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Table 1 Study characteristics and risk of bias of the 127 included randomized controlled trials

From: Are potentially clinically meaningful benefits misinterpreted in cardiovascular randomized trials? A systematic examination of statistical significance, clinical significance, and authors’ conclusions

Study characteristics  
Journal, n (%)
New England Journal of Medicine 65 (51)
Lancet 23 (18)
Journal of the American Medical Association 20 (16)
British Medical Journal 5 (4)
Annals of Internal Medicine 1 (1)
Circulation 13 (10)
Setting, n
 Community 74 (58)
 Hospital 53 (42)
Primary or secondary prevention, n
 Primary 19 (15)
 Secondary 108 (85)
Experimental interventional, n
 Medication 65 (51)
 Surgery 32 (25)
 Models of care 11 (9)
 Vitamin/supplement 9 (7)
 Lifestyle 4 (3)
 Diagnostics/other* 6 (5)
Patient characteristics
 Median age (interquartile range), years 63.8 (61.5–66.5)
 Percent males (interquartile range) 72.0 (60.4–78.0)
Study size and duration
 Median study size (interquartile range) 3020 (1319–8521)
 Median study duration (interquartile range), months 24.0 (8.3–45.3)
Primary outcome included (median 3, range 1–10), n (%)
 Myocardial infarction 101 (80)
 Stroke 83 (65)
 Cardiovascular death 64 (50)
 Overall death 51 (40)
 Revascularization 31 (25)
 Heart failure 22 (17)
 Othera 37 (29)
Risk of bias, n (%)  
Planned trial duration
 Completed as planned 95 (75)
 Extended 4 (3)
 Stopped for benefit 8 (6)
 Stopped for harm 10 (8)
 Stopped for futility 9 (7)
 Stopped for financial reasons 1 (1)
Allocation concealment
 Yes 98 (77)
 Unclear/no 29 (23)
Blinding
 Double 65 (51)
 Single 13 (10)
 None 49 (39)
Analysis
 Intention to treat 119 (94)
 Modified intention to treat 7 (6)
 Per protocol 1 (1)
Sample size estimation
 Estimation attained 83 (65)
 Estimation missed 38 (30)
 No estimation given 6 (5)
Withdrawal
 Number provided 115 (91)
 Median (interquartile range) 2.3 (0.5–7.0)
Funding
 Industry 52 (41)
 Mixed 46 (36)
 Public 28 (22)
 Not described 1 (1)
  1. *Examples of other include stem cells and continuous positive airway pressure
  2. aOther includes angina, thromboembolism, stent failure, cardiac arrest, renal outcomes, shock, peripheral vascular event, bleeding, arrhythmia, pericardial tamponade, respiratory failure, severe left ventricular dysfunction requiring mechanical support, hypertension, and/or aortic insufficiency