Socioeconomic differences in participation and diagnostic yield within the Dutch national colorectal cancer screening programme with faecal immunochemical testing.

BACKGROUND: CRC mortality rates are higher for individuals with a lower socioeconomic status (SES). Screening could influence health inequalities. We therefore aimed to investigate SES differences in participation and diagnostic yield of FIT screening. METHODS: All invitees in 2014 and 2015 in the Dutch national CRC screening programme were included in the analyses. We used area SES as a measure for SES and divided invitees into quintiles, with Quintile 1 being the highest SES. Logistic regression analysis was used to compare the participation rate, positivity rate, colonoscopy uptake, positive predictive value (PPV) and detection rate across the SES groups. RESULTS: Participation to FIT screening was significantly lower for Quintile 5 (67.0%) compared to the other Quintiles (73.0% to 75.1%; adjusted OR quintile 5 versus quintile 1: 0.73, 95%CI: 0.72-0.74), as well as colonoscopy uptake after a positive FIT (adjusted OR 0.73, 95%CI: 0.69-0.77). The detection rate per FIT participant for advanced neoplasia gradually increased from 3.3% in Quintile 1 to 4.0% in Quintile 5 (adjusted OR 1.20%, 95%CI 1.16-1.24). As a result of lower participation, the yield per invitee was similar for Quintile 5 (2.04%) and Quintile 1 (2.00%), both being lower than Quintiles 2 to 4 (2.20%-2.28%). CONCLUSIONS: Screening has the potential to reduce health inequalities in CRC mortality, because of a higher detection in participants with a lower SES. However, in the Dutch screening programme, this is currently offset by the lower participation in this group.

Incidence of Interval Colorectal Cancer After Negative Results From First-Round Fecal Immunochemical Screening Tests, by Cutoff Value and Participant Sex and Age.

BACKGROUND & AIMS: We evaluated the incidence of interval cancers between the first and second rounds of colorectal cancer (CRC) screening with the FOB-Gold fecal immunochemical test (FIT), and the effects of different cutoff values and patient sex and age. METHODS: We collected data from participants in a population-based CRC screening program in the Netherlands who had a negative result from a first-round of FIT screening. We calculated the cumulative incidence of interval cancer after a negative result from a FIT and the sensitivity of the FIT for detection of CRC at a low (15 µg Hb/g feces) and high (47 µg Hb/g feces) cutoff value. RESULTS: Among the 485,112 participants with a negative result from a FIT, 544 interval cancers were detected; 126 were in the 111,800 participants with negative results from a FIT with the low cutoff value and 418 were in the 373,312 FIT participants with negative results from a FIT with the high cutoff value. The mean age of participants tested with the low cutoff value was 72.0 years and the mean age of participants tested the high cutoff value was 66.7 years. The age-adjusted 2-year cumulative incidence of interval cancer after a negative result from a FIT were 9.5 per 10,000 persons at the low cutoff value vs 13.8 per 10,000 persons at the high cutoff value (P < .005). The age-adjusted sensitivity of the FIT for CRC were 90.5% for the low cutoff value vs 82.9% for the high cutoff (P < .0001). The FIT identified men with CRC with 87.4% sensitivity and women with CRC with 82.6% sensitivity (P < .001). CONCLUSIONS: In an analysis of data from a FIT population-based screening program in the Netherlands, we found that incidence of interval CRC after a negative result from a FIT to be low. Although the sensitivity of detection of CRC decreased with a higher FIT cutoff value, it remained above 80%.

Quality Monitoring of a FIT-Based Colorectal Cancer Screening Program.

BACKGROUND: Quality assessment is crucial for consistent program performance of colorectal cancer (CRC) screening programs using fecal immunochemical test for hemoglobin (FIT). However, literature on the consistency of FIT performance in laboratory medicine was lacking. This study examined the consistency of FIT in testing positive or detecting advanced neoplasia (AN) for different specimen collection devices, lot reagents, and laboratories. METHODS: All participants with a FIT sample with a cutoff concentration of 47 µg Hb/g feces in the Dutch CRC screening program in 2014 and 2015 were included in the analyses. Multivariable logistic regression analyses were performed to estimate the odds ratios of collection devices, reagents, and laboratories on testing positive or detecting AN and positive predictive value (PPV). RESULTS: In total, 87519 (6.4%) of the 1371169 participants tested positive. Positivity rates and detection rates of AN differed between collection devices and reagents (all P < 0.01). In contrast, PPVs were not found to vary between collection devices, reagents, or laboratories (all P > 0.05). Positivity rates showed a small difference for laboratories (P = 0.004) but not for detection rates of AN. Size of the population affected by the deviating positivity rates was small (0.1% of the total tested population). CONCLUSIONS: Variations were observed in positivity and detection rates between collection devices and reagents, but there was no detected variation in PPV. Although the overall population effect of these variations on the screened population is expected to be modest, there is room for improvement.

Real-Time Monitoring of Results During First Year of Dutch Colorectal Cancer Screening Program and Optimization by Altering Fecal Immunochemical Test Cut-Off Levels.

BACKGROUND & AIMS: After careful pilot studies and planning, the national screening program for colorectal cancer (CRC), with biennial fecal immunochemical tests (FITs), was initiated in The Netherlands in 2014. A national information system for real-time monitoring was developed to allow for timely evaluation. Data were collected from the first year of this screening program to determine the importance of planning and monitoring for optimal screening program performance. METHODS: The national information system of the CRC screening program kept track of the number of invitations sent in 2014, FIT kits returned, and colonoscopies performed. Age-adjusted rates of participation, the number of positive test results, and positive predictive values (PPVs) for advanced neoplasia were determined weekly, quarterly, and yearly. RESULTS: In 2014, there were 741,914 persons invited for FIT; of these, 529,056 (71.3%; 95% CI, 71.2%-71.4%) participated. A few months into the program, real-time monitoring showed that rates of participation and positive test results (10.6%; 95% CI, 10.5%-10.8%) were higher than predicted and the PPV was lower (42.1%; 95% CI, 41.3%-42.9%) than predicted based on pilot studies. To reduce the burden of unnecessary colonoscopies and alleviate colonoscopy capacity, the cut-off level for a positive FIT result was increased from 15 to 47 µg Hb/g feces halfway through 2014. This adjustment decreased the percentage of positive test results to 6.7% (95% CI, 6.6%-6.8%) and increased the PPV to 49.1% (95% CI, 48.3%-49.9%). In total, the first year of the Dutch screening program resulted in the detection of 2483 cancers and 12,030 advanced adenomas. CONCLUSIONS: Close monitoring of the implementation of the Dutch national CRC screening program allowed for instant adjustment of the FIT cut-off levels to optimize program performance.

The value of models in informing resource allocation in colorectal cancer screening: the case of The Netherlands.

In May 2011, the Dutch government decided to implement a national programme for colorectal cancer (CRC) screening using biennial faecal immunochemical test screening between ages 55 and 75. Decision modelling played an important role in informing this decision, as well as in the planning and implementation of the programme afterwards. In this overview, we illustrate the value of models in informing resource allocation in CRC screening using the role that decision modelling has played in the Dutch CRC screening programme as an example.

[Faecal occult blood test for colorectal cancer screening: high quality for a good price]. / Ontlastingstest bevolkingsonderzoek darmkanker: goede kwaliteit tegen een goede prijs.

The Dutch National Institute for Public Health and the Environment (RIVM) awarded the immunochemical faecal occult blood test (IFOBT) to FOB Gold of Sentinel following a European call for tenders. The contract-awarding procedure included the application of quality knock-out criteria, which were met by two suppliers. The decisive factor was the best price/quality ratio. A recent review indicated that, at present, no single IFOBT is better than any other. The decision to opt for a test manufactured by a different supplier than was used in the previous screening pilots made it necessary to re-determine the cut-off value. This value has now been set (88 ng/ml) and is confirmed by a laboratory test. Colonoscopy-related capacity planning, as well as its diagnostic yield, depends on numerous factors; therefore, the RIVM is currently monitoring the referral percentage and number of adenomas detected and is collaborating on quality terms. Any necessary adjustments are to be made during the introduction of the screening test.