Skip to main content
. 2023 Jul 25;2023(7):CD015078. doi: 10.1002/14651858.CD015078

Summary of findings 1. Antiplatelets in hospitalised adults with moderate to severe COVID‐19.

Antiplatelets (plus standard care) compared to standard care (with/without placebo) in hospitalised adults with COVID‐19 (moderate to severe disease)
Patient or population: hospitalised adults with COVID‐19 (moderate to severe disease)
Setting: inpatients
Intervention: antiplatelets (plus standard care)
Comparison: standard care (with/without placebo)
Outcomes Estimated absolute effectsa (95% CI) Relative effect(95% CI) № of participants (studies) Certainty of the evidence(GRADE) Comments
Risk with standard care (with/without placebo) Risk with antiplatelets (plus standard care)
28‐day all‐cause mortality 177 per 1000 168 per 1000 (151 to 186) RR 0.95
(0.85 to 1.05
17,249b,c
(3 RCTs)
⊕⊕⊕⊖
Moderated
Antiplatelets probably result in little to no difference in mortality up to day 28.
Worsening up to day 28: participants with new need for invasive mechanical ventilation or death 230 per 1000 218 per 1000 (207 to 232) RR 0.95
(0.90 to 1.01)
15,266
(2 RCTs)
⊕⊕⊕⊖
Moderated
Antiplatelets probably result in little to no difference in worsening up to day 28.
Improvement up to day 28: participants discharged alive 743 per 1000 743 per 1000 (714 to 773) RR 1.00
(0.96 to 1.04)
15,454
(2 RCTs)
⊕⊕⊕⊖
Moderated
Antiplatelets probably result in little to no difference in improvement up to day 28.
Thrombotic events at longest follow‐up* 57 per 1000 52 per 1000
(46 to 58)
RR 0.90
(0.80 to 1.02)
17,518
(4 RCTs)
⊕⊕⊕⊖
Moderated
Antiplatelets probably result in a slight reduction in thrombotic events.
Serious adverse events at longest follow‐up** 5 per 1000 7 per 1000
(2 to 24) Peto OR 1.57
(0.48 to 5.14)
1815
(1 RCT)
⊕⊕⊖⊖
Lowe
Antiplatelets may result in a slight increase in serious adverse events.
Adverse events during study treatment Not reported We did not identify any study reporting this outcome.
Major bleeding events at longest follow‐up*** 10 per 1000 16 per 1000
(12 to 21) Peto OR 1.68
(1.29 to 2.19)
17,527
(4 RCTs)
⊕⊕⊕⊖
Moderated
Antiplatelets probably increase the occurrence of major bleeding events.
CI: confidence interval; COVID‐19: coronavirus disease 2019; OR: odds ratio, RCT: randomised controlled trial, RR: risk ratio
GRADE Working Group grades of evidenceHigh 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.

aThe risk in the control group was assumed from the pooled effects of the control group from included studies; the intervention risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
bAdditionally, there was a study with 292 participants reporting all‐cause mortality at longest follow‐up (RR 1.11, 95% CI 0.75 to 1.64) (Bohula 2022 (COVID‐PACT)). We did not include this study in the meta‐analysis due to an unclear duration of follow‐up and high risk of bias.
cREMAP‐CAP 2022 reported 180‐day mortality in a second publication. Treatment with antiplatelets may result in little to no difference in 180‐day mortality (RR 0.97, 95% CI 0.82 to 1.15; 1,312 participants; low‐certainty evidence).
dDowngraded one level for serious risk of bias: in Horby 2021 (RECOVERY), an open‐label study, 10% in the intervention group did not receive acetylsalicylic acid; in the open‐label study Bohula 2022 (COVID‐PACT), where 30% in the intervention group discontinued the intervention, the co‐intervention (therapeutic or prophylactic anticoagulation) showed a high level of discontinuation or cross‐over.
eDowngraded two levels for very serious imprecision: only one out of three studies contributed data, with very low event rates and a very wide CI.

*The time frames for 'the longest follow‐up' were 28 days (Berger 2022; Bohula 2022 (COVID‐PACT); Horby 2021 (RECOVERY)) or unclear (REMAP‐CAP 2022).

**The time frames for 'the longest follow‐up' were reported for up to 28 days in three studies (Berger 2022; Horby 2021 (RECOVERY); REMAP‐CAP 2022).

***The time frames for 'the longest follow‐up' were reported for up to 28 days in three studies (Berger 2022; Horby 2021 (RECOVERY)). The longest follow‐up in REMAP‐CAP 2022 for major bleeding was 14 days.