Table 1.
Variable completeness and univariable associations with colorectal cancer and polyps
| Variable | Percentage with this variable recorded (N = 292,059) | Prevalence of variable (%) | Hazard Ratio (95% Confidence Interval) | Standard Error | P > z | |||
|---|---|---|---|---|---|---|---|---|
| Sociodemographic characteristics | ||||||||
| Sex | 100 | |||||||
| Male (baseline) | – | 46.74% | (136,518/292,059) | – | (---) | – | – | |
| Female | – | 53.26% | (155,541/292,059) | 0.655 | (0.609–0.706) | 0.025 | 0.000* | |
| Age at Latest FOBT (continuous) | 100 | Mean 66.43 (SD 4.47) | 1.025 | (1.017–1.033) | 0.004 | 0.000* | ||
| BCSP Screening History (initially derived from BCSS) | ||||||||
| Latest FOBT Result (initially derived from BCSS) | 100 | (292,059/292,059) | ||||||
| BCSP FOB test normal (baseline) | 97.82 | (285,697/292,059) | 97.82% | (285,697/292,059) | – | (---) | – | – |
| BCSP FOB test abnormal | 2.18 | (6362/292,059) | 2.18% | (6362/292,059) | 55.936 | (51.988–60.183) | 2.089 | 0.000* |
| Previous Positive BCSP FOBTs (continuous) | (Recorded if observed) | 0 (99.47%) 1 (0.51%) 2 (0.02%) 3 (0.00068%) | (290,515/292,059) (1488/292,059) (54/292,059) (2/292,059) | 5.028 | (4.180–6.047) | 0.473 | 0.000* | |
| Previous Negative BCSP FOBTs (continuous) | (Recorded if observed) | 0 (60.44%) 1 (31.18%) 2 (8.03%) 3 (0.34%) 4 (0.0027%) | (176,523/292,059) (91,076/292,059) (23,465/292,059) (987/292,059) (8/292,059) | 0.769 | (0.720–0.821) | 0.026 | 0.000* | |
| Previously screened with a BCSP FOBT | (Recorded if observed) | 39.94% with 60.06% without | (116,641/292,059) (175,418/292,059) | 0.783 | (0.723–0.847) | 0.032 | 0.000* | |
| Lifestyle characteristics and measurements | ||||||||
| Alcohol (units per week) (continuous) | 78.00 | (227,792/292,059) | Mean 9.49 (SD 12.27) | 1.010 | (1.008–1.011) | 0.001 | 0.000* | |
| Smoking Status | 99.44 | (290,429/292,059) | ||||||
| Never-Smoked | 57.48 | (167,880/292,059) | 57.80% | (167,880/290,429) | ||||
| Ex-Smoker | 33.32 | (97,310/292,059) | 33.51% | (97,310/290,429) | 1.532 | (1.417–1.656) | 0.061 | 0.000* |
| Current Smoker | 8.64 | (25,239/292,059) | 8.69% | (25,239/290,429) | 1.619 | (1.437–1.824) | 0.099 | 0.000* |
| Anthropometrics | ||||||||
| BMI (continuous) | 95.85 | (279,927/292,059) | Mean 27.48 (SD 5.01) | 1.029 | (1.022–1.036) | 0.004 | 0.000* | |
| Laboratory test results | ||||||||
| Primary care FOBT | (Recorded if observed) | 0.01% with 99.99% without | (32/292,059) (292,027/292,059) | 2.868 | (0.404–20.369) | 2.869 | 0.292 | |
| Hb g/dL (continuous) within 365 days prior to the latest FOBT | 44.51 | (129,996/292,059) | Mean 13.92 (SD 1.30) | 0.990 | (0.953–1.029) | 0.019 | 0.606 | |
| Hb < 11 g/dL (reference category ≥11 g/dL) within 365 days prior to the latest FOBT | 44.51 | (129,996/292,059) | 1.50% < 11 g/dL 98.50% ≥11 g/dL | (1947/129,996) (128,049/129,996) | 2.231 | (1.679–2.966) | 0.324 | 0.000* |
| Mean Cell Volume fL (continuous) within 365 days prior to the latest FOBT | 44.33 | (129,481/292,059) | Mean 91.11 (SD 5.08) | 0.996 | (0.986–1.005) | 0.005 | 0.382 | |
| Mean Cell Volume < 80 fL (reference category ≥80 fL) within 365 days prior to the latest FOBT | 44.33 | (129,481/292,059) | 1.60% < 80 fL 98.40% ≥80 fL | (2073/129,481) (127,408/129,481) | 2.419 | (1.856–3.151) | 0.326 | 0.000* |
| Ferritin 15 μg/L (continuous) within 365 days prior to the latest FOBT | 8.59 | (25,082/292,059) | Mean 127.07 (SD 201.66) | 0.999 | (0.998–1.000) | 0.000 | 0.069 | |
| Ferritin < 15 μg/L (reference category ≥15 μg/L) within 365 days prior to the latest FOBT | 8.59 | (25,082/292,059) | 4.99% < 15 μg/L 95.01% ≥15 μg/L | (1252/25,082) (23,830/25,082) | 2.054 | (1.434–2.943) | 0.377 | 0.000* |
| Platelet Count × 109/L (continuous) within 365 days prior to the latest FOBT | 44.40 | (129,685/292,059) | Mean 245.61 (SD 66.00) | 1.000 | (0.999–1.001) | 0.000 | 0.691 | |
| Platelet Count > 400 × 109/L (reference category ≤400 109/L) within 365 days prior to the latest FOBT | 44.40 | (129,685/292,059) | 2.13% > 400 × 109/L) 97.87% ≤400 109/L | (2764/129,685) (126,921/129,685) | 1.155 | (0.837–1.594) | 0.190 | 0.379 |
| GP has ordered a blood test 365 days prior to their latest BCSP FOBT | (Recorded if observed) | 44.72% with 55.28% without | (130,611/292,059) (161,448/292,059) | 1.441 | (1.339–1.550) | 0.054 | 0.000* | |
| Other Conditions/Diagnoses | ||||||||
| Previous polyps diagnosed | (Recorded if observed) | 2.49% with 97.51% without | (7269/292,059) (284,790/292,059) | 3.181 | (2.767–3.658) | 0.226 | 0.000* | |
| Diabetes | (Recorded if observed) | 11.05% with 88.95% without | (32,272/292,059) (259,787/292,059) | 1.470 | (1.329–1.627) | 0.076 | 0.000* | |
| Crohn’s disease | (Recorded if observed) | 0.30% with 99.70% without | (884/292,059) (291,175/292,059) | 1.038 | (0.539–1.997) | 0.346 | 0.911 | |
| Ulcerative Colitis | (Recorded if observed) | 0.61% with 99.39% without | (1796/292,059) (290,263/292,059) | 1.686 | (1.177–2.416) | 0.309 | 0.004* | |
| Irritable Bowel Syndrome | (Recorded if observed) | 9.28% with 90.72% without | (27,103/292,059) (264,956/292,059) | 1.141 | (1.013–1.286) | 0.069 | 0.030* | |
| Diverticulitis | (Recorded if observed) | 6.37% with 93.63% without | (18,606/292,059) (273,453/292,059) | 1.226 | (1.069–1.406) | 0.086 | 0.004* | |
| Venous Thromboembolism | (Recorded if observed) | 0.31% with 99.69% without | (916/292,059) (291,143/292,059) | 1.421 | (0.824–2.451) | 0.395 | 0.206 | |
| Family History of Gastro-Intestinal Cancer | (Recorded if observed) | 1.51% with 98.49% without | (4423/292,059) (287,636/292,059) | 1.591 | (1.251, 2.023) | 0.195 | 0.000* | |
| GP recorded Symptoms | ||||||||
| Constipation | (Recorded if observed) | 1.46% with, 98.54% without | (4260/292,059) (287,799/292,059) | 1.654 | (1.305–2.097) | 0.200 | 0.000* | |
| Diarrhoea | (Recorded if observed) | 2.01% with, 97.99% without | (5867/292,059) (286,192/292,059) | 1.779 | (1.464–2.161) | 0.177 | 0.000* | |
| Loss of Appetite | (Recorded if observed) | 0.04% with, 99.96% without | (117/292,059) (291,942/292,059) | 2.614 | (0.843–8.109) | 1.510 | 0.096 | |
| Flatulence | (Recorded if observed) | 0.17% with 99.83% without | (498/292,059) (291,561/292,059) | 2.481 | (1.439–4.278) | 0.670 | 0.001* | |
| Tiredness | (Recorded if observed) | 2.46% with 97.54% without | (7173/292,059) (284,886/292,059) | 1.358 | (1.108–1.665) | 0.141 | 0.003* | |
| Weight Loss | (Recorded if observed) | 0.36% with 99.64% without | (1057/292,059) (291,002/292,059) | 1.705 | (1.073–2.710) | 0.403 | 0.024* | |
| Change in Bowel Habit | (Recorded if observed) | 0.57% with, 99.43% without | (1655/292,059) (290,404/292,059) | 2.610 | (1.924–3.539) | 0.406 | 0.000* | |
| Abdominal Pain† | (Recorded if observed) | 7.12% with, 92.88% without | (20,790/292,059) (271,269/292,059) | 1.425 | (1.261–1.610) | 0.089 | 0.000* | |
| Abdominal Pain | (Recorded if observed) | 4.86% with 95.14% without | (14,206/292,059) (277,853/292,059) | 1.424 | (1.232–1.646) | 0.105 | 0.000* | |
| Abdominal Mass | (Recorded if observed) | 0.06% with 99.94% without | (165/292,059) (291,894/292,059) | 1.258 | (0.314–5.032) | 0.890 | 0.746 | |
| Rectal Bleeding/melaena | (Recorded if observed) | 0.92% with 99.08% without | (2694/292,059) (289,365/292,059) | 3.118 | (2.504–3.884) | 0.349 | 0.000* | |
| Drug Prescriptions | ||||||||
| Antispasmodic drug prescription | (Recorded if observed) | 3.31% with 96.69% without | (9661/292,0590 (282,398/292,059) | 1.450 | (1.221–1.721) | 0.127 | 0.000* | |
| Anti-motility drug prescription | (Recorded if observed) | 1.24% with 98.76% without | (3613/292,0590 (288,446/292,059) | 1.535 | (1.176–2.005) | 0.209 | 0.002* | |
| Laxative Drug | (Recorded if observed) | 7.96% with 92.04% without | (23,234/292,059) (268,825/292,059) | 1.390 | (1.235–1.564) | 0.084 | 0.000* | |
* Significant at the p value of 0.05
† Includes prescriptions of anti-spasmodic drug.
FOBT Faecal Occult Blood Test, BCSP bowel cancer screening programme, BMI body mass index, MCV mean cell volume, IBS irritable bowel syndrome, Hb haemoglobin concentration