Summary of findings 3. Summary of Findings Table ‐ Convalescent plasma compared to placebo or standard care alone for individuals with mild disease.
| Convalescent plasma compared to placebo or standard care alone for individuals with mild disease | ||||||
| Patient or population: individuals with mild disease Setting: Intervention: convalescent plasma Comparison: placebo or standard care alone | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo or standard care alone | Risk with convalescent plasma | |||||
| All‐cause mortality | 50 per 1,000 | 25 per 1,000 (5 to 133) | RR 0.50 (0.09 to 2.65) | 160 (1 RCT) | ⊕⊝⊝⊝ VERY LOW a,b | We are very uncertain about the effect of convalescent plasma on all‐cause mortality. |
| Development of severe clinical COVID‐19 symptoms assessed with: WHO Clinical Progression Scale ≥ 6 | We did not identify any study reporting development of severe clinical COVID‐19 symptoms, when assessed according to WHO Clinical Progression Scale. One study (reporting on 160 participants) reported the need for invasive mechanical ventilation (RR 0.50, 95% CI 0.09 to 2.65, estimated absolute effect with convalescent plasma: 25 of 1000), the risk for developing severe respiratory disease (RR 0.52, 95% CI 0.29 to 0.94, estimated absolute effect with convalescent plasma: 313 of 1000), or critical illness with life‐threatening disease (RR 0.83, 95% CI 0.27 to 2.62, estimated absolute effect with convalescent plasma: 63 of 1000) c,d,e | 160 (1 RCT) | ⊕⊕⊝⊝ LOW b | We are uncertain about the effect of convalescent plasma on developing severe clinical COVID‐19 symptoms. | ||
| Quality of life, assessed with standardised scales at longest follow‐up | not pooled | not pooled | ‐ | (0 studies) | ‐ | We did not identify any study reporting this outcome. |
| Grade 3 and 4 adverse events | We did not identify any study reporting grade 3 or 4 adverse events. One study (reporting on 160 participants) reported that no "solicited" adverse events were observed in any group. | 160 (1 RCT) | ⊕⊝⊝⊝ VERY LOW f,g | We do not know whether convalescent plasma is asscociated with a higher risk of grade 3 or 4 adverse events. | ||
| Serious adverse events | We did not identify any study reporting serious adverse events. One study (reporting on 160 participants) reported that no serious "solicited" adverse events were observed in any group. | 160 (1 RCT) | ⊕⊝⊝⊝ VERY LOW f,g | We do not know whether convalescent plasma is associated with a higher risk of serious adverse events. | ||
| *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). CI: Confidence interval; RR: Risk ratio; SMD: Standardised mean difference | ||||||
| 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 | ||||||
| See interactive version of this table: https://gdt.gradepro.org/presentations/#/isof/isof_question_revman_web_423575913930302502. | ||||||
a. Downgraded one level for serious indirectness, because outcome definition did not exactly match our definition (defined as death associated with COVID‐19); and because all patients were admitted to hospital after recruitment b. Downgraded two levels for very serious imprecision, because CI includes zero effect line, few events, and few participants c. Severe respiratory disease defined as a respiratory rate of 30 breaths per minute or more, an oxygen saturation of less than 93% while the person was breathing ambient air, or both. d. Life‐threatening respiratory disease defined as oxygen supplementation at a fraction of inspired oxygen of 100%, noninvasive or invasive ventilation, admission to an intensive care unit, or any combination of these e. Critical systemic illness defined as respiratory failure with a ratio of the partial pressure of oxygen to Fio2 ≤200 mmHg, shock, multiple organ dysfunction syndrome, or any combination of these f. Downgraded one level for serious indirectness, because outcome definition did not match our definition g. Downgraded two levels for very serious imprecision, because of few participants and only one study was identified