Methodology and outcomes of platelet aggregation testing in Australia, New Zealand and the Asia-Pacific region: results of a survey from the Royal College of Pathologists of Australasia Haematology Quality Assurance Program.

Platelet aggregometry is widely used to investigate platelet function but its performance is poorly standardized between laboratories. The aim of this work was to document the platelet aggregation methods used in specialist laboratories enrolled in the Haematology Quality Assurance Program of the Royal College of Pathologists of Australasia. A questionnaire requesting many details of methodology was distributed and from the responses, we determined a consensus view. Consensus was defined here as >70% agreement among respondents in answer to a question and this was seen for a number of aspects of the preanalytical, analytical and interpretive phases. However, for many questions there was a wide variation in responses. Sixteen laboratories provided a breakdown of the types of abnormal results typically seen in a 12-month period. In these laboratories a total of 1400 patients were tested and 390 (27%) had abnormal platelet function. Although it was common to diagnose the cause as aspirin or an aspirin-like defect or a release/storage pool disorder, the range of experience was wide and other rare defects were reported. We conclude that whilst there are a number of points of agreement between laboratories in platelet function testing, standardization could be improved.