Result card

  • SAF10: Does the existence of harms influence tolerability or acceptability of FIT?

Does the existence of harms influence tolerability or acceptability of FIT?

Authors: Agnes Männik, Irena Guzina, Petra Jandova, Leonor Varela Lema, Gerardo Atienza Merino

Internal reviewers: Matthias Schwenkglenks, Ingrid Wilbacher

The domain literature search was used.

Wong et al {15} evaluated the factors associated with choosing immunochemical faecal occult blood test (FIT) or colonoscopy for colorectal cancer (CRC) screening among 3430 Chinese participants taken from a community-based cancer screening programme in Hong Kong and determined that the choice of the colonoscopy test was significantly influenced by the perceived discomfort induced by screening (OR 1.36, 95% CI 1.15–1.59, P < 0.001) . The findings show that those who did not perceive that CRC screening would inflict physical discomfort preferred colonoscopy. The update of this preliminary study {14}which includes 7845 patients also finds that the perception of the cancer screening being uncomfortable or embarrassing were associated with lower odds of choosing colonoscopy over FIT (p<0,001). The perception of risk did not significantly affect the choice of the tests.

Hol et al {12}compared the perceived test burden and acceptability of guaiac-based faecal occult blood test (gFOBT), faecal immunochemical test (FIT) and flexible sigmoidoscopy in a representative sample of the Dutch population randomly invited for the two tests and showed that FIT was perceived as slightly less burdensome than gFOBT due to less reported discomfort during faecal collection and test performance. The vast majority of participants would encourage friends or relatives to undertake either gFOBT or FIT (gFOBT: 96%, 95.8%; p=0.76) and were willing to attend a successive screening round (gFOBT: 94.1%, 94%; p=0.76). A significantly smaller proportion of FS screenees were willing to attend another round (83.8%; p< 0,005). The perceived risk of colorectal screening did not significantly influence the recommendation to friends and/or relatives, or the willingness to return for a successive screening round.

The results of 4 focal groups (n=28) set up to explore the perceptions of colorectal cancer and fecal immunochemical testing among African Americans in a north Carolina Community {11} showed that negative attitudes about FIT were mostly due to embarrassment when returning samples. The multistep instructions were also acknowledged as a potential problem for uptake.

The comparison of the uptake of FIT and gFOBT in 5,464 and 10,668 randomized eligible participants in a screening programme in the Clalit Health Service (Israel) {10} showed that compliance in taking the kits was better (but not statistically significantly better) with gFOBT  (37.8% vs. 29.3%; OR 1.43 [95% CI 0.73–2.80]; P = 0.227). Independent factors associated with increased compliance were female gender, age ≥ 60 years and immigrant status.

The evidence is insufficient in quantity and quality to establish how the existence of perceived harms influences acceptability or tolerability. The findings suggest that the factor that influences acceptability is not so much risk perception but the discomfort of the test procedures {12, 14, 15}. The preference of FIT over colonoscopy can be influenced by the perceived discomfort and embarrassment associated with the latter but there seems to be many other factors involved, like age, educational level, occupational status or family history of colorectal cancer, that should be further explored {14}.

Even though the fewer number of faecal samples required for FIT with respect to gFOBT seems to lead to less discomfort during faecal collection, as the gFOBT has to be performed on three consecutive bowel movements and FIT is a one-sample test, evidence suggests that both tests are equally tolerable {12}. Both tests seem to be equally recommended to their family and/or friends by screening participants but it is not clear how this and other differences, like kit presentation, can influence the acceptance of both tests. Whilst some studies suggest that participation could be similar or even slightly higher with gFOBT {10}, others enhance that patients receiving immunochemical kits are approximately twice as likely to participate than those receiving the guaiac kit {13}. It would be reasonable to think that persons would prefer the user-friendly characteristics of the immunochemical test (more convenient, less messy, no dietary restrictions) but it must be acknowledged that these tests may be challenging to some people and thus acceptance could depend on the setting {11, 13}.

Männik A et al. Result Card SAF10 In: Männik A et al. Safety In: Jefferson T, Cerbo M, Vicari N [eds.]. Fecal Immunochemical Test (FIT ) versus guaiac-based fecal occult blood test (FOBT) for colorectal cancer screening [Core HTA], Agenas - Agenzia nazionale per i servizi sanitari regionali; 2014. [cited 16 June 2021]. Available from: