Keynote Message

Whether or not we trust our endocrine results is really a matter of whether they are fit for purpose. That is, whether or not clinical management decisions based on those results are appropriate or inappropriate. Clinical management decisions include confirming diagnoses, ruling out diagnoses, and making dose adjustments in long-term therapy.

There are factors which will affect the analytical accuracy of an endocrine result including method choice and analytical interferences and there are those which will affect the interpretation of endocrine results including physiological and pre-analytical ones.

The effect of method choice on results can be assessed by appropriate validation and quality control and by periodic checks of internal consistency and precision. External quality assessment (EQA) also helps determine how local results may differ from international results. Since 2012, the European Society of Veterinary Endocrinology (ESVE) has run an international EQA program sending out aliquots of a single sample to more than 50 labs twice a year. So far the scheme has resulted in the correction of reporting units and discontinuation of some methods. Furthermore, it has identified an unexpected spread in cortisol and fructosamine results, demonstrated that some insulin methods cannot detect low concentrations, and confirmed difficulty in reaching consensus on oestradiol. In analytes where consensus was unexpectedly poor (e.g., cortisol and fructosamine), there was no relationship between the reference limits reported by the labs and the results obtained, that is, not only does there need to be caution in interpreting common endocrine results against textbook reference intervals and decision thresholds, but also in some cases when comparing them to local lab reference limits. By providing this EQA scheme, the ESVE aims to improve the international consistency of endocrine laboratory results and accuracy of endocrine diagnoses.

Key References

1.  ESVE EQA Reports and Participant Lists: http://www.esve-payments.org/esve/eve-qas