Dear Suchaya Boonvivirya,
Thank you for the interest in our study. In fact, the main circumstance that made our study possible was the national registration of nurses, that we have in the Netherlands. If a nurse has passed her/his exams this is nationally registered. For once, we received permission to mail this entire group with an invitation letter including a password for the online questionnaire. Do you have some registration of nurses, maybe on a more local or regional level, in Thailand?
best wishes,
Matti Rookus