Clinical features in cases and controls in the whole study population and association with CRC and/or IBD
| Clinical feature | Frequency of features in cases and controls in CRC/IBD dataset | OR (95% CI) in multivariable analysis for: | |||||
|---|---|---|---|---|---|---|---|
| Cases, n (%) n= 11 239 | Controls, n (%) n= 26 926 | Positive LR PPVa (95% CI) | (95% CI) | CRC/IBD | IBD | CRC | |
| Symptoms | |||||||
| Diarrhoea | 3047 (27.1) | 531 (2) | 13.8 (12.6 to 15) | 0.5 (0.5 to 0.6) | 8.9 (7.5 to 11) | 9.5 (7.9 to 12) | 7.7 (4.3 to 14) |
| Abdominal pain | 3040 (27.1) | 1534 (5.7) | 4.8 (4.5 to 5) | 0.2 (0.2 to 0.2) | 3.9 (3.4 to 4.5) | 3.5 (3.0 to 4.1) | 6.0 (4.2 to 8.7) |
| Rectal bleeding | 2654 (23.6) | 201 (0.8) | 31.6 (27.5 to 36.5) | 1.2 (1.1 to 1.4) | 42 (33 to 55) | 40 (31 to 53) | 54 (26 to 110) |
| Change in bowel habit | 730 (6.5) | 65 (0.2) | 26.9 (20.9 to 34.6) | 1.0 (0.8 to 1.3) | 27 (19 to 38) | 22 (15 to 33) | 58 (21 to 160) |
| Constipation | 471 (4.2) | 245 (0.9) | a | a | a | a | 7.9 (4.3 to 14) |
| Nausea/vomiting | 540 (4.8) | 410 (1.5) | a | a | a | a | 2.7 (1.4 to 5.1) |
| Rectal mass | 189 (1.7) | 9 (0.03) | a | a | a | a | 190 (51 to 720) |
| Investigations | |||||||
| Raised inflammatory markers | 3115 (27.7) | 575 (2.1) | 13 (11.9 to 14.2) | 0.5 (0.5 to 0.6) | 5.4 (4.6 to 6.3) | 6.1 (5.1 to 7.3) | 3.1 (2.0 to 4.7) |
| Low haemoglobin | 1802 (16) | 572 (2.1) | 7.6 (6.9 to 8.3) | 0.3 (0.3 to 0.3) | 2.5 (2.1 to 3.1) | 2.2 (1.8 to 2.8) | 5.2 (3.2 to 8.5) |
| Raised platelets | 1678 (14.9) | 206 (0.8) | 19.5 (16.9 to 22.5) | 0.8 (0.7 to 0.9) | 4.4 (3.4 to 5.7) | 5.4 (4.0 to 7.2) | a |
| Raised white cell count | 1472 (13.1) | 488 (1.8) | 7.2 (6.5 to 8) | 0.3 (0.3 to 0.3) | 1.5 (1.3 to 1.9) | 1.7 (1.4 to 2.1) | a |
| Abnormal liver function | 1392 (12.4) | 1019 (3.8) | 3.3 (3 to 3.5) | 0.1 (0.1 to 0.1) | 1.4 (1.2 to 1.6) | 1.4 (1.2 to 1.7) | a |
| Low mean red cell volume | 1102 (9.8) | 290 (1.1) | 9.1 (8 to 10.3) | 0.4 (0.3 to 0.4) | 2.7 (2.1 to 3.5) | 2.4 (1.8 to 3.2) | 4.3 (2.3 to 8.0) |
↵a Features that did not retain independent significance in multivariable analysis in the CRC/IBD population. All associations in the above table had a P-value of <0.001. CRC = colorectal cancer. IBD = inflammatory bowel disease. LR = likelihood ratio. PPV = positive predictive value.