Effect of Different Types of Messages on Readiness to Indicate Willingness to Register for Organ Donation During Driver's License Renewal in Japan.

Background. In Japan, a recent opinion poll in 2017 showed that 41.9% of the respondents wished to donate their organs, but only 12.7% declared their intention to donate or not do so. Therefore, it is important to explore measures to prompt more individuals to register their intention about organ donation. Methods. A field experimental questionnaire survey was conducted to confirm the effect of a prompt message for registering intentions for organ donation, which was communicated at a driver's license center. The study employed a prospective randomized control design. Seven thousand six hundred fifteen individuals visited the Tokyo Fuchu License Examination Center to update their driver's license and received leaflets including a message prompting organ donation registration and the questionnaire. Of the participants who received leaflets, 3224 respondents provided complete responses to the questionnaire (valid response rate: 42.3%). Subsequently, a questionnaire survey was conducted to assess the participants' willingness to register for organ donation. A control condition and the following types of messages were used: peer-framed, gain-framed, loss-framed, reciprocity-framed, and peer + reciprocity-framed. Results. The reciprocity message emerged as a significant predictor of increase in immediate decision response. The loss-framed message was a significant predictor of decrease in no intention to register. Conclusions. This study found that reciprocity and loss-framed messages promoted the readiness to register for organ donation among individuals from a Japanese urban area. Mandatory distribution of prompt messages at every driver's license centers in Japan would be recommended.