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Table 1 Distribution and accuracy of individual predictors for diagnosing SCD in primary care as observed in 810 Dutch patients with lower abdominal complaints referred for endoscopy in the CEDAR studya

From: Is there an added value of faecal calprotectin and haemoglobin in the diagnostic work-up for primary care patients suspected of significant colorectal disease? A cross-sectional diagnostic study

  Diagnostic accuracy for SCD   
  SCD (n = 141; 17.4 %) No SCD (n = 669; 82.6 %)   
Diagnostic predictorb Distribution in CEDAR study, %c Sensitivity, % (95 % CI) PPV, % (95 % CI) Specificity, % (95 % CI) NPV, % (95 % CI) AUC (95 % CI) Percent missing
Patient history
 Male sex 45.1 48.2 (40.1–56.4) 18.6 (15.0–22.9) 55.6 (51.8–59.3) 83.6 (79.9–86.7) 0.0
 Age in years, median (min–max) 61 (19–92) 0.602 (0.553–0.652) 0.0
 Absence of abdominal pain 19.3 33.0 (25.7–41.1) 29.7 (23.1–37.3) 83.5 (80.5–86.1) 85.5 (82.6–88.0) 0.4
 Duration of abdominal pain in weeks, median (min–max) 90 (0–10 years)d 0.597 (0.543–0.652)e 7.4
 Rectal blood loss 43.6 66.0 (57.8–73.3) 26.3 (22.0–31.1) 61.1 (57.3–64.7) 89.5 (86.3–92.0) 0.6
 Rectal mucus 38.0 51.3 (43.1–59.5) 23.5 (19.1–28.6) 64.9 (61.2–68.4) 86.3 (83.1–89.1) 1.2
 Weight loss 19.2 23.8 (17.4–31.5) 21.6 (15.8–28.7) 81.8 (78.7–84.6) 83.6 (80.5–86.2) 0.7
 Change in bowel habit 65.5 68.0 (58.6–76.4) 18.1 (14.9–21.7) 35.1 (31.4–38.9) 83.9 (78.8–88.1) 12.3
 Absence of abdominal bloating 45.0 60.5 (52.1–68.4) 23.4 (19.3–28.1) 58.3 (54.5–62.1) 87.5 (84.1–90.3) 4.2
 Absence of fever 89.0 89.2 (83.0–93.4) 17.4 (14.8–20.4) 11.0 (8.9–13.6) 82.9 (73.7–89.4) 0.6
 Absence of constipation 42.1 50.0 (41.8–58.2) 20.7 (16.7–25.3) 59.6 (55.7–63.3) 85.0 (81.4–87.9) 3.5
 Diarrhoea 29.1 29.4 (22.4–37.4) 17.6 (13.2–23.0) 71.0 (67.4–74.3) 82.7 (79.3–85.5) 1.6
 Absence of family history of CRC 81.7 84.3 (76.0–90.6) 17.9 (15.1–21.1) 18.8 (15.7–22.3) 85.0 (77.6–90.7) 14.2
Physical examination
 Absence of palpable abdominal mass 95.2 95.6 (89.5–99.3) 17.5 (14.9–20.4) 4.9 (3.4–6.9) 84.4 (67.3–95.3) 14.8
 Abnormal digital rectal examination 7.8 11.5 (6.6–18.5) 25.7 (14.5–39.7) 92.9 (89.8–95.5) 83.3 (80.4–85.8) 17.7
Blood analyses        
 Hb in g/dL, mean (SD) 14.2 (1.3) 0.556 (0.502–0.610)f 4.4
 Anaemia (♀ < 12 and ♂ < 13 g/dL) 5.5 9.9 (5.8–16.0) 31.0 (18.9–46.1) 95.4 (93.4–96.8) 83.4 (80.6–85.9) 4.4
 CRP in mg/L, median (min–max) 2 (0–20)d 0.587 (0.535–0.638) 4.6
 Elevated CRP (≥10 mg/L) 9.4 12.2 (7.5–18.9) 22.7 (14.5–33.5) 91.2 (88.8–93.2) 83.1 (80.2–85.7) 4.6
Faecal tests
 Calprotectin POC test in μg/g, median (min–max) 48 (30–300) 0.681 (0.629–0.732) 5.6
 Positive calprotectin POC test (>50 μg/gg) 48.7 69.6 (61.4–76.7) 24.9 (20.8–29.4) 55.7 (51.8–59.5) 89.7 (86.4–92.3) 5.6
 Calprotectin ELISA test in μg/g, median (min–max) 62 (8–500)d 0.661 (0.606–0.716) 8.6
 Positive calprotectin ELISA test (>50 μg/gg) 56.6 71.4 (63.2–78.5) 21.9 (18.4–26.0) 46.5 (42.6–50.4) 88.5 (84.7–91.5) 8.6
 Positive POC FIT (>6 μg Hb/gh) 25.1 67.2 (58.9–74.5) 46.5 (39.6–53.7) 83.7 (80.5–86.6) 92.4 (89.9–94.3) 6.2
  1. AUC area under the receiver operating characteristic curve; CEDAR Cost-Effectiveness of a Decision rule for Abdominal complaints in primary caRe; CI confidence interval; CRC colorectal cancer; CRP C-reactive protein; ELISA enzyme-linked immunosorbent assay; FIT faecal immunochemical test for haemoglobin; Hb haemoglobin; NPV negative predictive value; POC point-of-care; PPV positive predictive value; SCD significant colorectal disease; SD standard deviation
  2. aDistribution and accuracy estimates per diagnostic predictor are following multiple imputation of missing values
  3. bPredictors are coded such that the reported category indicates a higher risk of SCD, to allow direct comparison of accuracy measures across predictors
  4. cIf not otherwise stated
  5. dOutliers were truncated
  6. eNegative relation with presence of SCD
  7. fU-shape relation with presence of SCD
  8. gManufacturer’s threshold
  9. hLower detection limit as stated by manufacturer