How to improve the performances of fecal immunological tests (FIT): need for standardization of the sampling and pre-analytical phases and revision of the procedures for comparison of methods

Lack of reference materials and standard procedures, on faecal tests leads to major problems in harmonisation of methods and do not allow the comparison of outcome data. In particular the absence of standardisation of pre-analytical characteristic was noted for faecal test methods for haemoglobin since different manufacturers have developed different sampling procedures and report units. Moreover the physical characteristics of the faecal specimen and the designs of specimen collection devices do not allow analysis of samples on different systems in consequence, faecal tests cannot be compared using standard evaluation protocols. To improve the harmonization of results generated using different analytical systems and the overall performances of test on faecal materials we propose the introduction of standard procedures for sampling and pre-analytical phase and the adoption of specific procedures based on the use of artificial biological samples for comparison of methods. Harmonization of sampling devices with the use of a standard design for pickers and a standard ratio between analyte and buffer for different manufacturers represent a mandatory step in the roadmap for harmonization of clinical laboratory measurement on faecal materials and can allow a significant standardisation of results generated by different devices. The creation of specific protocols for the evaluation and comparison of analytical methods for analyse of faeces could lead to a significant improvement in the performance of methods and systems.