Roel Bogie

Chapter 5

Results Prevalence of LNPCPs in the screening cohort

Patient andpolyp characteristics of both the national and regional screening cohort are provided in Tables 5.1 and 5.2 . In the national screening cohort, 124,155 patients underwent a colonoscopy after a positive FIT, and the prevalence of LNPCP patients was 8%. A total of 11,130 LNPCPs were found, of which 5788 (52%) were located in the proximal colon. The median size of LNPCPs was 25.0 mm (20-35), and 2053 (18%) were ≥40mm in size. This subgroup of LNPCPs (≥40mm) was evenly distributed over the proximal and distal colon (1039 vs. 1014, 51% vs. 49%), but mainly located in the rectosigmoid (882/2053, 43%) and right-sided colon segments (873/2053, 43%). Comparison of the national and regional cohort on patient, polyp, and colonoscopy characteristics confirmed that the regional cohort was a representative sample of the national cohort ( Tables 5.1 and 5.2 ). Although there were statistically significant differences in LNPCP prevalence, size, and morphology, these small differences were not considered clinically relevant.

Table 5.1: Patient characteristics in the national and regional cohort. | P value corresponds to the comparison of national cohort (2014-2017) versus regional cohort (2014-2015), unless stated otherwise (*).

National cohort Regional cohort 2014-2017 2014-2015 2014-2015 Overall patient characteristics n = 124 155 n = 68 471 n = 3085

P value

Age in years, mean (SD) Gender, female n (%) LNPCP patients, n (%)

67.4 (5.0)

68.0 (4.8)

68.2 (5.4) 1229 (40) 282 (9) 156 (10) 123 (8)

0.001 *0.098

49,502 (40)

27 328 (40)

0.944

9772 (8) 1910 (8) 3603 (8) 3964 (8)

5513 (8) 1910 (8) 3603 (8)

0.011 *0.034

2014 2015 2016

2017 (until February) 295 (7) LNPCP patient characteristics n = 9772 n = 5624 n = 282 Age in years, mean (SD) 67.8 (5.0) 68.1 (4.7) 68.5 (5.1)

0.006 *0.149

Gender, female n (%) ASA Classification, n (%) I

3520 (36)

1976 (35)

99 (35)

0.755

129 (46) 141 (50)

II

III IV

12 (4)

0

*statistical comparison between national cohort 2014-2015 and regional cohort 2014-2015

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