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Introduction Since 2023, Welsh guidelines have recommended that the faecal immunochemical test (FIT) should be used in patients with symptoms suggestive of colorectal cancer (CRC). Those with a FIT result ≥10μgHb/g should be referred urgently for investigation for CRC. Our aim was to quantify the use of symptomatic FIT in Wales and to describe the performance characteristics of FIT at a cut-off of 10μgHb/g for colorectal cancer.Methods Using linked health records from the Secure Anonymised Information Linkage databank all adults registered in the Welsh Longitudinal General Practice Dataset with a recorded symptomatic FIT result from 2020 onwards were identified. Performance characteristics of FIT≥10μgHb/g for CRC by age group, sex and year of test were calculated including sensitivity, specificity, positive predictive value (PPV) and number needed to scope (NNS).Results 240,127 adults registered in WLGP underwent 289,829 symptomatic FITs in Wales from January 2020 to March 2025. The rate of testing rose over time from 4.91 (95%CI: 4.81-5.00) per 1000 person years in 2020 to 34.85 (95%CI: 34.60-35.11) in 2024. 2,864 CRCs were diagnosed in 166,863 patients with a year of available follow-up. 8.06% of patients with a FIT≥10μgHb/g were diagnosed with CRC compared to 0.21% with a FIT<10μgHb/g (p<0.0001). Over time PPV was reduced from 10.62% (95%CI: 9.37- 12.00) in 2020 to 6.40% (95%CI: 5.67-7.23) in 2024. This corresponded to an increasing proportion of patients <50 years being tested (15.15% in 2020, 26.49% in 2024 [ figure 1]). Performance varied by sex and age group. PPV was higher in males compared to females; 9.54% (95%CI: 9.09-10.01) versus 6.64% (95%CI: 6.27-7.03). This finding was consistent across all age strata. NNS was highest in females <50 years (38 [95%CI: 30-47]) and lowest in males ≥80 years (9 [95%CI: 8-10]).Conclusions Population-level data demonstrates that there is variation by age and sex in the performance of FIT at a binary threshold of ≥10 μgHb/g. Consideration of patient characteristics in addition to FIT result could improve risk stratification.Abstract O86 Figure 1Proportion of total FITs performed by age group from 2020 to March 2025 (n=240,127)