Population
Non-regular blood donors (n= 692).
Intervention
Web-based videos sent via WeChat, and guided by an extended theory of planned behavior (Intervention group), (n= 285).
Comparison
Regular, short text reminder SMS messages (Control group), (n= 407).
Outcome
The Intervention group re-donation rate was significantly higher (16.14%), than the Control group rate (5.16%). Men aged 31 to 45, who had donated blood twice had a higher re-donation rate after the web-based video intervention than after the text messages. After the web-based intervention, repeat donors' improved blood anxiety, outcome expectations, and cognition of the blood donation environment were significantly higher than those of the non-repeat donors.