Exact time of venous blood sample collection - an unresolved issue, on behalf of the European Federation for Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Preanalytical Phase (WG-PRE).

Objectives An accurate knowledge of blood collection times is crucial for verifying the stability of laboratory analytes. We therefore aimed to (i) assess if and how this information is collected throughout Europe and (ii) provide a list of potentially available solutions. Methods A survey was issued by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group on Preanalytical Phase (WG-PRE) in 2017, aiming to collect data on preanalytical process management, including sampling time documentation, in European laboratories. A preceding pilot survey was disseminated in Austria in 2016. Additionally, preanalytical experts were surveyed on their local setting on this topic. Finally, the current scientific literature was reviewed on established possibilities of sampling time collection. Results A total number of 85 responses was collected from the pilot survey, whilst 1347 responses from 37 European countries were obtained from the final survey. A minority (i.e. ~13%) of responders to the latter declared they are unaware of the exact sampling time. The corresponding rate in Austria was ~70% in the pilot and ~30% in the final survey, respectively. Answers from 17 preanalytical experts from 16 countries revealed that sampling time collection seems to be better documented for out- than for in-patients. Eight different solutions for sample time documentation are presented. Conclusions The sample collection time seems to be documented very heterogeneously across Europe, or not at all. Here we provide some solutions to this issue and believe that laboratories should urgently aim to implement one of these.