| Proposition | Proposition-specific search, n studies | No. of studies meeting inclusion criteria | Type of evidence* |
| 1 | 2699 | 34 | Circumstantial |
| 2 | 556 | 16 | Partially direct |
| 3 | 464 | 29 | Circumstantial |
| 4 | 131 | 4 | Circumstantial |
| 5 | 401 | 4 | Circumstantial |
| 6 | 71 | 19 | Indirect |
| 7 | 157 | 15 | Indirect |
| 8 | 303 | 13 | Circumstantial |
| 9 | 86 | 19 | Partially indirect and partially direct |
| 10 | 221 | 19 | Indirect |
| Total | 5089 | 172 (165 minus duplicates) |
*Indirect: data directly support the proposition. Circumstantial: no data directly or indirectly support the proposition, but there are circumstantial data which are useful to the proposition. Partially direct: part of the proposition is directly supported by data.