Abstract:
Background: Blood is the most precious and unique gift that one human being can give to
another. It is lifesaving fluid that cannot be created artificially, but is only collected from donors
which are the precious resources.
Objectives: The study aimed to model time to return of volunteer blood donors’ in National
blood bank, Addis Ababa, Ethiopian.
Methods: A retrospective cohort study had been conducted at National Blood Bank, Addis
Ababa, Ethiopia. In this study, a total of 6,019 voluntary blood donors were included and
baseline data had been obtained from existing databases of all volunteer blood donors who
donated blood from September 06, 2012 to September 11, 2013 and whether he/she returned
or not were followed until September 2015. In this study Exponential, Weibull, log-logistic
and lognormal as baseline hazard functions with the gamma and the inverse Gaussian frailty
distributions were used.
Results: A total of 6,019 voluntary blood donors donated blood during a period of 06 Sept
2012 to 11 Sept 2013. The median returning time of the donors was 26 months. About 46.7%
of the donors were returned to donate blood again during the study period. The clustering effect
is significant on modeling time to return of volunteer blood donors. According to the output
of the Lognormal Gamma frailty model, gender of the donors’, age of the donors’, weight,
occupation, donation experience, and experiencing donors’ reaction were the significant risk
factors at 5% level of significance.
Conclusion and Recommendation: Lognormal-Gamma frailty model is the model that best
described time to return of the donors’ dataset. Being male donor, donation experience (repeat
donor) and increasing weight (in Kg) significantly shorten/minimize the time-to-return of blood
donors, while being in the age group (45-65), being a student and experiencing donors’ reaction
prolongs the time to- return of volunteer blood donors. For those groups whose return time were
prolonged, policy makers and human resource managers are expected to make interventions,
and design appropriate policy, programs and donor motivational strategies to improve their
return time.
