To be eligible to donate blood, potential donors must meet certain eligibility criteria to ensure safety to the donor and to the blood supply. In Australia, there is no reliable estimate of the size of the donor-eligible population. This study uses a refinement to a published method to determine the population prevalence of donor-exclusion factors and subsequently estimates the size of the potential donor pool in Australia.

A total of 70 donor-exclusion factors (in addition to age) were identified. The donor-eligible population was estimated by subtracting the prevalence of the exclusion factors from the total population. Prevalence of the donor-exclusion factors was adjusted for age, deferral period, and overlap of multiple conditions. Overlap was adjusted by extending a published random-probability model according to known association of epidemiologic data on overlapping conditions.

The most prevalent (deferral period-adjusted) donor-exclusion factor among the 16- to 80-year-old Australian population was variant Creutzfeldt-Jakob disease-related travel risk (6.8%) followed by upper respiratory tract infections (6.4%). After exclusion of all factors, and accounting for overlapping factors, 62% of 16- to 80-year-olds or 47.3% of the total population were donor eligible in Australia.

We developed a refined method for estimating the size of the donor-eligible population. Applying this method to Australia, we estimate that approximately 10.7 million people (62% of the 16- to 80-year-olds) were eligible to donate blood in Australia in 2012.