Table 3 Estimated positive predicted value and number needed for colonoscopy for CRC, AA and adenomas by f-Hb thresholds (μg/g) and interscreening intervals (years).

From: Impact of changes to the interscreening interval and faecal immunochemical test threshold in the national bowel cancer screening programme in England: results from the FIT pilot study

Threshold

Interscreening interval

Screen-detected CRC

Screen-prevented CRC

Screen-benefited CRC

AA detected

Adenomas

PPV

NNC

PPV

NNC

PPV

NNC

PPV

NNC

PPV

NNC

20

1

1.22%

82.1

0.61%

164.3

1.83%

54.7

10.94%

9.1

23.13%

4.3

2

2.07%

48.4

0.93%

107.0

3.00%

33.3

16.44%

6.1

35.53%

2.8

3

3.02%

33.1

1.15%

87.1

4.17%

24.0

20.65%

4.8

43.63%

2.3

4

3.52%

28.4

1.27%

78.7

4.79%

20.9

23.83%

4.2

48.26%

2.1

5

4.19%

23.9

1.37%

73.1

5.56%

18.0

26.75%

3.7

51.97%

1.9

40

1

1.90%

52.6

0.72%

138.0

2.63%

38.1

14.24%

7.0

27.54%

3.6

2

3.15%

31.8

1.03%

97.1

4.18%

23.9

20.06%

5.0

39.12%

2.6

3

4.45%

22.5

1.20%

83.2

5.65%

17.7

24.28%

4.1

45.68%

2.2

4

5.08%

19.7

1.29%

77.3

6.38%

15.7

27.32%

3.7

49.14%

2.0

5

5.91%

16.9

1.36%

73.5

7.27%

13.7

29.93%

3.3

51.73%

1.9

80

1

3.47%

28.8

0.91%

110.2

4.38%

22.8

19.37%

5.2

34.48%

2.9

2

5.40%

18.5

1.16%

86.3

6.56%

15.2

24.92%

4.0

44.04%

2.3

3

7.15%

14.0

1.27%

78.5

8.42%

11.9

28.48%

3.5

48.42%

2.1

4

7.88%

12.7

1.33%

75.3

9.21%

10.9

30.83%

3.2

50.48%

2.0

5

8.75%

11.4

1.36%

73.4

10.11%

9.9

32.55%

3.1

51.75%

1.9

120*

1

4.86%

20.6

0.97%

103.0

5.84%

17.1

21.92%

4.6

36.89%

2.7

2

7.10%

14.1

1.16%

86.3

8.25%

12.1

26.47%

3.8

44.03%

2.3

3

8.84%

11.3

1.23%

81.5

10.06%

9.9

29.03%

3.4

46.65%

2.1

4

9.42%

10.6

1.26%

79.7

10.67%

9.4

30.61%

3.3

47.71%

2.1

5

9.98%

10.0

1.26%

79.2

11.24%

8.9

31.49%

3.2

48.00%

2.1

150

1

5.83%

17.1

0.99%

101.2

6.82%

14.7

22.69%

4.4

37.53%

2.7

2

8.29%

12.1

1.14%

87.6

9.43%

10.6

26.61%

3.8

43.40%

2.3

3

10.08%

9.9

1.19%

84.0

11.27%

8.9

28.64%

3.5

45.25%

2.2

4

10.60%

9.4

1.21%

82.8

11.81%

8.5

29.81%

3.4

45.91%

2.2

5

11.03%

9.1

1.21%

82.9

12.23%

8.2

30.33%

3.3

45.84%

2.2

180

1

6.79%

14.7

1.00%

99.7

7.79%

12.8

24.12%

4.1

38.13%

2.6

2

9.37%

10.7

1.14%

88.1

10.50%

9.5

27.69%

3.6

43.14%

2.3

3

11.09%

9.0

1.17%

85.2

12.26%

8.2

29.48%

3.4

44.58%

2.2

4

11.50%

8.7

1.19%

84.4

12.69%

7.9

30.51%

3.3

45.04%

2.2

5

11.74%

8.5

1.18%

84.7

12.92%

7.7

30.90%

3.2

44.86%

2.2

  1. CRC colorectal cancer, AA advanced adenomas, high-risk and intermediate-risk adenomas combined, f-Hb faecal haemoglobin concentration, PPV positive predictive value, NNC number needed to colonoscopy.
  2. *Results for the current screening policy are in bold.