A stable blood supply count is vital for modern healthcare, which means retaining first-time donors (FTD) is a challenge requiring continuous engagement. Thus, implementing effective strategies is essential. Previous studies explored interventions such as email reminders, personalized letters, and follow-up calls, but a comprehensive synthesis is lacking. By consolidating the existing evidence, our study aims to fill the gap in knowledge and guide policy-makers, healthcare professionals, and blood donation organizations in implementing evidence-based strategies for this ending.

The databases PubMed, Scopus, Embase, Web of Science and Cochrane were searched for abstracts published until August 2023. The search yielded 851 results which were screened for randomized clinical trials relevant to the theme. Two independent, blind reviewers participated in each step of the article selection with a third reviewer to solve any conflicts, in accordance with PRISMA guidelines.

In this study, 43 papers were assessed, with 4 selected for inclusion. The papers examined 16 different interventions with varying degrees of significance in promoting follow-up blood donation within 5 to 22 months. Statistics were focused on two specific interventions, due to the variability between studies interventions: messages with emotional content, showing a favorable pooled Hazard Ratio of 1.28 (95% CI, 1.09 - 1.50) in three randomized trials involving 4932 intervention participants and 5002 controls; and incentives (keychain, t-shirt, and card sleeve), yielding a pooled Hazard Ratio of 1.05 (95% CI, 0.93 - 1.18) in three randomized trials with 3860 intervention participants and 3932 controls. While the latter intervention did not reach statistical significance, both exhibited reasonable heterogeneity (I2 = 44% & I2 = 32%, respectively).

This meta-analysis supports the implementation of interventions which appeal to the emotional aspects of blood donation with a statistically significant improval in follow-up return to donation. No incentive reached statistical significance in their respective study as well as in pooled analysis, however. This seems to contribute to the trend in blood donation literature of altruism as a prime motivator to blood donation. In this sense, appealing reminders of the importance of the act may contribute to the renewed intention to participate in blood drives. Short duration of follow-up in these studies deters any further evaluation of whether this effect will exhibit a diminished return across the participants’ donor career.

Overall, this meta-analysis supports the use of emotional reminders as low-cost and effective interventions in promoting FTD return to donation and possible long-term career as repetition donors.