The relative efficacy of telephone and email reminders to elicit blood donation

The aim of the study was to test the relative efficacy of telephone and email reminders to trigger blood donation. A sample of 3454 donors was randomized to one of three conditions: phone only (n = 1176), email only (n = 1091) and phone + email (n = 1187). There was a higher proportion of donors who registered to give blood in the phone + email condition (18·45%) compared to the other two conditions (phone: 15·73%, P < 0·05; email: 13·20%; P < 0·001); this effect was apparent only in men. The phone and email conditions did not differ significantly (P = 0·16), suggesting equivalent efficacy.