Prescreening evaluation of a brush-based faecal immunochemical test for haemoglobin

Current diagnostic tools for colorectal cancer rely on stool-based immunochemical tests. While these methods are widely used, there is limited understanding of how sampling techniques affect test accuracy and patient compliance. Prior research has shown that spatula-based sampling is standard, but questions remain about alternative methods. No prior work had resolved whether brush-based sampling could match or exceed spatula methods in diagnostic performance. This gap motivated an investigation into whether a new brush-based test could maintain diagnostic accuracy while improving user preference. Existing studies have not fully compared brush versus spatula sampling for faecal immunochemical tests. That uncertainty drove the need for a direct comparison of these two approaches. This study aimed to address that gap by evaluating a novel brush-based test alongside an established spatula-based test.

This study aimed to compare a new brush-based faecal immunochemical test with a traditional spatula-based test for detecting haemoglobin. The goal was to assess whether the brush method could match the spatula method in diagnostic accuracy while being more user-friendly. The study focused on patients scheduled for colonoscopy, allowing direct comparison against a gold-standard diagnostic. Researchers wanted to determine if brush sampling could detect cancer and adenomas as effectively as the spatula method. The motivation was to identify a potentially more acceptable alternative for patients undergoing screening. The study also sought to evaluate whether brush sampling could distinguish between different levels of neoplasia. No prior work had directly compared these two sampling methods in a diagnostic setting. This comparison could inform future screening protocols and patient preferences.

The study involved patients aged 24 to 90 who were scheduled for colonoscopy. Participants provided three stool samples using a spatula and two using a brush. The order of sampling was randomised to avoid bias. Both the FlexSure and InSure tests were used to detect faecal haemoglobin. A subset of samples was tested using a modified InSure method to assess discrimination between neoplastic and normal groups. Sensitivity and false-positive rates were calculated for cancer and adenoma detection. Patient preference was measured via a survey after sampling. The study design allowed direct comparison of test performance and user experience. This approach ensured that both diagnostic accuracy and patient feedback were evaluated systematically.

The brush-based InSure test showed a sensitivity of 75% for cancer detection, compared to 80.5% for the spatula-based FlexSure. For large adenomas, InSure detected 41.4%, while FlexSure detected 44.8%. Both methods had similar false-positive rates in normal patients: 2.2% for InSure and 2.8% for FlexSure. Patients with cancer had the highest faecal haemoglobin levels, followed by those with adenomas. Normal patients had significantly lower levels than those with neoplasia. The brush method was preferred by 82.6% of participants, while only 8.7% preferred the spatula. This preference difference was statistically significant (p<0.00001). The results suggest that InSure is as accurate as FlexSure while being more user-friendly.

The authors concluded that the brush-based InSure test is as sensitive and specific as the traditional spatula-based FlexSure test for detecting faecal haemoglobin. Both methods showed similar diagnostic performance for cancer and adenomas. The study found no significant difference in sensitivity or false-positive rates between the two tests. The brush method was preferred by the majority of participants, indicating a potential advantage in patient compliance. The authors propose that the InSure test allows discrimination between normal and neoplastic groups. They suggest that this brush-based test should now be evaluated in a broader screening population. The findings support the use of InSure as a viable alternative to spatula-based sampling. The authors did not claim that the brush method is essential but noted its high preference and diagnostic equivalence.