Summary of findings 6. Hypertonic saline compared with mannitol for cystic fibrosis.

Hypertonic saline compared with mannitol for cystic fibrosis
Patient or population: adults and children with cystic fibrosis Settings: outpatients Intervention: hypertonic saline Comparison: mannitol
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No of participants (trials)	Certainty of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Mannitol	Hypertonic saline
FEV1: short‐term   Follow‐up: up to 95 minutes	See comment.		NA	12 (1 trial)	⊕⊝⊝⊝ very lowa,b,c	Trial had cross‐over design. FEV1 was assessed in the included trial at 5 minutes and 95 minutes postintervention. These very short‐term time‐points are not of clinical relevance to this review. Change from baseline within‐groups was reported but no between‐group data.
FEV1: long‐term	Outcome not reported.
LCI	Outcome not reported.
Mortality	Outcome not reported.
Measures of sputum clearance   Follow‐up: up to 95 minutes	There was no significant difference between treatment groups for matched voluntary cough.		NA	12 (1 trial)	⊕⊝⊝⊝ very lowa,b,d	Trial had cross‐over design.
Pulmonary exacerbations	Outcome not reported.
Adverse events   Follow‐up: up to 95 minutes	See comment.		NA	12 (1 trial)	⊕⊝⊝⊝ very lowa,b,d	Trial had cross‐over design. Mannitol was considered to be a more 'irritating' treatment than other treatments (4‐armed trial); no specific data given.
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; FEV1: forced expiratory volume in 1 second; LCI: lung clearance index; NA: not applicable.
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

^aDowngraded once due to risk of bias: high risk of detection bias as participants could discern the taste of the intervention and no washout period was used.
^bDowngraded once due to applicability: results apply only to those who can tolerate hypertonic saline, and the trial included only participants over the age of 16 so results may not apply to younger children.
^cDowngraded once due to applicability: the outcome measured only at very short‐term time points (minutes after intervention), which are not of clinical relevance to this review.
^dDowngraded once due to imprecision: no numerical data provided and small sample size.