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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

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
Inhaled mannitol vs placebo Hospitalisations Number of participants experiencing one of more hospitalisations. · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	RR 0.61 [0.34, 1.09]	1 study · 461 participants	Moderate
Inhaled mannitol vs placebo Adverse events · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	OR 0.96 [0.61, 1.51]	2 studies · 804 participants	Moderate
Inhaled mannitol vs placebo Mortality · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	no estimate extracted	NR	No studies
Inhaled mannitol vs placebo Health‐related quality of life measured on the SGRQ Scale from 0 to 100. Low on the scale is better. · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	no estimate extracted	3 studies · 840 participants	Moderate
Inhaled mannitol vs placebo Symptoms Bronchiectasis Symptoms Questionnaire · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	no estimate extracted	1 study · 343 participants	Moderate
Inhaled mannitol vs placebo Lung function FEV1 (L) · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	MD 0.03	1 study · 343 participants	Moderate
Hypertonic saline vs isotonic saline Frequency and duration of exacerbations · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	no estimate extracted	2 studies · 70 participants	Ungraded
Hypertonic saline vs isotonic saline Hospitalisations · patients with bronchiectasis Inhaled hyperosmolar agents for bronchiectasis (2014) · Cochrane	no estimate extracted	1 study · 40 participants	Ungraded
LABA + ICS vs LTRA + ICS Participants with one or more exacerbations requiring systemic corticosteroids · patients with chronic asthma Addition to inhaled corticosteroids of long‐acting beta₂‐agonists versus anti‐leukotrienes for chronic asthma (2014) · Cochrane	RR 0.87 [0.76, 0.99]	8 studies · 6257 participants	High
LABA + ICS vs LTRA + ICS Morning PEFR: L/min change from baseline · patients with chronic asthma Addition to inhaled corticosteroids of long‐acting beta₂‐agonists versus anti‐leukotrienes for chronic asthma (2014) · Cochrane	no estimate extracted	11 studies · 6161 participants	Moderate
LABA + ICS vs LTRA + ICS FEV1: L change from baseline · patients with chronic asthma Addition to inhaled corticosteroids of long‐acting beta₂‐agonists versus anti‐leukotrienes for chronic asthma (2014) · Cochrane	no estimate extracted	10 studies · 4999 participants	High
LABA + ICS vs LTRA + ICS Rescue‐free days: % change from baseline · patients with chronic asthma Addition to inhaled corticosteroids of long‐acting beta₂‐agonists versus anti‐leukotrienes for chronic asthma (2014) · Cochrane	no estimate extracted	5 studies · 2612 participants	Moderate
LABA + ICS vs LTRA + ICS Rescue medication use: puffs/d change from baseline · patients with chronic asthma Addition to inhaled corticosteroids of long‐acting beta₂‐agonists versus anti‐leukotrienes for chronic asthma (2014) · Cochrane	no estimate extracted	7 studies · 4055 participants	High
LABA + ICS vs LTRA + ICS Withdrawals for any reason · patients with chronic asthma Addition to inhaled corticosteroids of long‐acting beta₂‐agonists versus anti‐leukotrienes for chronic asthma (2014) · Cochrane	RR 0.84 [0.74, 0.96]	13 studies · 6960 participants	Moderate
LABA + ICS vs LTRA + ICS Serious adverse events · patients with chronic asthma Addition to inhaled corticosteroids of long‐acting beta₂‐agonists versus anti‐leukotrienes for chronic asthma (2014) · Cochrane	RR 1.33 [0.99, 1.79]	9 studies · 6288 participants	Moderate
Subcutaneous omalizumab + steroid vs placebo + steroid (stable steroid) Number of participants with at least one exacerbation All asthmatic participants (16 to 60 weeks) · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 0.55 [0.46, 0.65]	10 studies · 3261 participants	Moderate
Subcutaneous omalizumab + steroid vs placebo + steroid (stable steroid) Number of participants with at least one exacerbation Moderate to severe asthma (16 to 60 weeks) · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 0.5 [0.42, 0.6]	7 studies · 2889 participants	Moderate
Subcutaneous omalizumab + steroid vs placebo + steroid (stable steroid) Number of participants with at least one exacerbation Severe asthma (16 to 32 weeks) · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 1 [0.5, 1.99]	2 studies · 277 participants	Low
Subcutaneous omalizumab + steroid vs placebo + steroid (stable steroid) Mortality 16 to 60 weeks · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 0.19 [0.02, 1.67]	9 studies · 4245 participants	Low
Subcutaneous omalizumab + steroid vs placebo + steroid (stable steroid) Hospitalisations 28 to 60 weeks · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 0.16 [0.06, 0.42]	4 studies · 1824 participants	Moderate
Subcutaneous omalizumab + steroid vs placebo + steroid (stable steroid) Adverse event—serious 16 to 60 weeks · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 0.72 [0.57, 0.91]	15 studies · 5713 participants	Moderate
Subcutaneous omalizumab + steroid vs placebo + steroid (steroid reduction) Number of participants achieving complete inhaled steroid withdrawal 28 to 32 weeks · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 2.5 [2, 3.13]	4 studies · 1634 participants	Low
Subcutaneous omalizumab + steroid vs placebo + steroid (steroid reduction) >50% reduction in inhaled steroid usage 28 to 32 weeks · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 2.5 [2.02, 3.1]	4 studies · 1634 participants	Moderate
Subcutaneous omalizumab + steroid vs placebo + steroid (steroid reduction) Exacerbations requiring hospitalisation 28 weeks · adults and children with asthma Omalizumab for asthma in adults and children (2014) · Cochrane	OR 0.11 [0.03, 0.48]	3 studies · 1405 participants	Moderate
Intervention NR Clinical failure—primary outcome (by intention‐to‐treat analysis) · children with chronic cough of unknown origin lasting longer than 4 weeks Clinical pathways for chronic cough in children (2014) · Cochrane	OR 0.35 [0.21, 0.58]	1 study · 272 participants	Moderate
Intervention NR PC‐QOL mean score at 6 weeks PC‐QOL is a 27‐item questionnaire. Each question has a 7‐point score ranging from 1 (worst quality of life) to 7 (best quality of life). Scores for each item were added and the average taken · children with chronic cough of unknown origin lasting longer than 4 weeks Clinical pathways for chronic cough in children (2014) · Cochrane	no estimate extracted	1 study · 226 participants	Moderate
Intervention NR Duration of cough post randomisation · children with chronic cough of unknown origin lasting longer than 4 weeks Clinical pathways for chronic cough in children (2014) · Cochrane	no estimate extracted	1 study · 226 participants	Moderate
Intervention NR Proportion of adverse events experienced · children with chronic cough of unknown origin lasting longer than 4 weeks Clinical pathways for chronic cough in children (2014) · Cochrane	no estimate extracted	NR	Moderate
Intervention NR Proportions of participants experiencing adverse events or complications · children with chronic cough of unknown origin lasting longer than 4 weeks Clinical pathways for chronic cough in children (2014) · Cochrane	no estimate extracted	NR	Moderate
Intervention NR Average FEV1 % predicted value · adults and children with asthma Written emotional disclosure for asthma (2014) · Cochrane	no estimate extracted	4 studies · 286 participants	Very low
Intervention NR Average FVC value · adults and children with asthma Written emotional disclosure for asthma (2014) · Cochrane	no estimate extracted	2 studies · 197 participants	Low
Intervention NR Quality of life: Marks Asthma Quality of Life Questionnaire · adults and children with asthma Written emotional disclosure for asthma (2014) · Cochrane	no estimate extracted	1 study · 108 participants	Low
Intervention NR Asthma symptoms · adults and children with asthma Written emotional disclosure for asthma (2014) · Cochrane	no estimate extracted	2 studies · 166 participants	Low
Intervention NR Asthma control · adults and children with asthma Written emotional disclosure for asthma (2014) · Cochrane	SMD 0.29 [0.01, 0.58]	2 studies · 194 participants	Low
Intervention NR Beta agonist use; puffs/d · adults and children with asthma Written emotional disclosure for asthma (2014) · Cochrane	no estimate extracted	1 study · 117 participants	Low
Intervention NR Asthma distress; Asthma Bother Profile · adults and children with asthma Written emotional disclosure for asthma (2014) · Cochrane	no estimate extracted	1 study · 101 participants	Low
Non‐invasive ventilation during exercise training vs exercise training alone or exercise training with sham non‐invasive ventilation Exercise capacity: percentage change in peak work rate Incremental cycle or incremental treadmill test · people with chronic obstructive pulmonary disease Non‐invasive ventilation during exercise training for people with chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	3 studies · 60 participants	Low
Non‐invasive ventilation during exercise training vs exercise training alone or exercise training with sham non‐invasive ventilation Exercise capacity: percentage change constant work rate endurance time Constant work rate cycle endurance test · people with chronic obstructive pulmonary disease Non‐invasive ventilation during exercise training for people with chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	2 studies · 48 participants	Low
Non‐invasive ventilation during exercise training vs exercise training alone or exercise training with sham non‐invasive ventilation Exercise capacity: endurance time (minutes) Constant work rate cycle endurance test · people with chronic obstructive pulmonary disease Non‐invasive ventilation during exercise training for people with chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	2 studies · 48 participants	Low
Non‐invasive ventilation during exercise training vs exercise training alone or exercise training with sham non‐invasive ventilation Health‐related quality of life Change in total score of St George's Respiratory Questionnaire. Scale from 0 to 100 · people with chronic obstructive pulmonary disease Non‐invasive ventilation during exercise training for people with chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	2 studies · 48 participants	Moderate
Non‐invasive ventilation during exercise training vs exercise training alone or exercise training with sham non‐invasive ventilation Physical activity: not measured · people with chronic obstructive pulmonary disease Non‐invasive ventilation during exercise training for people with chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	NR	No studies
Non‐invasive ventilation during exercise training vs exercise training alone or exercise training with sham non‐invasive ventilation Training intensity: fInal training session (% baseline peak work capacity) · people with chronic obstructive pulmonary disease Non‐invasive ventilation during exercise training for people with chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	3 studies · 67 participants	Moderate
Non‐invasive ventilation during exercise training vs exercise training alone or exercise training with sham non‐invasive ventilation Physiological outcomes: isoload blood lactate (mmol/L) · people with chronic obstructive pulmonary disease Non‐invasive ventilation during exercise training for people with chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	2 studies · 37 participants	Moderate
Tiotropium vs placebo Quality of life (SGRQ) Scale 0 to 100, where 100 represents worst possible health status and 0 indicates best possible health status · people with COPD who have smoked for ≥ 10 pack‐years Tiotropium versus placebo for chronic obstructive pulmonary disease (2014) · Cochrane	no estimate extracted	9 studies · 13034 participants	High
Tiotropium vs placebo Number of patients with a clinically significant improvement (≥ 4 units) in quality of life (SGRQ) · people with COPD who have smoked for ≥ 10 pack‐years Tiotropium versus placebo for chronic obstructive pulmonary disease (2014) · Cochrane	OR 1.52 [1.38, 1.68]	9 studies · 11672 participants	High
Tiotropium vs placebo Number of patients with a clinically significant worsening (≥ 4 units) in quality of life (SGRQ) · people with COPD who have smoked for ≥ 10 pack‐years Tiotropium versus placebo for chronic obstructive pulmonary disease (2014) · Cochrane	OR 0.65 [0.59, 0.72]	9 studies · 11672 participants	High
Tiotropium vs placebo Number of patients with one or more exacerbations · people with COPD who have smoked for ≥ 10 pack‐years Tiotropium versus placebo for chronic obstructive pulmonary disease (2014) · Cochrane	OR 0.78 [0.7, 0.87]	22 studies · 23309 participants	High
Tiotropium vs placebo Number of patients with one or more exacerbations requiring hospitalisation · people with COPD who have smoked for ≥ 10 pack‐years Tiotropium versus placebo for chronic obstructive pulmonary disease (2014) · Cochrane	OR 0.85 [0.72, 1]	21 studies · 22852 participants	Moderate
Tiotropium vs placebo Number of patients with one or more hospitalisations for any cause · people with COPD who have smoked for ≥ 10 pack‐years Tiotropium versus placebo for chronic obstructive pulmonary disease (2014) · Cochrane	OR 1 [0.88, 1.13]	19 studies · 20963 participants	Moderate
Tiotropium vs placebo Mortality · people with COPD who have smoked for ≥ 10 pack‐years Tiotropium versus placebo for chronic obstructive pulmonary disease (2014) · Cochrane	OR 0.98 [0.86, 1.11]	22 studies · 23309 participants	Moderate