Results of database search
| Data source | Results | Duplicate removed | Unrelated articles removed | Reviewed abstracts and titles |
| CINAHL (EBSCO) | 237 | 185 | 113 | 68 |
| Pubmed/Medline | 236 | 236 | 76 | 58 |
| Web of Science | 268 | 247 | 86 | 63 |
| Nursing and Allied Health | 12 | 12 | 4 | 4 |
| Scopus | 314 | 275 | 47 | 47 |
| EMBASE(OVID) | 229 | 168 | 59 | 59 |
| Academic Search Complete (EBSCO) | 744 | 698 | 228 | 122 |
| Maternity & Infant Care (OVID) | 87 | 76 | 37 | 37 |
| Hand searched | 23 | NA | 2 | |
| Total | 2477 (+23 hand search) | 2126 | 779 | 461 |
NA, not available.