Population-based colorectal cancer screening programmes using a faecal immunochemical test: should faecal haemoglobin cut-offs differ by age and sex? oleh Eunate Arana-Arri, Isabel Idigoras, Begoña Uranga, Raquel Pérez, Ana Irurzun, Iñaki Gutiérrez-Ibarluzea, Callum G. Fraser, Isabel Portillo, EUSKOLON Group