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Table 2 Data extraction of the meta-analysis

From: Effectiveness and safety of beta blockers in the management of hypertension in older adults: a systematic review to help reduce inappropriate prescribing

Khan et al. 2006. Re-examining the efficacy of β–blockers for the treatment of hypertension: a meta-analysis, CMAJ, 174(12): 1737-42 [33]
Country Canada
Funding Not stated
Setting Not stated
Objective To explore the efficacy (stroke, myocardial infarction and death) of beta blockers in different age groups
Inclusion and exclusion criteria
Population Hypertension, distinguish between “younger” patients <60 years (mean age ranged from 45.5 to 56.2 years, n=10 trials and n=50,612 patients) and “older” patients ≥60 years (60.4 to 76 years, n=11 trials and n=95,199 patients, 9 trials out of 11 with mean age ≥65 years).
Intervention Beta blocker as first-line therapy for hypertension in preventing major cardiovascular events
Control No treatment, placebo, diuretic, ACE inhibitor, calcium-channel blocker, angiotensin-receptor blocker
Outcomes Stroke, myocardial infarction, or death
Study designs Randomized controlled trials
Methods
Study design Systematic review including meta-analysis. Results of the individual studies are combined to produce an overall statistic.
Last date searched 18 January 2006
Data bases searched PubMed (1950-18.01.2006)
Other sources searched Hand search, reference lists of published hypertension meta-analysis (MEDLINE) and the Cochrane Library. Contacted Canadian hypertension experts.
Number of included studies 21 Randomized controlled trials
Number of included patients 145,811
Outcomes, results
Primary
Composite cardiovascular outcome of death, nonfatal myocardial infarction or nonfatal stroke Beta blockers reduced event rates compared with placebo (RR 0.86, 95% CI 0.74–0.99, based on 794 events in 19,414 patients), in trials enrolling younger patients, but benefits were not found in trials enrolling older patients (RR 0.89, 95% CI 0.75–1.05, based on 1115 events in 8,019 patients).
Among 30,412 patients younger than 60 years of age, there was no difference in event rates between those randomly assigned to beta blockers therapy compared with those receiving other antihypertensive agents (1515 events, RR 0.97, 95% CI 0.88–1.07). However, in the 79,775 patients 60 years of age or older, beta blockers were associated with a higher risk of events than other antihypertensive agents (7405 events, RR 1.06, 95% CI 1.01–1.10).
Secondary
Beta blocker compared to placebo “Younger population” < 60 years “Older population” ≥ 60 years
Death RR 0.94, 95% CI 0.79–1.10 RR 0.91, 95% CI 0.74–1.12
Nonfatal myocardial infarction RR 0.85, 95% CI 0.71–1.03 RR 0.98, 95% CI 0.83–1.16
Nonfatal stroke RR 0.84, 95% CI 0.65–1.10 RR 0.78, 95% CI 0.63–0.98
Heart failure RR 1.05, 95% CI 0.72–1.54 RR 0.54, 95% CI 0.37–0.81
Beta blocker compared to other antihypertensive agents “Younger population” < 60 years “Older population” ≥ 60 years
Death RR 0.97, 95% CI 0.83–1.14 RR 1.05, 95% CI 0.99–1.11
Nonfatal myocardial infarction RR 0.97, 95% CI 0.86–1.10 RR 1.06, 95% CI 0.94–1.20
Nonfatal stroke RR 0.99, 95% CI 0.67–1.44 RR 1.18, 95% CI 1.07–1.30
Heart failure RR 0.93, 95% CI 0.64–1.34 RR 0.98, 95% CI 0.87–1.11
Subgroup analysis, ≥60 years
Beta blocker compared to placebo or no treatment
(5 trials and n=8,019 patients, range mean age 65 to 75.7 years)
Composite cardiovascular outcome of death, nonfatal myocardial infarction or nonfatal stroke Beta-blockers´ benefits were not found in trials enrolling older patients
RR 0.89, 95% CI 0.75–1.05, based on 1,115 events in 8,019 patients.
Death RR 0.98, 95% CI 0.83–1.16
Nonfatal myocardial infarction RR 0.98, 95% CI 0.83–1.16
Nonfatal stroke RR 0.78, 95% CI 0.63–0.98
Heart failure RR 0.54, 95% CI 0.37–0.81
Beta blocker compared to other antihypertensive agents
(7 trials and n=87,180 patients, range mean age 60.4 to 76 years)
Composite cardiovascular outcome of death, nonfatal myocardial infarction or nonfatal stroke Beta blockers were associated with a higher risk of events than were other antihypertensive agents (7,405 events, RR 1.06, 95% CI 1.01–1.10).
Death RR 1.05, 95% CI 0.99–1.11
Nonfatal myocardial infarction RR 1.06, 95% CI 0.94–1.20
Nonfatal stroke RR 1.18, 95% CI 1.07–1.30
Heart failure RR 0.98, 95% CI 0.87–1.11
Conclusion
Beta blockers should not be considered first-line therapy for older hypertensive patients without another indication for these agents; however, in younger patients beta blockers are associated with a significant reduction in cardiovascular morbidity and mortality.
Quality appraisal
Quality criteria for systematic reviews and meta-analyses Author´s judgement Support for judgement
Precise and accurately defined research question (e.g. PICO) Yes Criteria for considering studies are explicitly explained in the paper. The PICOS scheme can be applied
Well-defined selection criteria Yes See above
Was an ‘a priori’ design provided? No There is no published protocol for this meta-analysis
Systematic literature research Yes Search method is illustrated
Appropriate search strings, data bases and hand search No Only a PubMed search and a hand search were conducted. A very limited search string was used.
At least two reviewers for selecting retrieved studies Unclear The review process, screening abstracts and reading full texts is not
described. Two authors extracted outcome data from each trial independently. The inter observer kappa for trial inclusion was 0.94
Well documented process of selection of included studies (e.g. PRISMA flow diagram) Unclear Some kind of PRISMA flow was used, but the review process is unclear. A list of excluded studies is missing.
Quality of the studies documented and considered for the synthesis of evidence No Quality appraisal of studies is lacking
Was the conflict of interest stated? Yes None declared.
Assessed publication bias No Publication bias not assessed
Heterogeneity statistically analysed Yes X2 tests were used to test heterogeneity
Quality of internal validity Poor No study quality assessment was performed
  1. Legend: RCT randomized controlled trial, ACE angiotensin-converting enzyme, ARB angiotensin-receptor blockers, BB Beta-blockers, CCB calcium channel blockers, FU Follow up, TD Thiazide diuretic