Supplementary Table 4.
Details Regarding Computation of the Screening Target Population and Expected Number of CRC Cases in Italy
| Italy macro-region | 50- to 69-year-old Italian total population | Target population | N invitations | N participants | N FIT+ | CRC |
|---|---|---|---|---|---|---|
| North | 7,727,209 | 3,863,605 | 3,670,424 | 1,908,621 | 89,705 | 1909 |
| Center | 3,342,758 | 1,671,379 | 1,504,241 | 526,484 | 27,904 | 790 |
| South-Islands | 5,619,474 | 2,809,737 | 1,264,382 | 303,452 | 21,849 | 486 |
| Total | 16,689,441 | 8,344,721 | 6,439,047 | 2,738,557 | 139,457 | 3184 |
NOTE. The Italian population data stratified by age are retrieved from the Italian National Statistics Institute (ISTAT) website (http://demo.istat.it/pop2019/index.html; last available data referring to January 1, 2019). In particular, we consider 3 macro-regions (North, Center, and South-Islands) and the 50 to 69 age class that is the target population of the screening program. Considering that the screening program is biennial, we compute the screening target population by halving the 50 to 69 age total population. As reported in Vicentini et al,30 there are differences in the Italian macro-regions in covering the target population (ie, sending invitations for screening), with 95% coverage in the North, 90% in the Center, and 45% in the South-Islands. Because of these percentages, we estimate a total of 6,439,047 sent invitations. The last report of the National Screening Observatory (https://www.osservatorionazionalescreening.it/content/lo-screening-colorettale; last available data referring to year 2017) provides information about the percentage of invited population that performed the FIT test (52% in the North, 35% in the Center, and 24% in the South-Islands) and the percentage of positive tests (4.7% in the North, 5.3% in the Center, and 7.2% in the South-Islands). We thus obtain a total of 2,738,557 participants and 139,457 positive tests. Moreover, because of a CRC detection rate (provided by the National Screening Observatory) equal to 1% (North), 1.5% (Center), and 1.6% (South-Islands), we estimate to have 3184 CRC cases in the whole year, corresponding to 2.28% of the estimated number of FIT+.
CRC, colorectal cancer; FIT, fecal immunochemical test.