This result card deals with how patients react upon Fit and gFobt both in terms of compliance with the two tests and participation to the screening and in terms of patients’ preferences, satisfaction, perceptions of the pros and cons of having one tests or the other. Seven (7) of our included records provided data on participation to a screening program with Fit and/or gFOBT and compliance with those tests: systematic reviews by Vart et al. (2012) and Hassan et al (2012), and 5 primary studies that were not included in the Vart et al.’s review (Hughes 2005, Federici, 2005, Hol. L., V. de Jonge et al. 2010, Hol, van Leerdam M.E. 2010, Birkenfeld 2011). Specifically the study by Hol. L., V. de Jonge et al. 2010, gives an insight to aspects related to preferences and satisfaction with the tests. Below a detailed descriptions of the above studies is provided for the participation/compliance item and for the satisfaction/preferences topic.
Systematic review by Vart et al (2012) is namely about comparing participation rates between Fit and gFOBT. According to Vart et al. overall the participation rate was found to be significantly higher with FIT than with g-FOBT. Vart highlights that only Levi et al. (2011) reported a better compliance for g-FOBt, but context specific variables (related to hot climate in Israel causing a more complex procedure to store stools) with FiT could help to explain this diversity. Vart et al explains that notwithstanding this heterogeneity among studies, since six out of the seven included studies drew similar conclusions, authors thought a meta-analysis was useful and justified because it increased the statistical precision of the point estimate.
Authors highlight that all studies included in the meta-analysis defined the “participation rate” as the “number of completed test kits returned”. Three studies specified a time line for participation rates, i.e. number of test kits returned within 12 weeks (Cole et al., 2003), within 90 days of the participant agreeing to take part in the study (Hoffman et al., 2010), or the number of participants returning a gFOBT by the end of the study (van Rossum et al., 2008).
Four studies reported the use of reminders sent to non-responders 2 weeks (van Rossum et al., 2008); 6 weeks (Cole et al., 2003; Hol et al., 2009) and 8 weeks (Hughes et al., 2005) after the initial invitation, if a completed kit had not been returned. When the seven studies were pooled together, the participation rate was significantly higher in the FIT groups (48.1%) than in the G-FOBT (39.2%) groups (RR 1.21; 95% CI 1.09–1.33) with a quite large heterogeneity within studies (I2=95%) (See below). Authors’ conlcusions support hypothesis that the implementation of FIT test instead of gFOBT is likely to increase participation in CRC screening.
Forest Plot by Vart et al. meta-analysis (Vart et al. 2012, p.91)
Birkenfeld et al. 2011 is a Israeli study and its results does not show the same huge diversity due to context specific variables of the other Israeli study by Levi et al (see the Forest Polt in Fig.1). In this study there were 5,464 and 10,668 eligible participants in the FIT and gFOBT arms respectively. Compliance in taking the kits was better (but not statistically significantly better) with gFOBT (37.8% vs 29.3%; odds ratio [OR] 1.43 [95% CI 0.73–2.80]; P ¼ 0.227). Authors themselves tried to give an explanation of their out of line results. Their design was indeed much more demanding for the FIT arm than for the gFOBT one although the latter provided the usual dietary restrictions. The Fit arm had indeed to take three samples, keeping them in the refrigerator and bring the samples back using cooling bags. This more demanding procedure was related to the hot climate in Israel that could degraded samples taken with FIT. Anyways Kit return was higher in the FIT arm (65.0% vs. 78.9%; OR 0.45 [95% CI 0.24–0.83], P ¼ 0.021) and the overall uptake of gFOBT and FIT was comparable (OR 0.996 [95% CI 0.46–2.17], P ¼ 0.99).
In the other systematic review performed by Hassan et al. the aim was to compare the participation rates among different CRC screening options and to assess the effect of such differences on the detection rates of advanced neoplasia. Indeed authors themselves highlights that the effectiveness of a screening depends not only on the sensitivity for colorectal neoplasia but also on population attendance. Thus the impact of adherence and compliance on the effectiveness of a screening strategy is paramount and a low participation diminish the efficacy of a CRC screening as a whole.
Their study specifically aimed to address two questions. The first is related to our topic, as authors aim at understanding if, when equally offered to a screening population, the screening tests differ with regard to adherence to the CRC screening. To answer this question, Hassan et al. meta-analysed 5 studies (see fig. 2) about attendance rate with g-FOBT vs. FIT. Final results showed that FIT resulted in a higher uptake compared with g-FOBT (RR: 1.16; 95% CI: 1.03, 1.3). Authors highlight that inter-study heterogeneity (I2) was 96% and that such heterogeneity appeared to be related only to one series (the already mentioned Levi et al study). The exclusion of Levi’s was shown to result in a I2 equal to 0%. The detection rate for advanced neoplasia and cancer with FIT was also superior to g-FOBT at both PP (RR: 1.94, 95% CI: 1.37, 2.76, I2: 56%; RR: 1.67, 95% CI: 1.01, 2.8, I2: 0%) and ITT analyses (RR: 2.28, 95% CI: 1.68, 3.10, I2: 43%; RR: 1.96, 95% CI: 1.2, 3.2, I2: 0%).
Forest Plot by Hassan et al. meta-analysis (Hassan et al. 2012, p.935)
Federici et al. (2005) conducted a cluster-randomized trial to evaluate the effect of the type of test (gFOBT vs FIT) on screening compliance. The principal outcome was the percentage of returned tests. A sample og 130 general practitioners who consented to participate in the trial was selected. A sample of GP’s patients 50 –75-year-old were then randomly divided into 2 groups: one to be screened at the GP’s office and the other to the nearest gastroenterology ward. The FIT test had a compliance of 35.8% and the guaiac of 30.4% (relative risk [RR] 1.20; 95% confidence interval [CI] 1.02–1.44). The difference was mostly due to a higher probability of returning the sample: 93.8% and 88.6% for immunochemical and guaiac, respectively (RR 1.06; 95% CI 1.02–1.10). Authors stated that compliance is more likely with FIT than gFOBT, and this difference is independent of the provider.
In the study by Hughes et al. (2005) conducted in a small, rural community of the north Queensland (USA), overall, 1,219 kits were completed and returned for analysis. Participation was significantly higher with the immunochemical kit (χ2=20.7, p<0.00). In accordance with bivariate results, persons receiving an immunochemical kit were approximately twice as likely to participate than those receiving a guaiac kit.
The Dutch population-based randomised screening trial described by Hol L., Van Leerdam ME - 2010 involved a random sample of the Dutch population aged 50–74 years that was asked to participate in a randomised screening trial. Of the 15 011 subjects who were randomised prior to invitation to one of the three tests 670 were excluded from analysis (4.5%; 608 subjects met one of the exclusion criteria, 43 had moved away and 19 had died). The overall participation rate was 48.0% (CI, 47.1 to 48.7%). In total, 49.5% (CI, 48.1% to 50.9%) attended gFOBT, 61.5% (CI, 60.1% to 62.9%) FIT and 32.4% (CI, 31.1% to 33.7%) FS screening. This demonstrated a 12% higher participation rate to FIT than gFOBT screening.
In the study by Hol. L., V. de Jonge et al. 2010, authors describe results of the survey about the “perceived burden” of FIT, gFOBT and FS, which was undertaken involving the same cohort of people of Hol L., Van Leerdam ME (2010) and Hol L.(2009)..Durimg the Dutch population-based randomised screening trial (described by Hol L., Van Leerdam ME - 2010) a further random sample of screenees (481 gFOBT participants, 659 FIT participants and 1124 FS participants) was asked to participate in the questionnaire study on acceptance and burden of the screening test they underwent. Patients who used gFOBT and FIT were asked to complete a single questionnaire 1 week after the test was received at the laboratory, but before the screened received the test result. Embarrassment and discomfort resulting were measured by three separate items that were adapted from earlier studies and related to three stages of the procedure (collecting faeces, performance of the test and returning the test to the laboratory), each with three response options (not, quite or very embarrassing/unpleasant ).
For the “Embarrassment, discomfort, and pain” issue, respondents rated “overall embarrassment” during gFOBT and FIT equally (0.07 versus 0.06; p = 0.30). A larger proportion of gFOBT than FIT screenees described the test as “uncomfortable” (0.15 versus 0.11; p = 0.02) due to more discomfort while collecting faeces and performing the test. For “Overall acceptance” significantly less FIT than gFOBT described the test as burdensome(p = 0.05), whereas FS was more often reported to be burdensome than gFOBT (p < 0.001) and FIT (p < 0.001). According to authors, FIT slightly outperforms gFOBT with a lower level of reported discomfort and overall burden.