Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Risk of bias and number of participants for the included trials
| High | Unclear | Low | No RoB | |
|---|---|---|---|---|
|
Number of trials (total = 1659; % based on 1640 trials with risk of bias information) |
1013 (62%) | 494 (30%) | 133 (8%) | 19 |
|
Number of participants (total = 398,410) |
222,850 (55.93%) | 127,290 (31.95%) | 47,138 (11.83%) | 1132 (0.28%) |
