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Table 2 Test performance as measured by positive and negative predictive value (PPV, NPV), sensitivity, specificity, positive FITs per cancer detected, and cancer miss rate per 10,000 negative tests. FIT alone and threshold-based approach to FIT-blood test pairs

From: Combining faecal immunochemical testing with blood test results for colorectal cancer risk stratification: a consecutive cohort of 16,604 patients presenting to primary care

Test criteria PPV (95% CI) NPV (95% CI) Sensitivity (95% CI) Specificity (95% CI) Positive FITs to detect one cancer  Cancer miss rate per 10,000 negative tests
FIT alone
FIT≥2 µg Hb/g 4.7% (4.0, 5.5) 100.0% (99.9, 100) 96.4% (91.9, 98.5) 83.5% (82.9, 84.1) 21 4
FIT≥10 µg Hb/g 8.4% (7.1, 9.9) 99.9% (99.9, 100) 92.1% (86.4, 95.5) 91.5% (91.1, 91.9) 12 7
FIT-Blood Test Pairs
FIT≥2 µg Hb/g AND Low haemoglobina 5.1% (4.3, 6.2) 99.9% (99.8, 99.9) 89.1% (82.2, 93.5) 83.4% (82.7, 84.0) 17 44
High plateletsb 5.8% (4.6, 7.3) 99.6% (99.4, 99.7) 51.1% (42.9, 59.2) 93.0% (92.6, 93.4) 11 77
High white cellsc 8.7% (5.2, 14.4) 92.8% (91.5, 93.9) 9.4% (5.5, 15.3) 92.3% (91.0, 93.4) 29 80
Low mean cell haemoglobind 3.4% (1.7, 6.6) 99.2% (99.1, 99.3) 5.8% (2.9, 10.9) 98.6% (98.4, 98.8) 12 57
Low mean cell volumee 8.0% (6.1, 10.5) 99.4% (99.3, 99.5) 33.8% (26.5, 42.0) 96.7% (96.4, 97.0)   66
Any abnormal FBC 15.9% (11.4, 21.8) 99.3% (99.2, 99.4) 21.6% (15.6, 29.1) 99.0% (98.9, 99.2) 19 40
Low serum ferritinf 5.4% (4.3, 6.7) 99.6% (99.5, 99.7) 56.8% (48.5, 64.8) 91.6% (91.1, 92.0) 10 63
High serum ferriting 10.0% (7.3, 13.6) 99.4% (99.2, 99.5) 40.0% (30.5, 50.3) 96.3% (95.9, 96.7) 33 99
High C-reactive proteinh 3.0% (1.0, 8.5) 99.0% (98.8, 99.2) 3.3% (1.1, 9.3) 98.9% (98.7, 99.1) 18 59
FIT≥10 µg Hb/g AND Low haemoglobina 5.6% (4.0, 7.8) 99.4% (99.3, 99.5) 31.0% (22.8, 40.6) 95.7% (95.3, 96.0) 10 44
High plateletsb 10.3% (8.2, 12.8) 99.6% (99.4, 99.7) 49.6% (41.5, 57.8) 96.4% (96.1, 96.6) 8 77
High white cellsc 12.2% (7.1, 20.2) 99.2% (99.1, 99.4) 8.6% (5.0, 14.5) 99.5% (99.4, 99.6) 17 80
Low mean cell haemoglobind 5.8% (2.9, 10.9) 99.2% (99.1, 99.3) 5.8% (2.9, 10.9) 99.2% (99.1, 99.3) 7 58
Low mean cell volumee 13.5% (10.3, 17.6) 99.4% (99.3, 99.5) 32.4% (25.2, 40.5) 98.3% (98.0, 98.4) 4 67
Any abnormal FBC 23.3% (16.7, 31.7) 99.3% (99.2, 99.4) 20.1% (14.3, 27.6) 99.4% (99.3, 99.5) 10 39
Low serum ferritinf 9.6% (7.7, 11.8) 99.6% (99.5, 99.7) 55.4% (47.1, 63.4) 95.6% (95.3, 95.9) 6 62
High serum ferriting 17.0% (12.5, 22.6) 99.4% (99.2, 99.5) 40.0% (30.5, 50.3) 98.0% (97.7, 98.3) 15 98
High C-reactive proteinh 6.5% (2.2, 17.5) 99.0% (98.8, 99.2) 3.3% (1.1, 9.3) 99.5% (99.3, 99.6) 13 62
  1. Note: Serum ferritin and c-reactive protein tests were only conducted for a subset of patients (n = 8,923 and 12,202 respectively)
  2. CI Confidence interval
  3. a <130 g/L in men and <120 g/L in women
  4. b >400 μL/L
  5. c >11,000/mL
  6. d <27.4 pg/cell
  7. e <80 fL
  8. f <20 ng/mL
  9. g ≥350 ng/mL
  10. h >10 mg/L