The amount of time a candidate is on the Wait List. Waiting times can be influenced by many factors, including:

• blood type (some are rarer than others)
• tissue type
• height and weight of transplant candidate
• size of donated organ
• medical urgency
• time on the waiting list
• the distance between the donor's hospital and the potential donor organ
• how many donors there are in the local area over a period of time and
• the transplant center's criteria for accepting organ offers

Depending on the kind of organ needed, some factors are more important than others.