Table 2.
Coprimary endpoints and virological secondary endpoint in the intention-to-treat population
| Convalescent plasma group | Placebo group | RR or crude difference (95% CI) | p value | |||
|---|---|---|---|---|---|---|
| Clinical primary end point: hospitalisation within 28 days of random assignment | ||||||
| Overall population | 22/188 (12%) | 21/188 (11%) | RR 1·05 (0·78 to 1·41) | 0·76 | ||
| Subgroups according to serostatus at baseline* | ||||||
| Negative baseline serum antibody status | 20/160 (13%) | 19/166 (11%) | RR 1·09 (0·83 to 1·44) | 0·54 | ||
| Positive baseline serum antibody status | 2/23 (9%) | 2/20 (10%) | RR 0·87 (0·20 to 3·88) | 0·86 | ||
| Subgroups according to duration of illness† | ||||||
| ≤3 days | 4/49 (8%) | 6/52 (12%) | RR 0·83 (0·56 to 1·25) | 0·37 | ||
| >3 days | 18/136 (13%) | 15/135 (11%) | RR 1·19 (0·89 to 1·60) | 0·24 | ||
| Subgroups according to plasma neutralisation activity‡ | ||||||
| ID50 >1:250§ | 13/132 (10%) | 21/188 (11%) | RR 0·88 (0·70 to 1·12) | 0·30 | ||
| ID50 ≤1:250 | 2/16 (13%) | 21/188 (11%) | RR 1·12 (0·77 to 1·63) | 0·56 | ||
| Virological primary and secondary endpoints: change in viral load from baseline¶‖ | ||||||
| Overall population | ||||||
| Day 7 | −2·41 (1·32; 174) | −2·32 (1·43; 174) | −0·10 (−0·35 to 0·15) | 0·42 | ||
| Day 28 | −3·86 (1·56; 180) | −4·00 (1·45; 172) | 0·12 (−0·17 to 0·40) | 0·33 | ||
| Subgroups according to serostatus at baseline* | ||||||
| Negative baseline serum antibody status | ||||||
| Day 7 | −2·54 (1·31; 149) | −2·35 (1·43; 155) | −0·19 (−0·45 to 0·07) | 0·16 | ||
| Day 28 | −4·12 (1·35; 154) | −4·10 (1·37; 154) | −0·02 (−0·28 to 0·25) | 0·89 | ||
| Positive baseline serum antibody status | ||||||
| Day 7 | −1·45 (1·19; 21) | −1·85 (1·42; 17) | 0·29 (−0·54 to 1·12) | 0·49 | ||
| Day 28 | −1·91 (1·60; 22) | −2·97 (1·87; 16) | 0·86 (−0·20 to 1·91) | 0·11 | ||
Data are n/N (%) or mean (SD; N) except where otherwise stated. ID50=50% inhibitory dilution. RR=relative risk.
*
Seven of 376 participants did not have baseline serological test.
†
Four of 376 participants did not have records on duration of illness.
‡
40 of 188 participants in the convalescent plasma group did not have a plasma neutralisation activity test.
§
ID50 value of 1:250 is equivalent to 60 IU/mL (appendix p 5).
¶
28 of 376 participants did not have nasal swab collected on day 7.
‖
24 of 376 participants did not have nasal swab collected on day 28.