| Ethical approval needed | No ethical approval needed | Informed consent needed from every patient | No informed consent needed from every patient |
| Albania | Austria | Albania | Austria |
| Belgium# | Czech Republic | Belgium# | Croatia |
| Bulgaria | Denmark | Bulgaria | Czech Republic |
| Croatia | England | Germany | Denmark |
| Estonia | Ireland | Greece | England |
| Germany | Netherlands | Lithuania | Estonia |
| Greece | Slovenia | Norway | Ireland |
| Latvia | Scotland | Portugal | Latvia |
| Lithuania | Wales | Serbia | Luxembourg |
| Luxembourg | Spain | Netherlands | |
| Norway | Switzerland | Poland | |
| Poland | Turkey | Slovakia | |
| Portugal | Ukraine | Slovenia | |
| Serbia | Scotland | ||
| Slovakia | Wales | ||
| Spain | |||
| Switzerland | |||
| Turkey | |||
| Ukraine |
#: unable to participate as processing time of ethical approval was too long, except for one respondent.