BACKGROUND Evidence supporting convalescent plasma (CP), one of the first investigational treatments for coronavirus disease 2019 (COVID-19), has been inconclusive, leading to conflicting recommendations. The primary objective was to perform a comparative effectiveness study of CP for all-cause, in-hospital mortality in patients with COVID-19.METHODS The multicenter, electronic health records–based, retrospective study included 44,770 patients hospitalized with COVID-19 in one of 176 HCA Healthcare–affiliated community hospitals. Coarsened exact matching (1:k) was employed, resulting in a sample of 3774 CP and 10,687 comparison patients.RESULTS Examination of mortality using a shared frailty model, controlling for concomitant medications, date of admission, and days from admission to transfusion, demonstrated a significant association of CP with lower mortality risk relative to the comparison group (adjusted hazard ratio [aHR] = 0.71; 95% CI, 0.59–0.86; P < 0.001). Examination of patient risk trajectories, represented by 400 clinico-demographic features from our real-time risk model (RTRM), indicated that patients who received CP recovered more quickly. The stratification of days to transfusion revealed that CP within 3 days after admission, but not within 4 to 7 days, was associated with a significantly lower mortality risk (aHR = 0.53; 95% CI, 0.47–0.60; P < 0.001). CP serology level was inversely associated with mortality when controlling for its interaction with days to transfusion (HR = 0.998; 95% CI, 0.997–0.999; P = 0.013), yet it did not reach univariable significance.CONCLUSIONS This large, diverse, multicenter cohort study demonstrated that CP, compared with matched controls, is significantly associated with reduced risk of in-hospital mortality. These observations highlight the utility of real-world evidence and suggest the need for further evaluation prior to abandoning CP as a viable therapy for COVID-19.FUNDING This research was supported in whole by HCA Healthcare and/or an HCA Healthcare–affiliated entity, including Sarah Cannon and Genospace.
Shanna A. Arnold Egloff, Angela Junglen, Joseph S.A. Restivo, Marjorie Wongskhaluang, Casey Martin, Pratik Doshi, Daniel Schlauch, Gregg Fromell, Lindsay E. Sears, Mick Correll, Howard A. Burris III, Charles F. LeMaistre