Those who did not respond received one follow-up invitation.
Training programs that did not respond received additional mailings and telephone calls to improve the response rate.
General practitioners who did not respond received a reminder.
Patients who did not respond received a second invitation 2 3 weeks later.
Those patients who responded received an average of 33 units of RBCs during their hospital stay.
Patients who did not respond received a reminder by telephone or postal mail.
Those (n = 2,341, 36% of the selection) who did not respond received a reminder after four weeks.
Two weeks after this, any recipient who had not responded received a "last chance to participate" email.
Patients received a consent form and the study questionnaire by postal mail and those who did not respond received a reminder by telephone or postal mail.
Orthopaedic surgeons who did not respond received two reminders, one after one and a half weeks and if still no response again after 3 weeks.
