Pre-analytical variability in laboratory studies. Monitoring and evaluation of pre-analytical error on the example of collected data at the West Pomeranian Cancer Center in Szczecin in Poland

Pre-analytical phase in laboratory studies may be influenced by multiple factors, which can be categorized into patient-related, patient-independent, and interfering factors. The first group includes diet, physical activity, body position, medicines, and stimulants. These are the most important factors because here the patient can consciously influence the laboratory results. Second group are the patient-independent factors such as gender, population, age, and pregnancy are beyond the control of the patient. The last category includes conditions such as hemolysis, lipemia, and hyperbilirubinemia. They can alter the results of coagulation tests and other biochemistry studies. Hence, clots in a specimen and the presence of hemolysis and the most common factors account for 80% of pre-analytical phase laboratory errors. It is absolutely necessary to implement procedures for monitoring and assessing pre-laboratory error as well as medical staff training regarding the collection, storage, and transport of samples.