Medical Sociology of Community Blood Donor Recruitment Networks and Transfusion-Supply Reliability in Kenyan Counties: A Social-Network Estimation of Donor Brokerage and Shortage Exposure

Community blood donor recruitment in Kenyan counties is organised through networks of brokers, teachers, clergy and workplace convenors whose ties determine which donors reach which collection sites. Medical sociology has theorised these networks as a mechanism linking social organisation to transfusion-supply reliability, but the field lacks an assessment of whether the designs used to evaluate recruitment interventions can detect the effects the theory predicts. No observational data were used or claimed. Under a declared variance structure with between-cluster SD = 6.0, residual SD = 4.5 and intraclass correlation = 0.64, power was estimated across 2000 design cells spanning 8, 16, 24 and 32 clusters and effects of 3, 5 and 8 percentage points. The analysis indicates that 56 clusters are required to detect a 5-percentage-point effect at 80% power, a figure that exceeds the cluster counts typically available to county transfusion programmes. The evidentiary problem in this field is not a shortage of theory but a mismatch between the clustered structure of donor networks and the designs used to test network interventions, and it specifies the design conditions under which brokerage effects become estimable.