Predicting a donor's likelihood of donating within a preselected time interval

Abstract

The procurement of some advanced blood components, like quarantined plasma units, depends critically on retesting the donor within a fixed time frame. For health care systems, such as that in Germany, with mandatory retesting of donors before plasma release, the reliable identification of donors who are more likely to return in time has an immense practical implication, because their blood components could be preferably selected for quarantine purposes. The donation histories of about 760 000 donors with 4910 000 donation attempts were analysed. We developed a logistic regression model to calculate a probability of donation, p(Dts-te), within a preselected time frame (ts-te). The donation history was compounded in a score and shown to be very useful for determining p(Dts-te). A logistic regression model was developed with score and donor status as parameters; different regression coefficients applied to first-time-donors (ftd) and to repeat donors (intercept, int, and score factor, scf ). This model allowed us to determine the probability of donation, p(Dts-te), within a preselected time interval, e.g. 6-9 months after an index donation. The p(Dts-te) can be calculated for any donor of blood services. The p(D170-275 days) ranged from about 22% to 86% for any index donation in 1996/97. First-time donors had a p(D170-275 days) of 33% and were more likely to return within the time interval than certain subsets of repeat donors who can be defined by our model. We provided a technical procedure to increase the rate of plasma unit release after quarantine storage and showed the usefulness of our procedure for blood component management, if quarantine storage is required. By applying the model to our current plasma quarantine programme we could retrieve about 30% more units, which would represent about 30 000 units per year, without incurring additional costs. General implications for blood collection, like planning blood drives, were discussed. The whole demand of a health care system for single plasma units may be met by quarantine plasma and their cost-efficiency can be improved.

Predicting blood donor arrival

“…This is consistent with the data of James and Matthews 5 who found that the proportion of returning donors increased with the donors’ number of previous donation attempts. It is also consistent with the prediction model of Flegel and colleagues, 6 which used a score function based on the donor's response to previous opportunities to donate as the main explanatory variable. A high number of donations during the preceding 2 years would be expected to result in a higher value of this score function.…”

“…Eighteen explanatory variables were selected. The choice of variables was based on previous reports on blood donor return behavior, 4‐8 as well as on the accessibility of the data and our assumptions about their potential predictive value. The explanatory variables are listed in Table 1, with summary statistics.…”

“…We are not aware of any previous studies that have focused on the prediction of donor arrival to scheduled appointments, however. Flegel and coworkers 6 have developed a logistic regression model for predicting a donor's likelihood of returning for a second donation within a given time interval, to decide whether the donor's plasma should be stored for quarantine purposes.…”

“…The aim of this study was to investigate if arrival of scheduled blood donors can be predicted with statistical models, and if so, which variables that are important for prediction. Previous studies on donor return behavior have shown that factors such as donor age, 4 previous donation pattern, 4‐6 and previous short‐time temporary deferrals 7,8 are useful in explaining the variation in donor return. These and other explanatory variables have been investigated and a logistic regression model for predicting the response to scheduled donation appointments is presented.…”

Public awareness of blood donation in Central Saudi Arabia

“…Male sex was also a significant predictor of frequent blood donation in the present study, together with the higher attitude score to donation. Experience of prior blood donation, number of previous donations, and duration from last donation are correlated with future behavior 40–42. Individual attachment with someone who donates blood, or knowing people who have received donated blood all could influence willingness to donate blood 30,43,44.…”