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Distribution of countries of the studies (N=20).
| Country | Studies, n (%) |
| United States | 4 (20) |
| United Kingdom | 2 (10) |
| Spain | 2 (10) |
| Saudi Arabia | 2 (10) |
| South Korea | 1 (5) |
| Turkey | 1 (5) |
| Czech Republic | 1 (5) |
| Italy | 1 (5) |
| Denmark | 1 (5) |
| Canada | 1 (5) |
| Austria | 1 (5) |
| Ireland | 1 (5) |
| China | 1 (5) |
| Germany | 1 (5) |
