| Version | Date of search | Records sent | |
| 1. The Cochrane Library | 2011, Issue 4 | 15 December 2011 | 9 |
| 2. MEDLINE (Ovid) | May Week 2 2009 to November week 3 2011 | 15 December 2011 | 43 |
| 3. EMBASE (Ovid) | 2009 Week 20 to 2011 week 49 | 15 December 2011 | 144 |
| 4. LILACS | May 2009 to December 2011 | 15 December 2011 | 10 |
| Totals | 206 |
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