Comparison of the yield from two faecal immunochemical tests at identical cutoff concentrations – a randomized trial in Latvia Daiga Santare a , Ilona Kojalo a , Inta Liepniece-Karele a , Ilze Kikuste d , Ivars Tolmanis e , Inese Polaka b , Uldis Vikmanis b , Viesturs Boka a and Marcis Leja c Objective We have compared the performance of two faecal immunochemical tests (FIT) in an average-risk population. Materials and methods Altogether, 10 000 individuals aged 50–74 were selected randomly from the population of Latvia in 2011 and assigned randomly either to OC-Sensor or to FOB Gold single-time testing. Positivity of the test, frequency of colonic lesions, number needed to screen (NNscreen) and scope for the detection of an advanced neoplasm (cancer and advanced adenoma) were compared between the tests using the same cutoff concentrations in μg/g faeces. Confidence intervals (CIs) at 95% were calculated. Results Positivity with the cutoff set at 10 μg/g faeces was 12.8% (95% CI: 11.4–14.2) for FOB Gold and 8.3% (95% CI: 7.2–9.4) for OC-Sensor (P < 0.001). Positivity was higher in men and the older age groups. Colonoscopy compliance was 55.5%. There was no significant difference between the two tests at comparable cutoff concentrations in μg/g, colonoscopy attendance rate or colonoscopy results. For advanced neoplasm detection, there was no significant difference in number needed to scope and NNscreen at a cutoff of 10 μg/g faeces; however, lower NNscreen was required to detect advanced neoplasms with the FOB Gold test at increased cutoff concentrations. Conclusion Different quantitative FIT systems may report different positivity rate at identical cutoff concentrations, which has to be considered when implementing the use of FIT in national screening programmes. Eur J Gastroenterol Hepatol 28:904–910 Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Introduction A laboratory-based quantitative faecal immunochemical test (FIT), with a user-defined adjustable cutoff con- centration for a positive test result interpretation, is cur- rently the test of choice for colorectal cancer (CRC) screening in Europe [1]. Accordingly, two test systems corresponding to this description are listed in the European guidelines [1] – FOB Gold or OC-Sensor. Depending on available resources, several approaches can be used to identify the individuals at risk who need to be referred for colonoscopy. This includes the cutoff values for defining the test result as positive and the number of stool samples to be analysed [2]. Different test types could also have a different yield [3]. Several tests, including FIT, can have different char- acteristics, including the volume of the buffer in the sample collection tubes and even the sample weight used for the test [4]. Previously used measurement concentration – nanograms of haemoglobin per ml of buffer (ng/ml) do not consider these potential variables. Therefore, the use of these units has been discouraged and the recommended measurement units are μg haemoglobin per gram faeces (μg/g) [5,6]. For evaluation purposes, comparable units are important. To date, few studies have compared the yield of dif- ferent FIT systems in the identification of high-risk colon neoplasms and the differences between the tests in the need for colonoscopies. A comparison is also needed within comparable populations, optimally in a randomized study. Therefore, we have analysed the yield of OC-Sensor and FOB Gold at different cutoff concentrations in finding high-risk lesions and the required number of colonoscopies within the different FIT testing scenarios. Materials and methods Ethics approval The study was approved on 15 December 2010 by the Central Medical Ethics Committee of Latvia, protocol NA-10. Study population Two groups of individuals, each group including 5000 individuals aged 50–74 years, were selected randomly from the Latvian Population Registry in 2011. The population of the country has a European average risk of a Department of Medicine, Riga East University Hospital, b Department of Medicine, University of Latvia, c Department of Medicine, Riga East University Hospital, University of Latvia, Digestive Diseases Centre Gastro, d Digestive Diseases Centre Gastro and e Digestive Diseases Centre Gastro, Riga Stradins University, Riga, Latvia Correspondence to Daiga Santare, MSc, Department of Medicine, University of Latvia, Raina Blvd. 19, Riga LV1586, Latvia Tel: + 371 292 21107; fax: + 371 670 40367; e-mail: daiga.santare@inbox.lv Received 30 December 2015 Accepted 14 March 2016 European Journal of Gastroenterology & Hepatology 2016, 28:904–910 Keywords: advanced neoplasm, colonoscopy, colorectal cancer screening, cutoff, faecal immunochemical test ’ Original article 0954-691X Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/MEG.0000000000000650 904 Copyright r 2016 Wolters Kluwer Health, Inc. All rights reserved.