Table 1.
Overview of the studies included in this systematic review.
| Study characteristics | N |
|---|---|
| 142 | |
| Study design | |
| - Randomised controlled trial, including secondary analyses of data collected as part of a randomised controlled trial | 7 |
| - Prospective non-randomised study | 85 |
| - Retrospective study | 28 |
| - Mixed prospective and retrospective | 1 |
| - Cross-sectional study | 1 |
| - Case series | 2 |
| - Not specified | 18 |
| Location of study authors | |
| - North America | 33 |
| - Europe* | 72 |
| - Asia | 14 |
| - UK | 5 |
| - More than one continent | 15 |
| - Australia | 1 |
| - Middle East | 2 |
| Decade study published | |
| - 2020 onwards | 38 |
| - 2010-2019 | 66 |
| - 2000-2009 | 30 |
| - 1990-1999 | 8 |
*Turkey classified as Europe.