Setting inventory levels for hospital blood banks.

A method is devised to predict the hospital blood bank inventory of each of the eight blood types that will be adequate on all but a given fraction of days (shortage rate). Analysis of the model confirms and extends prior statistical models and provides a rationale for a number of observations made on some common blood inventory practices. Comparison of the relationship between inventory levels and shortage rates predicted by the model and that calculated from data from 21 hospital blood banks of varying sizes, located in four separate parts of the country, reveals agreement within approximately 10 per cent. A procedure is presented and allows blood banks to select inventory levels and shortage rates based on their mean demand for blood.