Comparison of quantitative faecal immunochemical tests for haemoglobin (FIT) for asymptomatic population screening

Although colonoscopy, despite disadvantages, remains the “gold standard” for investigation of suspected colorectal disease, faecal immunochemical tests for haemoglobin (FIT) are now considered the best non-invasive investigation for use in asymptomatic population-based programmatic screening for colorectal neoplasia (1). FIT come in two formats, qualitative tests, based upon immunochromatography, and quantitative tests, based on immunoturbidimetry. Qualitative FIT have some advantages, including potential as point-of-care tests, but have major disadvantages (2), particularly that they have different analytical detection limits and thus give very different clinical outcomes (3). Quantitative FIT are much more suitable for larger-scale screening programmes and have many advantages (4), especially that estimates of faecal haemoglobin concertation (f-Hb) are obtained, allowing considerable flexibility in programme design.