J Infect Dis. 2021 Jun 21:jiab330. doi: 10.1093/infdis/jiab330. Online ahead of print.
BACKGROUND: Early convalescent plasma transfusion may reduce mortality in patients with non-severe coronavirus disease 2019 (COVID-19).
METHODS: This study emulates a (hypothetical) target trial using observational data from a cohort of United States Veterans admitted to a Department of Veterans Affairs (VA) facility between May 1 and November 17, 2020 with non-severe COVID-19. The intervention was convalescent plasma initiated within 2 days of eligibility. Thirty-day mortality was compared using cumulative incidence curves, risk differences, and hazard ratios estimated from pooled logistic models with inverse probability weighting to adjust for confounding.
RESULTS: Of 11,269 eligible person-trials contributed by 4,755 patients, 402 trials were assigned to the convalescent plasma group. Forty and 671 deaths occurred within the plasma and non-plasma groups, respectively. The estimated 30-day mortality risk was 6.5% (95% CI: 4.0, 9.7) in the plasma group and 6.2% (95% CI: 5.6, 7.0) in the non-plasma group. The associated risk difference was 0.30% (95% CI -2.30, 3.60) and the hazard ratio was 1.04 (95% CI 0.64,1.62).
CONCLUSION: Our target trial emulation estimated no meaningful differences in 30-day mortality between non-severe COVID-19 patients treated and untreated with convalescent plasma.