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Introduction Uptake is an important determinant of the effectiveness of population-based screening. Uptake of colorectal cancer (CRC) screening generally remains sub-optimal. Aim To determine factors influencing the decision whether to participate or not among individuals invited for faecal occult blood test (FOBT) or flexible sigmoidoscopy (FS) screening. Methods A questionnaire was sent to a stratified random sample of individuals aged 50–74, previously invited for a randomised CRC screening trial offering FOBT or FS, and a reference group from the same population not previously invited (screening naive group). The questionnaire assessed reasons for (non)-participation, individuals’ characteristics associated with participation, knowledge, attitudes and level of informed choice. Results The response rate was 75% ( n = 341/452) for CRC screening participants, 21% ( n = 676/3212) for non-participants and 38% ( n = 192/500) for screening-naive individuals. The main reasons for FOBT and FS participation were acquiring certainty about CRC presence and possible early CRC detection. Anticipated regret and positive attitudes towards CRC screening were strong predictors of actual participation and intention to participate in a next round. The main reason for non-participation in FOBT screening was lack of abdominal complaints. Non-participation in FS screening was additionally influenced by worries about burden. Eighty-one percent of participants and 12% of non-participants made an informed choice on participation. Conclusion Only 12% of non-participants made an informed choice not to participate. These results imply that governments and/or organizations offering screening should focus on adequately informing and educating target populations about the harms and benefits of CRC screening. This may impact uptake of CRC screening.

Objective The sensitivity and specificity of a single faecal immunochemical test (FIT) are limited. The performance of FIT screening can be improved by increasing the screening frequency or by providing more than one sample in each screening round. This study aimed to evaluate if two-sample FIT screening is cost-effective compared with one-sample FIT. Design The MISCAN–colon microsimulation model was used to estimate costs and benefits of strategies with either one or two-sample FIT screening. The FIT cut-off level varied between 50 and 200 ng haemoglobin/ml, and the screening schedule was varied with respect to age range and interval. In addition, different definitions for positivity of the two-sample FIT were considered: at least one positive sample, two positive samples, or the mean of both samples being positive. Results Within an exemplary screening strategy, biennial FIT from the age of 55–75 years, one-sample FIT provided 76.0–97.0 life-years gained (LYG) per 1000 individuals, at a cost of €259 000–264 000 (range reflects different FIT cut-off levels). Two-sample FIT screening with at least one sample being positive provided 7.3–12.4 additional LYG compared with one-sample FIT at an extra cost of €50 000–59 000. However, when all screening intervals and age ranges were considered, intensifying screening with one-sample FIT provided equal or more LYG at lower costs compared with two-sample FIT. Conclusion If attendance to screening does not differ between strategies it is recommended to increase the number of screening rounds with one-sample FIT screening, before considering increasing the number of FIT samples provided per screening round.

Objective Colorectal cancer screening by means of faecal immunochemical tests (FITs) requires successive screening rounds for an optimal preventive effect. However, data on the influence of the length of the screening interval on participation and diagnostic yield are lacking. Repeated FIT screening was therefore performed in a population-based trial comparing various repeat intervals. Design 7501 Dutch individuals aged 50–74 years were randomly selected and invited for two 1-sample FIT screening rounds (haemoglobin (Hb) concentration ≥50 ng/ml, corresponding to 10 μg Hb/g faeces) with intervals of 1 (group I), 2 (group II) or 3 years (group III). Results In group I, participation was 64.7% in the first screening round and 63.2% in the second. The corresponding percentages for groups II and III were 61.0% vs 62.5% and 62.0% vs 64.0%. Triennial screening resulted in a higher participation rate in the second screening round compared with annual screening (p=0.04). The overall positivity rate in the second screening round was significantly lower compared with the first round (6.0% vs 8.4%; OR 0.69, 95% CI 0.58 to 0.82) and did not depend on interval length (p=0.23). Similarly, the overall detection rate of advanced neoplasia was significantly lower in the second round compared with the first screening round (1.9% vs 3.3%; OR 0.57, 95% CI 0.43 to 0.76) and also did not depend on interval length (p=0.62). The positive predictive value of the FIT did not significantly change over time (41% vs 33%; p=0.07). Conclusion The total number of advanced neoplasia found at repeat FIT screening is not influenced by the interval length within a range of 1–3 years. Furthermore, there is a stable and acceptably high participation in the second screening round. This implies that screening intervals can be tailored to local resources.

Fecal immunochemical tests (FIT) are preferred over guaiac-based fecal occult blood testing as colorectal cancer (CRC) screening tool. However, hemoglobin (Hb) degradation over time may influence FIT outcome. We therefore evaluated the effect of sample return time on FIT performance characteristics in a population-based CRC screening trial.A representative random sample of the Dutch population (n=17,677), aged 50-74 years, was invited for FIT screening (OC-Sensor Micro; cutoff ≥ 50 ng Hb/ml). Sample return time was defined as the interval in days between fecal sampling and FIT laboratory delivery. Moreover, a random sample of positive FITs were selected to be stored at room temperature and re-tested every 3-4 days.In total, 8,958 screenees fulfilled our inclusion criteria. The mean sample return time was 3 days (± 3). Overall, 792 screenees (8.8%) had a positive test. Between the sample return time groups, the positivity rate (PR) varied between 7.7 and 9.0%. No statistically significant associations were found between PR or detection rate (DR) and the different sample return time groups (P value=0.84 and 0.76, respectively). For the laboratory experiment, 71 positive FITs were stored at room temperature and re-tested with standard intervals. The mean daily fecal Hb decrease was 5.88% per day (95% confidence interval 4.78-6.96%). None of the positive FITs became negative before 10 days after fecal sampling.This population-based CRC screening trial demonstrates that both the PR and DR of FITs do not decrease with prolonged sample return times up to 10 days. This means that a delay in sending the FIT back to the laboratory, of up to at least 1 week, does not necessitate repeat sampling in case of a negative test result. These data support the use of FIT-based screening as a reliable tool for nationwide CRC screening programs.

Background: Perceived burden of colorectal cancer (CRC) screening is an important determinant of participation in subsequent screening rounds and therefore crucial for the effectiveness of a screening programme. This study determined differences in perceived burden and willingness to return for a second screening round among participants of a randomised population-based trial comparing a guaiac-based faecal occult blood test (gFOBT), a faecal immunochemical test (FIT) and flexible sigmoidoscopy (FS) screening. Methods: A representative sample of the Dutch population (aged 50-74 years) was randomised to be invited for gFOBT, FIT and FS screening. A random sample of participants of each group was asked to complete a questionnaire about test burden and willingness to return for CRC screening. Results: In total 402/481 (84%) gFOBT, 530/659 (80%) FIT and 852/1124 (76%) FS screenees returned the questionnaire. The test was reported as burdensome by 2.5% of gFOBT, 1.4% of FIT and 12.9% of FS screenees (comparing gFOBT versus FIT p = 0.05; versus FS p < 0.001). In total 94.1% of gFOBT, 94.0% of FIT and 83.8% of FS screenees were willing to attend successive screening rounds (comparing gFOBT versus FIT p = 0.84; versus FS p < 0.001). Women reported more burden during FS screening than men (18.2% versus 7.7%; p < 0.001). Conclusions: FIT slightly outperforms gFOBT with a lower level of reported discomfort and overall burden. Both FOBTs are better accepted than FS screening. All three tests have a high level of acceptance, which may affect uptake of subsequent screening rounds and should be taken into consideration before implementing a CRC screening programme. (C) 2010 Elsevier Ltd. All rights reserved.

Background: Screening for colorectal cancer (CRC) is widely accepted, but there is no consensus on the preferred strategy. We conducted a randomised trial comparing participation and detection rates (DR) per screenee of guaiac-based faecal occult blood test (gFOBT), immunochemical FOBT (FIT), and flexible sigmoidoscopy (FS) for CRC screening. Methods: A representative sample of the Dutch population (n = 15 011), aged 50–74 years, was 1:1:1 randomised prior to invitation to one of the three screening strategies. Colonoscopy was indicated for screenees with a positive gFOBT or FIT, and for those in whom FS revealed a polyp with a diameter ⩾10 mm; adenoma with ⩾25% villous component or high grade dysplasia; serrated adenoma; ⩾3 adenomas; ⩾20 hyperplastic polyps; or CRC. Results: The participation rate was 49.5% (95% confidence interval (CI) 48.1 to 50.9%) for gFOBT, 61.5% (CI, 60.1 to 62.9%) for FIT and 32.4% (CI, 31.1 to 33.7%) for FS screening. gFOBT was positive in 2.8%, FIT in 4.8% and FS in 10.2%. The DR of advanced neoplasia was significantly higher in the FIT (2.4%; OR, 2.0; CI, 1.3 to 3.1) and the FS arm (8.0%; OR, 7.0; CI, 4.6 to 10.7) than the gFOBT arm (1.1%). FS demonstrated a higher diagnostic yield of advanced neoplasia per 100 invitees (2.4; CI, 2.0 to 2.8) than gFOBT (0.6; CI, 0.4 to 0.8) or FIT (1.5; CI, 1.2 to 1.9) screening. Conclusion: This randomised population-based CRC-screening trial demonstrated superior participation and detection rates for FIT compared to gFOBT screening. FIT screening should therefore be strongly preferred over gFOBT screening. FS screening demonstrated a higher diagnostic yield per 100 invitees than both FOBTs.

BACKGROUND & AIMS: Fecal immunochemical tests (FITs) are used widely in colorectal cancer screening. Programs use the same fecal hemoglobin threshold for colonoscopy referral for men and women, but it is unclear whether FIT performs equally in both sexes. We therefore assessed FIT performance in men and women. METHODS: A prospective cohort study was performed, in which a total of 10,008 average-risk subjects (age, 50-74 y) were invited for first-round screening and 8316 average-risk subjects (age, 51-74 y) were invited for second-round screening with a single FIT. Subjects with a hemoglobin (Hb) level of 10 mg hemoglobin (Hb)/g (or >= 50 ng/mL) feces or higher were referred for colonoscopy. The test characteristics were assessed by sex for a range of FIT cut-off values. RESULTS: In total, 59.8% of men and 64.6% of women participated in the first round (P < .001). At a cut-off level of 10 mg Hb/g feces, the positivity rate was significantly higher among men (10.7%) compared with women (6.3%; P < .001) in the first round. The detection rate of advanced neoplasia was 4.4% for men and 2.2% for women (P < .001) in the first round. The positive predictive value for advanced neoplasia in the first round was 42% for men and 37% for women (P = .265). A significantly higher false-positive rate in men (6.3%) than in women (4.1%; P < .001) was found. Similar differences in these test characteristics were seen in the second round. CONCLUSIONS: At a cut-off level of 10 mg Hb/g feces the FIT positivity rate was higher in men, reflected by both a higher detection rate and a higher false-positive rate. The use of the same cut-off value in men and women in FIT screening is recommended based on equal test performance in terms of positive predictive value.

BACKGROUND & AIMS: The fecal immunochemical test (FIT) is superior to the guaiac-based fecal occult blood test in detecting neoplasia. There are not much data on the optimal number of FITs to perform. We conducted a population-based trial to determine attendance and diagnostic yield of 1- and 2-sample FIT screening.METHODS: The study included 2 randomly selected groups of subjects aged 50-74 years (1-sample FIT, n=5007; 2-sample FIT, n=3197). The 2-sample group was instructed to collect fecal samples on 2 consecutive days. Subjects were referred for colonoscopy when at least 1 sample tested positive (≥50 ng hemoglobin/mL).RESULTS: Attendance was 61.5% in the 1-sample group (2979 of 4845; 95% confidence interval, 60.1%-62.9%) and 61.3% in the 2-sample group (1875 of 3061; 95% confidence interval, 59.6%-63.0%; P=.84). In the 1-sample group 8.1% tested positive, and in the 2-sample group 12.8% had at least 1 positive test outcome and 5.0% had 2 positive test outcomes (PCONCLUSIONS: There is no difference in attendance for subjects offered 1- or 2-sample FIT screening. The results allow for the development of efficient FIT screening strategies that can be adapted for local colonoscopy capacities, rather than varying the cut-off value in a 1-sample strategy.

Objective. The population benefit of screening depends not only on the effectiveness of the test, but also on adherence, which, for colorectal cancer (CRC) screening remains low. An advance notification letter may increase adherence, however, no population-based randomized trials have been conducted to provide evidence of this. Method. In 2008, a representative sample of the Dutch population (aged 50-74 years) was randomized. All 2493 invitees in group A were sent an advance notification letter, followed two weeks later by a standard invitation. The 2507 invitees in group B only received the standard invitation. Non-respondents in both groups were sent a reminder 6 weeks after the invitation. Results. The advance notification letters resulted in a significantly higher adherence (64.4% versus 61.1%, p-value 0.019). Multivariate logistic regression analysis showed no significant interactions between group and age, sex, or socio-economic status. Cost analysis showed that the incremental cost per additional detected advanced neoplasia due to sending an advance notification letter was (sic)957. Conclusion. This population-based randomized trial demonstrates that sending an advance notification letter significantly increases adherence by 3.3%. The incremental cost per additional detected advanced neoplasia is acceptable. We therefore recommend that such letters are incorporated within the standard CRC-screening invitation process. (C) 2011 Elsevier Inc. All rights reserved.

Immunochemical faecal occult blood testing (FIT) provides quantitative test results, which allows optimisation of the cut-off value for follow-up colonoscopy. We conducted a randomised population-based trial to determine test characteristics of FIT (OC-Sensor micro, Eiken, Japan) screening at different cut-off levels and compare these with guaiac-based faecal occult blood test (gFOBT) screening in an average risk population. A representative sample of the Dutch population (n=10 011), aged 50-74 years, was 1 : 1 randomised before invitation to gFOBT and FIT screening. Colonoscopy was offered to screenees with a positive gFOBT or FIT (cut-off 50 ng haemoglobin/ml). When varying the cut-off level between 50 and 200 ng ml(-1), the positivity rate of FIT ranged between 8.1% (95% CI: 7.2-9.1%) and 3.5% (95% CI: 2.9-4.2%), the detection rate of advanced neoplasia ranged between 3.2% (95% CI: 2.6-3.9%) and 2.1% (95% CI: 1.6-2.6%), and the specificity ranged between 95.5% (95% CI: 94.5-96.3%) and 98.8% (95% CI: 98.4-99.0%). At a cut-off value of 75 ng ml(-1), the detection rate was two times higher than with gFOBT screening (gFOBT: 1.2%; FIT: 2.5%; P