Table 3. Biases reported.
| Type of Bias | N (Number of studies) | % |
|---|---|---|
| Missing data | 26 | 87% |
| Attrition rate | - | 18–65% |
| Described attrition | 19 | 63% |
| Corrected attrition | 12 | 40% |
| Analysis of attrition | 14 | 47% |
| Selection bias | 10 | 33% |
| Sensitivity Analysis | 13 | 43% |
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.