Variation in Laboratory Reporting of Haemolysis - a Need for Harmonisation.

Aim: The purpose of this survey was to determine the cut-offs being used by Australian laboratories using their instrument's Haemolysis Index (HI), whether these cut-offs vary, and at what level of haemolysis (or haemolysis index) did laboratories stop reporting one or more analytes. This was done in response to the large numbers of haemolysed samples reported in the RCPAQAP Key Incident Monitoring and Management System External Quality Assurance program (KIMMS EQA) and lack of information in the literature at the time regarding what to do once a haemolysed sample was identified. As it was known from discussions with laboratory personnel that different instruments reported their HI differently, we asked for the results to be provided in g/L free haemoglobin.

Method: An electronic survey was conducted with participants enrolled in the RCPA Quality Assurance Programs with a total of 68 laboratories responding to this survey. Some questions attracted a lower level of response.

Results: The responses showed a poor understanding of the relationship between HI units and haemoglobin concentration. There was wide variation in the way HI results were reported and thus comparing cut-off values for reporting specific analytes based on the HI was impossible to determine.

Conclusion: There is a need to harmonise the way laboratories report analytes in the presence of haemolysis. This would involve adopting a uniform definition of HI and a protocol for laboratories to confirm for themselves the level of HI at which each analyte is no longer reported, as this is method dependent and so will vary from laboratory to laboratory.