Predicting future blood supply and demand in Japan with a Markov model: application to the sex- and age-specific probability of blood donation.

Background: Simulation studies were performed to predict the future supply and demand for blood donations, and future shortfalls.

Study Design And Methods: Using data from all donations in 2006 to 2009, the Markov model was applied to estimate future blood donations until 2050. Based on data concerning the actual use of blood products, the number of blood products needed was estimated based on future population projections.

Results: We estimated that the number of blood donations increased from 5,020,000 in 2008 to 5,260,000 in 2012, but will decrease to 4,770,000 units by 2025. In particular, the number of donors in their 20s and 30s decreased every year. Moreover, the number of donations required to supply blood products would have been increased from 5,390,000 in 2012 to 5,660,000 units in 2025. Thus, the estimated shortfall of blood donations is expected to increase each year from 140,000 in 2012 to 890,000 in 2025 and then more than double to 1,670,000 in 2050.

Conclusion: If the current blood donation behaviors continue, a shortfall of blood availability is likely to occur in Japan. Insufficient blood donations are mainly related to a projected reduction in population of 20 to 30 year olds, a significant group of donors. Thus, it is crucial to recruit and retain new donors and to develop recommendations for proper use of blood products to minimize unnecessary use. This study provides useful information that can be used by governments to help ensure the adequacy of the blood supply through promoting donations and conserving blood resources.