Table 1.

Comparison Between the ISTH,³ CLSI,⁴ and BCSH⁵ Guidelines for Preanalytical Variables in Platelet Function Tests.

ISTH	CLSI	BCSH
Blood samples for LTA should be collected after a short rest period for the participant, to attenuate the effect of exercise-induced adrenaline release on platelet aggregation.	–	Blood samples should only be collected from resting participants.
Blood samples for LTA should be collected from participants who refrain from smoking for at least 30 minutes, to attenuate the effect of exercise-induced adrenaline release on platelet aggregation.	–	Blood samples should only be collected from participants who have refrained from smoking on the day of testing.
Blood samples for LTA should be collected from participants who abstain from caffeine for at least 2 hours.	–	Blood samples should only be collected from participants who have refrained from caffeine ingestion on the day of testing.
It is uncertain whether blood samples for LTA should be collected from fasting participants. Although variations in glycemia and lipemia might slightly affect the results of LTA studies, it is uncertain whether these effects interfere significantly with the diagnosis of platelet function disorders.	If medically possible, patients should be fasting and should also avoid fatty meals prior to collection.	Blood samples should only be collected from fasting participants.

Abbreviations: BCSH, British Society for Hematology; CLSI, Clinical and Laboratory Standards Institute; ISTH, International Society on Thrombosis and Hemostasis; LTA, light transmission aggregometry.