TABLE 6.

Summary of findings: Aspirin compared to Placebo/Other NSAIDs for adult ARTI

Patient or population: adult ARTI Intervention: Aspirin Comparison: Placebo/Other NSAIDs
Outcome № of participants (studies)	Relative effect (95% CI)	Anticipated absolute effects (95% CI)			Certainty	What happens
				Difference
Fever follow up: range single dose to 4 days № of participants: 186 (2 RCTs)	–	not pooled	–	not pooled	⨁⨁⨁◯ MODERATE a	Aspirin results in a large reduction in fever.
Cough follow up: 4 days № of participants: 23 (1 RCT)	RR 3.90 (0.47 to 32.09)	7.7%	30.0% (3.6 to 100)	22.3% more (4.1 fewer to 239.2 more)	⨁◯◯◯ VERY LOW b,c	Aspirin may have little to no effect on cough but the evidence is very uncertain.
Sore Throat follow up: range 6 hours to 4 days № of participants: 905 (5 RCTs)	‐	not pooled	‐	not pooled	⨁⨁⨁◯ MODERATE d,e	Aspirin likely results in a slight reduction in sore throat pain.
ARDS № of participants: 390 (1 RCT)	RR 1.1765 (0.6358 to 2.1768)	8.7%	10.3% (5.5 to 19)	1.5% more (3.2 fewer to 10.3 more)	⨁⨁⨁◯ MODERATE f	Aspirin did not decrease ARDS in a single study by Kor et al.
Length Of Stay № of participants: 390 (1 RCT)	–	The mean length Of Stay was 0 days	–	mean 0.2 days fewer (1.8114 fewer to 2.2114 more)	⨁⨁⨁◯ MODERATE g	Aspirin resulted in little to no difference in Hospital length Of Stay in a single study by Kor et al.
Mortality № of participants: 390 (1 RCT)	RR 1.00 (0.49 to 2.04)	7.2%	7.2% (3.5 to 14.6)	0.0% fewer (3.7 fewer to 7.5 more)	⨁⨁⨁◯ MODERATE h	Aspirin results in little to no difference in mortality.
Gastrointestinal Adverse Events follow up: range 1 dose to 4 days № of participants: 1248 (6 RCTs)	RR 1.54 (0.92 to 2.60)	3.7%	5.7% (3.4 to 9.5)	2.0% more (0.3 fewer to 5.9 more)	⨁⨁◯◯ LOW i	Gastrointestinal adverse events were not found to be statistically different between groups, but the Aspirin group tended to experience more events

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

Explanations: a. Allocation concealment of studies poses a high risk of bias; outcome assessment was unclear in both studies; b. methods of randomization and blinding are not explained. study protocols are not available to assess the completeness of outcome reporting; c. A Small number of participants; d. 2 out of 5 studies lack explanation on randomization and concealment protocols. On the contrary, the remaining 3, make up the majority of the sample population and are well conducted; e. Although Voelker et al. and Eccles 2013 et al. report a moderate effect on a sore throat, the rest of the studies report little to no effect; f. the Confidence Interval on the relative risk suggests both a moderate reduction and an increase in the incidence of ARDS; g. the effect estimate includes a wide range of effects, both increase and reduce in LOS; h. ARDS patients are not confined to viral pneumonia and i. Both large positive and negative effects with wide confidence intervals are reported.

Abbreviations: CI, Confidence interval; RR, Risk ratio.

^* 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).