Evaluation of the clinical use of blood products is often done by monitoring or surveying clinical practice against objective indicators of performance. This is perhaps better described as benchmarking than audit. Useful indicators of practice (quality or performance indicators) must be easy to collect and quantifiable.

Quality indicators may be used to monitor and evaluate the quality of the therapeutic transfusion process or compliance with clinical guidelines. There are two types of indicators: internal and external.

Internal indicators are used for quality management and improvement of the clinical transfusion process within an institution. They must be relevant for the critical steps in the process and the professionals involved. They must be specific and detailed, easy to sample, educative and effective in stimulating actions for improvement.

External indicators provide information for external control agencies such as health care inspectorate and/or for comparison between hospitals (benchmarking). These have to provide monitoring or signaling information about the quality of the process, measure global aspects such as global outcome and require good validation. According to what they measure three types of indicators can be described:

Structure indicators: How well have I organised the process?
Process indicators: Am I doing well?
Outcome indicators: Do I reach the result required?

Indicators are only one tool for evaluating practice. In some cases audit may provide better information. However, if used in the right way indicators may be an efficient and tool for improving the quality of the therapeutic transfusion process.