Patient safety is one of the important dimensions of quality, being extremely important for all healthcare activities, including the work of medical laboratories. 70-80% of medical diagnoses and medical conduct are based on tests performed by medical laboratory specialists [2]. External quality control as a medical service is a tool that measures the efficacy and comparability of measurement methods used by medical laboratories [4].
The role of external quality control for medical laboratories is to:
- contribute to providing reliable and comparable results to patients so that a patient is not healthy on the basis of an analytical report issued by a laboratory and ill on the basis of another analysis bulletin (issued by another laboratory or even by same laboratory at close times),
- save money in the public and private system by providing results of medical analyzes of patients leading to the most accurate and complex medical diagnosis [4]. | 
