Number of returned and completed questionnaires across all countries
| Country | Returned | Completed | %# |
| Brazil | 33 | 27 | 5.7 |
| Canada | 98 | 81 | 17.1 |
| France | 99 | 99 | 20.9 |
| Italy | 62 | 62 | 13.1 |
| Spain | 75 | 74 | 15.6 |
| The Netherlands | 72 | 72 | 15.2 |
| USA | 64 | 59 | 12.4 |
| Total | 503 | 474 | 100 |
#: percentage of total completed questionnaires
Return rate is significantly different between the countries (p<0.001)