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Results of controls included in studies in PRS (years: 2010–2011)
| Type Control Used | n |
|---|---|
| Historical control | 2 |
| Concurrent control | 61 |
| Different treatment control | 40 |
| No treatment control | 9 |
| Subjects as self-control | 3 |
| More than one control group | 9 |
n- Number of studies
