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Each row is one question a systematic review asked: who, what, compared with what, and which outcome, with the effect it found and how certain that is. Words match anywhere in the field.

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Review versions

1,554 questions in 140 reviews · Heart

current versions

No studies 272 · 17.5%Ungraded 44 · 2.8%Very low 329 · 21.2%Low 464 · 29.9%Moderate 319 · 20.5%High 126 · 8.1%

Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.

Question	Effect	Evidence	Status / GRADE
Intervention NR Body mass index, change from baseline (kg/m2) · people with primary prevention of cardiovascular disease in Multiple risk factor interventions for primary prevention of cardiovascular disease in low‐ and… (2015) · Cochrane	no estimate extracted	7 studies · 2984 participants	Low
Intervention NR Waist circumference, change from baseline (cm) · people with primary prevention of cardiovascular disease in Multiple risk factor interventions for primary prevention of cardiovascular disease in low‐ and… (2015) · Cochrane	no estimate extracted	4 studies · 393 participants	Moderate
Implantable cardioverter defibrillators vs β‐blocker therapy All‐cause mortality · people with cardiac channelopathies Implantable defibrillators versus medical therapy for cardiac channelopathies (2015) · Cochrane	RR 0.11 [0.01, 0.83]	2 studies · 86 participants	Low
Implantable cardioverter defibrillators vs β‐blocker therapy Fatal and non‐fatal cardiovascular events · people with cardiac channelopathies Implantable defibrillators versus medical therapy for cardiac channelopathies (2015) · Cochrane	RR 1.49 [0.66, 3.34]	2 studies · 86 participants	Low
Implantable cardioverter defibrillators vs β‐blocker therapy Adverse events · people with cardiac channelopathies Implantable defibrillators versus medical therapy for cardiac channelopathies (2015) · Cochrane	RR 2.44 [0.92, 6.44]	2 studies · 86 participants	Low
Implantable cardioverter defibrillators vs β‐blocker therapy Non‐fatal cardiovascular events · people with cardiac channelopathies Implantable defibrillators versus medical therapy for cardiac channelopathies (2015) · Cochrane	RR 11.44 [1.57, 83.36]	2 studies · 86 participants	Low
Implantable cardioverter defibrillators vs β‐blocker therapy Inappropriate ICD firing · people with cardiac channelopathies Implantable defibrillators versus medical therapy for cardiac channelopathies (2015) · Cochrane	RR 10.17 [1.32, 78.54]	2 studies · 86 participants	Low
Low dietary fat vs usual fat Weight, kg (adults) body weight in kg · children, young people and adults from the general population Effects of total fat intake on body weight (2015) · Cochrane	no estimate extracted	30 studies · 53647 participants	High
Heparin vs placebo All‐cause mortality · patients with non‐ST elevation acute coronary syndromes Heparin versus placebo for non‐ST elevation acute coronary syndromes (2014) · Cochrane	RR 0.84 [0.36, 1.98]	6 studies · 2426 participants	Low
Heparin vs placebo Incidence of myocardial infarction · patients with non‐ST elevation acute coronary syndromes Heparin versus placebo for non‐ST elevation acute coronary syndromes (2014) · Cochrane	RR 0.4 [0.25, 0.63]	6 studies · 2426 participants	Low
Heparin vs placebo Recurrent angina · patients with non‐ST elevation acute coronary syndromes Heparin versus placebo for non‐ST elevation acute coronary syndromes (2014) · Cochrane	RR 0.81 [0.6, 1.09]	6 studies · 2426 participants	Very low
Heparin vs placebo Incidence of revascularization procedures · patients with non‐ST elevation acute coronary syndromes Heparin versus placebo for non‐ST elevation acute coronary syndromes (2014) · Cochrane	RR 0.93 [0.76, 1.15]	6 studies · 2520 participants	Low
Heparin vs placebo Major hemorrhage · patients with non‐ST elevation acute coronary syndromes Heparin versus placebo for non‐ST elevation acute coronary syndromes (2014) · Cochrane	RR 2.05 [0.91, 4.6]	8 studies · 3118 participants	Low
Intervention NR Positive serology: RCT data ‐ nitroderivatives Conventional serology, AT and F29 ELISA techniques · people with chronic asymptomatic Trypanosoma cruzi infection Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection (2014) · Cochrane	OR 0.12 [0.03, 0.42]	3 studies · 524 participants	Moderate
Intervention NR Positive PCR: RCT data ‐ benznidazole‐ Children PCR · people with chronic asymptomatic Trypanosoma cruzi infection Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection (2014) · Cochrane	OR 0.51 [0.25, 1.04]	1 study · 129 participants	Moderate
Intervention NR Positive xenodiagnosis: all populations ‐ RCT data ‐ nitroderivatives Xenodiagnosis · people with chronic asymptomatic Trypanosoma cruzi infection Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection (2014) · Cochrane	OR 0.09 [0.04, 0.18]	2 studies · 366 participants	High
Intervention NR Mean reduction of antibodies titres: all populations, all tested drugs Mean change of antibodies · people with chronic asymptomatic Trypanosoma cruzi infection Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection (2014) · Cochrane	no estimate extracted	3 studies · 225 participants	Low
Intervention NR ECG Abnormalities ‐ RCT data ‐ benznidazole · people with chronic asymptomatic Trypanosoma cruzi infection Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection (2014) · Cochrane	OR 0.41 [0.07, 2.31]	2 studies · 235 participants	Low
Intervention NR Progression of cardiomyopathy: non‐RCT data ‐ adults ‐ nitroderivatives Emergence of substantial changes in the diagnostic tests or clinical status, or both (see text) · people with chronic asymptomatic Trypanosoma cruzi infection Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection (2014) · Cochrane	OR 0.74 [0.32, 1.73]	4 studies · 986 participants	Very low
Intervention NR Mortality: non‐RCT data ‐ adults ‐ nitroderivatives All‐cause mortality · people with chronic asymptomatic Trypanosoma cruzi infection Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection (2014) · Cochrane	OR 0.55 [0.26, 1.14]	6 studies · 3396 participants	Very low
Shengmai plus usual treatment vs usual treatment alone Mortality · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	11 studies · 858 participants	Ungraded
Shengmai plus usual treatment vs usual treatment alone Hospitalization/rehospitalization · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	12 studies · 858 participants	Ungraded
Shengmai vs placebo Mortality · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	3 studies · 106 participants	Ungraded
Shengmai vs placebo Lack of improvement in heart failure (NYHA class improved < I class or worsening of heart failure) NYHA classification grading of cardiac function · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	RR 0.22 [0.11, 0.44]	1 study · 40 participants	Low
Shengmai vs placebo Adverse effects · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 2 participants	Ungraded
Shengmai vs placebo Mean change in exercise test (mins) Treadmill exercise test · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 18 participants	Low
Shengmai vs placebo Mean change in ejection fraction (%) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 52 participants	Low
Shengmai vs placebo Mean change in cardiac output (L/min) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 52 participants	Low
Shengmai vs placebo Mean change in cardiac index (L/min*m²) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 80 participants	Low
Shengmai vs placebo Mean change in ECG: Q‐Z · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 80 participants	Low
Shengmai vs placebo Hospitalization/ rehospitalization · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	3 studies · 106 participants	Ungraded
Shengmai plus usual treatment vs usual treatment alone Lack of improvement in heart failure (NYHA class improved < I class or worsening of heart failure) NYHA classification grading of cardiac function · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	RR 0.37 [0.26, 0.51]	10 studies · 672 participants	Low
Shengmai plus usual treatment vs usual treatment alone Adverse effects · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	2 studies · 4 participants	Ungraded
Shengmai plus usual treatment vs usual treatment alone Mean exercise tolerance test (after treatment) (min) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 60 participants	Low
Shengmai plus usual treatment vs usual treatment alone Mean change in quality of life Minnesota Living with Heart Failure Questionnaire (MLWHF) score · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	1 study · 60 participants	Low
Shengmai plus usual treatment vs usual treatment alone Mean change in ejection fraction (%) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	4 studies · 354 participants	Very low
Shengmai plus usual treatment vs usual treatment alone Mean change in cardiac output (L/min) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	4 studies · 360 participants	Very low
Shengmai plus usual treatment vs usual treatment alone Mean change in stroke volume (mL) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	3 studies · 240 participants	Very low
Shengmai plus usual treatment vs usual treatment alone Change in cardiac index (L/min*m²) · patients with heart failure Shengmai (a traditional Chinese herbal medicine) for heart failure (2014) · Cochrane	no estimate extracted	2 studies · 160 participants	Very low
Statins vs control at 4 months (3 to 6 months) Combined outcome of non‐fatal myocardial infarction, non‐fatal stroke, and total number of deaths · patients with acute coronary syndrome Statins for acute coronary syndrome (2014) · Cochrane	RR 0.93 [0.81, 1.06]	11 studies · 9625 participants	Moderate
Statins vs control at 4 months (3 to 6 months) Death from all causes · patients with acute coronary syndrome Statins for acute coronary syndrome (2014) · Cochrane	RR 0.9 [0.7, 1.14]	12 studies · 9733 participants	Moderate
Statins vs control at 4 months (3 to 6 months) Fatal and non‐fatal myocardial infarction or reinfarction · patients with acute coronary syndrome Statins for acute coronary syndrome (2014) · Cochrane	RR 0.91 [0.77, 1.06]	10 studies · 9537 participants	Moderate
Statins vs control at 4 months (3 to 6 months) Fatal and non‐fatal stroke · patients with acute coronary syndrome Statins for acute coronary syndrome (2014) · Cochrane	RR 0.72 [0.45, 1.16]	7 studies · 8536 participants	Moderate
Statins vs control at 4 months (3 to 6 months) Unstable angina · patients with acute coronary syndrome Statins for acute coronary syndrome (2014) · Cochrane	RR 0.76 [0.59, 0.96]	9 studies · 8770 participants	Moderate
Statins vs control at 4 months (3 to 6 months) Acute heart failure · patients with acute coronary syndrome Statins for acute coronary syndrome (2014) · Cochrane	RR 0.86 [0.65, 1.15]	2 studies · 7583 participants	Moderate
Statins vs control at 4 months (3 to 6 months) Rhabdomyolysis · patients with acute coronary syndrome Statins for acute coronary syndrome (2014) · Cochrane	RR 6.9 [0.36, 133.47]	1 study · 4497 participants	Low
Pre‐hospital vs in‐hospital thrombolysis All‐cause hospital mortality · participants with ST‐elevation myocardial infarction Pre‐hospital versus in‐hospital thrombolysis for ST‐elevation myocardial infarction (2014) · Cochrane	RR 0.73 [0.37, 1.41]	3 studies · 538 participants	Low
Pre‐hospital vs in‐hospital thrombolysis Time to thrombolytic treatment [minutes] · participants with ST‐elevation myocardial infarction Pre‐hospital versus in‐hospital thrombolysis for ST‐elevation myocardial infarction (2014) · Cochrane	no estimate extracted	2 studies · 438 participants	High
Pre‐hospital vs in‐hospital thrombolysis Acute myocardial infarction functional outcomes ‐ ejection fraction [percentage] · participants with ST‐elevation myocardial infarction Pre‐hospital versus in‐hospital thrombolysis for ST‐elevation myocardial infarction (2014) · Cochrane	no estimate extracted	2 studies · 416 participants	Low
Pre‐hospital vs in‐hospital thrombolysis Adverse effects ‐ ventricular Fribrillation · participants with ST‐elevation myocardial infarction Pre‐hospital versus in‐hospital thrombolysis for ST‐elevation myocardial infarction (2014) · Cochrane	RR 2.73 [0.68, 10.86]	2 studies · 178 participants	Low