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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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Intervention or exposure

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Review versions

2,325 questions in 216 reviews · Airways

current versions

No studies 249 · 10.7%Ungraded 107 · 4.6%Very low 276 · 11.9%Low 751 · 32.3%Moderate 718 · 30.9%High 224 · 9.6%

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
Selexipag vs placebo Mortality · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	2 studies · 1199 participants	Moderate
Selexipag vs placebo mPAP the higher the mPAP, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	1 study · 43 participants	Moderate
Selexipag vs placebo PVR (the higher the PVR, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	1 study · 43 participants	Moderate
Selexipag vs placebo Cardiac index (the lower the cardiac index, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	1 study · 43 participants	Moderate
Selexipag vs placebo RAP (the lower the RAP, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	1 study · 43 participants	Moderate
Selexipag vs placebo Dyspnoea (lower scores indicates more severe breathlessness) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	1 study · 43 participants	Moderate
Selexipag vs placebo Headache+ · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	2 studies · 1199 participants	High
Prostacyclin vs control 6MWD · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	13 studies · 2283 participants	Low
Prostacyclin vs control Mortality · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	OR 0.6 [0.38, 0.94]	15 studies · 2554 participants	Moderate
Prostacyclin vs control mPAP (the higher the mPAP, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	8 studies · 1132 participants	Low
Prostacyclin vs control PVR (the higher the PVR, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	7 studies · 658 participants	Moderate
Prostacyclin vs control Cardiac index (the lower the cardiac index, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	6 studies · 868 participants	Low
Prostacyclin vs control RAP (the lower the RAP, the worse the pulmonary hypertension) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	6 studies · 1060 participants	Moderate
Prostacyclin vs control Dyspnoea (lower scores indicates more severe breathlessness) · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	8 studies · 1521 participants	Low
Prostacyclin vs control Quality of life · pulmonary arterial hypertension Prostacyclin for pulmonary arterial hypertension (2019) · Cochrane	no estimate extracted	3 studies · 271 participants	Moderate
Once‐daily LABA/LAMA in a combined inhaler vs placebo All‐cause mortality (3‐week to 1‐year · Adults with COPD Once daily long‐acting beta2‐agonists and long‐acting muscarinic antagonists in a combined inhaler versus… (2019) · Cochrane	OR 1.88 [0.81, 4.36]	18 studies · 8752 participants	Low
Once‐daily LABA/LAMA in a combined inhaler vs placebo Serious adverse events (3‐week to 1‐year · Adults with COPD Once daily long‐acting beta2‐agonists and long‐acting muscarinic antagonists in a combined inhaler versus… (2019) · Cochrane	OR 1.06 [0.88, 1.28]	22 studies · 10536 participants	High
Once‐daily LABA/LAMA in a combined inhaler vs placebo Acute exacerbations of COPD (4‐week to 24‐week · Adults with COPD Once daily long‐acting beta2‐agonists and long‐acting muscarinic antagonists in a combined inhaler versus… (2019) · Cochrane	OR 0.53 [0.36, 0.78]	3 studies · 1127 participants	Moderate
Once‐daily LABA/LAMA in a combined inhaler vs placebo Difference vs placebo in adjusted SGRQ score (HRQoL) Scale 0‐100, lower on the scale is better. (12‐week to 1‐year · Adults with COPD Once daily long‐acting beta2‐agonists and long‐acting muscarinic antagonists in a combined inhaler versus… (2019) · Cochrane	no estimate extracted	8 studies · 4952 participants	High
Once‐daily LABA/LAMA in a combined inhaler vs placebo Difference vs placebo in adjusted trough FEV1 at EOT (3‐week to 1‐year · Adults with COPD Once daily long‐acting beta2‐agonists and long‐acting muscarinic antagonists in a combined inhaler versus… (2019) · Cochrane	no estimate extracted	13 studies · 6598 participants	Moderate
Once‐daily LABA/LAMA in a combined inhaler vs placebo Difference vs placebo in adjusted peak FEV1 (3‐week to 6‐month · Adults with COPD Once daily long‐acting beta2‐agonists and long‐acting muscarinic antagonists in a combined inhaler versus… (2019) · Cochrane	no estimate extracted	7 studies · 4188 participants	Moderate
Once‐daily LABA/LAMA in a combined inhaler vs placebo Adverse events (3‐week to 1‐year · Adults with COPD Once daily long‐acting beta2‐agonists and long‐acting muscarinic antagonists in a combined inhaler versus… (2019) · Cochrane	OR 0.95 [0.86, 1.04]	17 studies · 8235 participants	High
Macrolide+tetracycline vs macrolide Quality of life, measured by CRQ (dyspnoea, fatigue, emotional function, and mastery subscales) · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	1 study · 187 participants	Very low
Quinolone vs macrolide All‐cause mortality · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	1 study · 50 participants	Ungraded
Quinolone vs macrolide Quality of life Drug resistance/microbial sensitivity Serious adverse events Lung function Hospitalisations Adverse events/side effects Number of participants colonised with P aeruginosa · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	NR	No studies
Macrolide vs tetracycline Number of participants experiencing one or more exacerbations Macrolide versus tetracycline · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	OR 0.44 [0.14, 1.38]	1 study · 50 participants	Low
Macrolide vs tetracycline All‐cause mortality · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	1 study · 50 participants	Ungraded
Macrolide vs tetracycline Quality of life Drug resistance/microbial sensitivity Serious adverse events Lung function Hospitalisations Adverse events/side effects Number of participants colonised with P aeruginosa · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	NR	No studies
Macrolide+tetracycline vs macrolide All‐cause serious adverse events 60 weeks (end of study) · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	OR 1 [0.52, 1.93]	1 study · 198 participants	Very low
Macrolide+tetracycline vs macrolide Lung function (trough FEV1) Change from baseline to 12 weeks (end of active treatment) · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	1 study · 182 participants	Very low
Macrolide+tetracycline vs macrolide All‐cause mortality 60 weeks (end of study) · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	OR 1.63 [0.38, 7.02]	1 study · 198 participants	Very low
Macrolide+tetracycline vs macrolide Number of people experiencing one or more exacerbations, Drug resistance/microbial sensitivity (as reported by trialists), including emergence of atypical bacteria, Number of participants colonised with Pseudomonas aeruginosa · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	NR	No studies
Quinolone vs tetracycline Number of participants experiencing one or more exacerbations Quinolone versus tetracycline · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	OR 0.44 [0.14, 1.38]	1 study · 50 participants	Low
Quinolone vs tetracycline All‐cause mortality · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	1 study · 50 participants	Ungraded
Quinolone vs tetracycline Quality of life Drug resistance/microbial sensitivity Serious adverse events Lung function Hospitalisations Adverse events/side effects Number of participants colonised with P aeruginosa · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	no estimate extracted	NR	No studies
Quinolone vs macrolide Number of participants experiencing one or more exacerbations Quinolone versus macrolide · chronic obstructive pulmonary disease Head‐to‐head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease (2019) · Cochrane	OR 1 [0.32, 3.1]	1 study · 50 participants	Low
Speech and language therapy vs healthy lifestyle advice Health‐related quality of life · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	MD 1.53 [0.21, 2.85]	1 study · 71 participants	Low
Speech and language therapy vs healthy lifestyle advice Serious adverse events · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	no estimate extracted	1 study · 75 participants	Low
Speech and language therapy vs healthy lifestyle advice Objective cough counts (over 24‐hour period) · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	no estimate extracted	1 study · 71 participants	Low
Speech and language therapy vs healthy lifestyle advice Symptoms · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	no estimate extracted	1 study · 87 participants	Low
Speech and language therapy vs healthy lifestyle advice Clinical improvement (as defined by trialists) · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	OR 48.13 [13.53, 171.25]	1 study · 87 participants	Very low
Speech and language therapy vs healthy lifestyle advice Subjective measures of cough (e.g. VAS/numerical cough scale score) · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	no estimate extracted	1 study · 71 participants	Low
Speech and language therapy vs healthy lifestyle advice Cough reflex sensitivity (as measured by cough challenge: capsaicin concentration required to provoke 5 coughs) · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	no estimate extracted	1 study · 49 participants	Low
Speech and language therapy vs healthy lifestyle advice Adverse events · participants with chronic cough Speech and language therapy for management of chronic cough (2019) · Cochrane	no estimate extracted	1 study · 75 participants	Low
Inhaled corticosteroids vs placebo Lung function (spirometry indices) ‐ FEV1 (in L, end study minus baseline values) · people with bronchiectasis Inhaled corticosteroids for bronchiectasis (2018) · Cochrane	no estimate extracted	2 studies · 156 participants	Low
Inhaled corticosteroids vs placebo Number of participants improved · people with bronchiectasis Inhaled corticosteroids for bronchiectasis (2018) · Cochrane	OR 0.57 [0.24, 1.34]	1 study · 86 participants	Low
Inhaled corticosteroids vs placebo Lung function (spirometry indices) ‐ FVC (in L, end study minus baseline values) · people with bronchiectasis Inhaled corticosteroids for bronchiectasis (2018) · Cochrane	no estimate extracted	2 studies · 156 participants	Low
Inhaled corticosteroids vs placebo Lung function (other indices) ‐ diffusion capacity % predicted (end of study) · people with bronchiectasis Inhaled corticosteroids for bronchiectasis (2018) · Cochrane	no estimate extracted	1 study · 57 participants	Low
Inhaled corticosteroids vs placebo Lung function (other indices) ‐ RV % predicted (end of study values) · people with bronchiectasis Inhaled corticosteroids for bronchiectasis (2018) · Cochrane	no estimate extracted	1 study · 57 participants	Low
Inhaled corticosteroids vs placebo Lung function (other indices) ‐ TLC % predicted (end of study values) · people with bronchiectasis Inhaled corticosteroids for bronchiectasis (2018) · Cochrane	no estimate extracted	1 study · 57 participants	Low