Selected characteristics of reviewed publications
| Identified studies | ||
| # | % | |
| Year published | ||
| Before 2010 | 1 | 0.5% |
| 2010 | 6 | 2.9% |
| 2011 | 18 | 8.7% |
| 2012 | 17 | 8.2% |
| 2013 | 20 | 9.7% |
| 2014 | 30 | 14.5% |
| 2015 | 38 | 18.4% |
| 2016 | 57 | 27.5% |
| 2017* | 20 | 9.7% |
| Region | ||
| Africa | 45 | 21.7% |
| USA | 50 | 24.2% |
| South-East Asia | 19 | 9.2% |
| Europe | 2 | 1.0% |
| Eastern Mediterranean | 26 | 12.6% |
| Western Pacific | 9 | 4.3% |
| Multiple | 38 | 18.4% |
| NA | 18 | 8.7% |
| Article type | ||
| Systematic review | 36 | 17.4% |
| Non-systematic review | 17 | 8.2% |
| Primary research (all) | 127 | 61.4% |
| Primary research - quantitative | 85 | 41.1% |
| Primary research - qualitative | 19 | 9.2% |
| Primary research - mixed methods | 23 | 11.1% |
| Conceptual literature | 27 | 13.0% |
*the search concluded on 31 May, 2017.
NA, not available.