months
Anonymous 1977
Greenberg 1984
Anonymous 1985
Miall 1987
Anonymous 1988a
Anonymous 1988b
Anonymous 1992
Lever 1993

Medical Research Council (MRC)

UK
NRNRYesMean age 52
52.1% male
515,000 screened
46,350 eligible
17,354 enrolled
Secondary hypertension; already on antihypertensive treatment; cardiac failure; MI or stroke within previous 3 months, angina; intermittent claudication; diabetes; gout; asthma; other serious disease; pregnancyYesYes; assessed by an arbitrator ignorant of the treatment regimenYesYesYesNRAttrition due to primary and adverse events reported; others NRNRFairDuncan, Flockhart and Co Ltd; Imperial Chemical Industries Ltd; CIBA
Laboratories; Merck Sharp and Dohme Ltd
Yes5 years
Head-to-head trials
Brixius
2007
computer generated adequateNRYesmean age: group A 48.4; group B 47.2
Male: 100%
Ethnicity: NR
Yes
Screened: 50
Enrolled: 48
YesYesNR (stated double-blind, no details given)NR (stated double-blind, no details given)NR (stated double-blind, no details given)YesYesNo
No
Yes
No
NRfairNRyes28 weeks
Yilmaz
2008
Turkey
NRNo
Open-label
NR, only analyzed subjects’ characteristics reportedBaseline characteristics for patients who completed the study only.
Mean age: 40.7
Male: 51%
Unknown
Screened: 56
Enrolled: 46
YesYesNoNoNoNo, 3 patients were excluded from analysisYesYes
No
Yes
No
NoFairUlagay-Menarini Group, Istanbul, Turkey
Menarini International, Florence Italy
Yes6 weeks

From: Evidence Tables

Cover of Drug Class Review: Beta Adrenergic Blockers
Drug Class Review: Beta Adrenergic Blockers: Final Report Update 4 [Internet].
Helfand M, Peterson K, Christensen V, et al.
Portland (OR): Oregon Health & Science University; 2009 Jul.
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