Results {1-3}

EU Guideline 2010 {2}

According the EU Guideline 2010, "iFOBT have improved test characteristics than gFOBT, and they are currently the test of choice for population CRC screening. In different settings, individual device characteristics like ease of use by participant and laboratory, suitability for transport, sampling reproducibility and sample stability are important and should be all taken into account when selecting the iFOBT most appropriate for CRC screening programme (Level of evidence II, Grade of recommendation A).

Adoption of test device and the selection of a cut-off concentration should follow a local pilot study to ensure that chosen test, test algorithm and transport arrangements work together to provide a positivity rate that is clinically, logistically and financially acceptable (Level of evidence VI, Grade of recommendation A).

Maximum period between collection and analysis is significantly shorter  than for gFOBT (14-21 days), and screening programmes should adopt the conditions and period of storage described in manufacturer’s Instructions for use and should be appropriate for local conditions which might expose samples to high temperatures for long period of time (Level of evidence III, Grade of recommendation A).

Despite the fact that dietary constituents present potential interference in gFOBT, dietary restriction has not been demonstrated to significantly increase screening specificity and risks reducing participation rate.  The potential for dietary interference is significantly less for iFOBT. With the qualification that a diet peculiar to a particular country or culture may not have been tested or reported, dietary restriction is not indicated for programmes using either gFOBT or iFOBT (Level of evidence II, Strength of recommendation D).

Some drugs which could cause GI bleeding like aspirin, NSAIDs and anticoagulants present potential interference in gFOBT and iFOBT, drug restriction is not recommended for population screening programmes using either gFOBT or iFOBT (Level of evidence III, Strength of recommendation  D).

Since many factors influence the uptake and reliability of sample collection, a local pilot study should be undertaken to ensure that the chosen device and associated distribution, sampling and labelling procedures are acceptable (Level of evidence VI, Grade of recommendation A).

The number of laboratory sites (analytical centres) should be minimised with automated analytical systems utilised whenever possible and agreed common testing procedures adopted by each centre, since the analysis need to be reproducible across screening population. The samples should be analysed without delay to avoid further sample denaturation and avoid an increase in false negative results. Inter-laboratory analytical imprecision can be observed through established external quality assurance schemes. Common analytical platforms, analytical and quality standards and shared staff training will improve consistency. (Level of evidence VI, Grade of recommendation B).

All laboratories providing population screening should be led by a qualified clinical chemist trained and experienced in the techniques used for analysis and with clinical quality assurance procedures (Level of evidence VI, Grade of recommendation B).

All laboratories providing screening service should be associated with a laboratory accredited to ISO 15189:2007 Medical laboratories-Particular requirements for quality and competence. Also they should perform Internal Quality Control procedures and participate in appropriate External Quality Assessment Scheme (Level of evidence VI, Grade of recommendation B).

Distribution of FOBT kits by mail, using local postal service is an effective way of reaching the designated population (Level of evidence II, Grade of recommendation B).

Automated check protocols should be implemented to ensure correct identification of the screen population and complete and accurate recording of individual screening participation and test results.  Protocols should be implemented to ensure standardised and reliable classification of the test results (Level of evidence VI, Grade of recommendation A).

Quality assurance of iFOBT

Manufacturer’s Instructions for Use must be followed. Daily checks of analytical accuracy and precision across the measurement range with particular emphasis at the selected cut-off limit should be performed. Sufficient instrumentation should be available to avoid delays in analysis due to instrument failure or maintenance procedures. Performance data (both internal quality control and external quality assessment data) should be shared and reviewed by a Quality Assurance team working across the programme. (Level of evidence VI, Grade of recommendation B).

All laboratory performance outcomes like uptake, undelivered mail, time from collection to analysis, analytical performance, positivity rates, lots and spoilt kits and technical failure rate, technical performance variability and bias should be each subject to rigorous monitoring (Level of evidence VI, Grade of recommendation A).

The proportion of unacceptable tests received for measurement is influenced by the ease of use of the test kit and the quality of the instructions for use. This proportion should not exceed 3% of all kits received; less than 1% is desirable (Level of evidence III, Grade of recommendation A)."

Box 1. Some published Guidelines on adenomas/CRC screening and diagnosis

In the majority of jurisdictions in the EUnetHTA survey in 2013, local and/or regional guidelines or recommendations on CRC screening were reported (Box 2).

Box 2. EUnetHTA survey (2013) about adenomas/CRC screening/diagnosis in different MSs

Austria               No national guideline. A voluntary quality assurance program for screening colonoscopy is in place (partners: Main Association of Social Security Institution and Austrian Society for Gastroenterology and Hepatology OeGGH).                Russia Russian Gastroenterology Association Guidelines.                Luxembourg  European guidelines for quality assurance in colorectal cancer screening and diagnosis.                Lithuania         National guidelines.                Italy (Lazio and Veneto Region)      National and regional recommendations on the basis of European guidelines.   Scotland           Guidance is provided by the UK National Screening Committee.               Spain  Grupo de trabajo de la guía de práctica clínica de prevención del cáncer colorrectal. Actualización 2009. Guía de práctica clínica. Barcelona: Asociación Española de Gastroenterología, Sociedad Española de Medicina de Familia y Comunitaria, y Centro Cochrane Iberoamericano; 2009. Programa de Elaboración de Guías de Práctica Clínica en Enfermedades Digestivas, desde la Atención Primaria a la Especializada: 4               France               Guidance for good practice by HAS (updated in June 2013). The document contains epidemiological data, general description of the screening programmes, algorithms for different groups at risk.   Croatia              National Programme for CRC Screening.              Slovenia 2003 guidelines (currently being updated).