Summary provided by Dr. Baia Lasky
Platelet demand continues to increase (1) and U.S. hospitals face frequent shortages (2). Between 2010 and 2019, the American Red Cross’ (ARC) platelet distributions increased by 16.6% (778,775 to 907,851 units); therefore, a reliable and sustainable apheresis platelet donor (APD) base is essential to support patient care.
The modal age of APDs is increasing, raising questions about the resiliency of the platelet supply as the apheresis donor base “ages out” without adequate replenishment with younger donors (3). Analysis of ARC APDs from 2010 through 2019 challenges this perspective, demonstrating robust growth of young APD cohorts (4) . During the study period, the ARC APD pool increased from 87,573 to 115,372 donors representing an overall growth of 31.7%.
Relative Representation of Apheresis Platelet Donors
Similar to previously published data (3), our study demonstrated an upward shift of the modal APD age from the 51-55 year group (16.1%, Figure 1A, peak A1) in 2010 to the 56-60 year group (12.6%, Figure 1A, peak A2) in 2019. However, while the peak has shifted to an older age group, the relative representation of older aged donors showed a declining trend over time. This has been complemented by an increase in relative representation of donors aged 16-40 years, with the largest increases in the 26-30 year and 31-35 year age groups. Relative representation particularly declined in the middle-aged groups 41-60 years. Thus, a closer examination of APD demographics beyond the overall shift in the modal age of donors revealed a more complex story.
Absolute Representation of Apheresis Platelet Donors
To better understand growth trends, the absolute number of donors within each age group in 2019 was compared with the same age group in 2010 (Figure 1B). Notably, younger donors (16-40 years) as well as older donors (>55 years) both demonstrated substantial growth. The largest percent increases were seen in the 66-70 year (108.1%), older than 71 years (119.3%) and 26-30 year (99.9%) groups. However, substantial increases were also seen in the younger groups of 16-18 years (98.4%), 31-35 years (94.1%), and 23-25 years (87.1%). While the changes within any age group were not statistically significant from year to year, the cumulative changes for each age group, when comparing 2019 to 2010, were statistically significant (p<0.05).
First-Time Apheresis Platelet Donors
All age groups experienced growth of first-time donors (FTD) each year of the study period with a total of 15,883 new donors added to the APD base from 2010 to 2019 (Figure 2). Donors 19-35 years represented the largest numbers of FTD overall. Of all FTD presenting over the last decade, the youngest age groups (16-40 years) comprised 61.3%, the mid-range age group (41-55 years) 21.7%, and the oldest age groups (56-71+ years) 17.0%.
Total Contributions
The youngest APD groups (16-40 years) demonstrated the greatest number of FTD both in 2019 and over the last decade and donated at a high split rate (ie, produced a high number of platelet products per collection) but had the lowest donation frequency. The mid-range donors (41-55 years) had the highest split rate, intermediate donation frequency and a decline in absolute numbers. The oldest donors (56-71+ years) demonstrated the highest donation frequency and continued growth in total absolute representation but the lowest split rate. The net effect of these combined attributes was that the oldest age groups contributed the largest proportions of apheresis platelet units. Furthermore, this proportion was growing. Growth in the oldest age groups may not necessarily be a point of concern but a strategic choice because these donors were likely motivated, available, easier to retain, and less likely to be deferred and had adverse event rates similar to those of donors between 21 and 50 years. Growth in the oldest age group of APDs, as donors “age up” into the most productive cohort, has the potential to sustain platelet collections before they “age out.”
Discussion
While our study confirmed that the modal age of APDs has increased, this masks growth in the younger donor base (16-40 y), despite the absence of focused youth engagement, countering the claim that modern youth are disinterested in volunteerism relative to older generations. Yet, we continue to have platelet shortages and there remains concern in our industry as to whether blood collectors can recruit sufficient donors to consistently meet platelet demand. One solution advocated by some has been to introduce paid platelet donors to bring in overall larger numbers of donors and to perhaps skew them towards a younger cohort. The paid donor base, however, is driven by unique motivations vulnerable to disruptors such as the COVID-19 pandemic (5).
As an industry, we need to continue to study APD motivations. Understanding donation patterns and behaviors of each donor age segment may help to ensure that older donors’ high split rate and high donation frequency are balanced against the need to continue introducing new, young donors into the donor base. Additionally, other solutions that can support the platelet supply should be explored such as centralized real-time availability and utilization data (6), supply chain redundancies (7), whole-blood-derived platelets, and technological innovations.
FIGURE 1A: Relative age distribution among all apheresis platelet donors from 2010 through 2019
FIGURE 1B: Percent change of total number of apheresis platelet donors in each age group from 2010 to 2019
FIGURE 2: Total number of first-time donors within each age group from 2010 through 2019
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