Summary of findings 3. Summary of findings for all doses of nasal decongestant compared to placebo in adults with the common cold.

Should a decongestant (any dose) in monotherapy be used for the common cold in adults?
Patient or population: adult patients with the common cold Settings: common cold centres, universities and hospitals Intervention: single‐dose or multi‐dose decongestant in monotherapy, oral and topical decongestants combined Comparison: placebo Measure of effect: we transformed results from all studies to ensure that higher scores represent better functioning. We standardised results using the standardised mean differences (SMD). As such differences are expressed in standardised units. As a rough guide, a SMD of 0.2 to 0.49 represents a small, 0.5 to 0.79 a moderate and ≥ 0.8 a large clinical effect.
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	№ of participants (studies)	Quality of the evidence (GRADE)	Comments
	Risk with placebo	Risk with all doses of decongestants
Primary outcome: subjective symptom score (mean) ‐ 3 hours after dosing	The unstandardised mean subjective symptom score ranged from ‐2.54 to ‐35.79	Subjective nasal congestion was 0.44 standard units better in the treatment group (95% CI 0.11 to 0.78; P value 0.01)	—	146 (3 RCTs)	⊕⊕⊕⊝ MODERATE 1	Pseudoephedrine (Sperber 1989; Taverner 1999); xylometazoline (Eccles 2008)
Primary outcome: subjective symptom score (mean) ‐ 3 hours after dosing Oral	The unstandardised mean subjective symptom score ranged from ‐2.54 to ‐7	Subjective nasal congestion was 0.33 standard units better in the treatment group (95% CI ‐0.11 to 0.77; P value 0.14)	—	85 (2 RCTs)	⊕⊕⊝⊝ LOW 2 3	Pseudoephedrine (Sperber 1989; Taverner 1999)
Primary outcome: subjective symptom score (mean) ‐ 3 hours after dosing Topical	—	—	—	61 (1 RCT)	—	Insufficient data to pool results Xylometazoline (Eccles 2008)
Primary outcome: subjective symptom score (AUC) ‐ 3 hours after dosing Oral	The unstandardised mean AUC for the subjective symptom score ranged from 22 to ‐77.45	Subjective nasal congestion was 0.11 standard units better in the treatment group (95% CI ‐0.14 to 0.35; P value 0.39)	—	260 (2 RCTs)	⊕⊕⊝⊝ LOW 3 4	None of the included studies that used a topical decongestant reported the AUC for subjective symptoms of congestion Pseudoephedrine (Latte 2004; Latte 2007)
Primary outcome: overall patient well‐being	—	—	—	(0 studies)	—	Not reported
Secondary outcome: All adverse events	Only 2 single‐dose studies reported adverse events. One study reported no events (Taverner 1999, pseudoephedrine) and the other was excluded from meta‐analyses as this was a cross‐over study (Gronborg 1983, norephedrine). Combining single‐dose and multi‐dose studies would not change the results of the multi‐dose analyses.			—	—	—
*The risk in the intervention group (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; AUC: area under the curve; NAR: nasal airway resistance; RCT: randomised controlled trial
GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: 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 quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

¹Downgraded because two studies had unclear risk of bias on five out of seven domains (Eccles 2008; Sperber 1989).

²Downgraded because one study had unclear risk of bias on five out of seven domains (Sperber 1989).

³Downgraded because data came from only two studies.

⁴Downgraded because one study had unclear risk of bias on five out of seven domains (Latte 2007).