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Table 1 Variable completeness and univariable associations with colorectal cancer and polyps

From: The use of electronic healthcare records for colorectal cancer screening referral decisions and risk prediction model development

VariablePercentage with this variable recorded (N = 292,059)Prevalence of variable (%)Hazard Ratio (95% Confidence Interval)Standard ErrorP > z
Sociodemographic characteristics
 Sex100       
  Male (baseline) 46.74%(136,518/292,059)(---)
  Female 53.26%(155,541/292,059)0.655(0.609–0.706)0.0250.000*
 Age at Latest FOBT (continuous)100 Mean 66.43 (SD 4.47) 1.025(1.017–1.033)0.0040.000*
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 abnormal2.18(6362/292,059)2.18%(6362/292,059)55.936(51.988–60.183)2.0890.000*
 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)0.4730.000*
 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)0.0260.000*
 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)0.0320.000*
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)0.0010.000*
Smoking Status99.44(290,429/292,059)      
 Never-Smoked57.48(167,880/292,059)57.80%(167,880/290,429)    
 Ex-Smoker33.32(97,310/292,059)33.51%(97,310/290,429)1.532(1.417–1.656)0.0610.000*
 Current Smoker8.64(25,239/292,059)8.69%(25,239/290,429)1.619(1.437–1.824)0.0990.000*
Anthropometrics
 BMI (continuous)95.85(279,927/292,059)Mean 27.48 (SD 5.01) 1.029(1.022–1.036)0.0040.000*
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)2.8690.292
 Hb g/dL (continuous) within 365 days prior to the latest FOBT44.51(129,996/292,059)Mean 13.92 (SD 1.30) 0.990(0.953–1.029)0.0190.606
 Hb < 11 g/dL (reference category ≥11 g/dL) within 365 days prior to the latest FOBT44.51(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)0.3240.000*
 Mean Cell Volume fL (continuous) within 365 days prior to the latest FOBT44.33(129,481/292,059)Mean 91.11 (SD 5.08) 0.996(0.986–1.005)0.0050.382
 Mean Cell Volume < 80 fL (reference category ≥80 fL) within 365 days prior to the latest FOBT44.33(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)0.3260.000*
 Ferritin 15 μg/L (continuous) within 365 days prior to the latest FOBT8.59(25,082/292,059)Mean 127.07 (SD 201.66) 0.999(0.998–1.000)0.0000.069
 Ferritin < 15 μg/L (reference category ≥15 μg/L) within 365 days prior to the latest FOBT8.59(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)0.3770.000*
 Platelet Count ×  109/L (continuous) within 365 days prior to the latest FOBT44.40(129,685/292,059)Mean 245.61 (SD 66.00) 1.000(0.999–1.001)0.0000.691
 Platelet Count > 400 × 109/L (reference category ≤400 109/L) within 365 days prior to the latest FOBT44.40(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)0.1900.379
 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)0.0540.000*
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)0.2260.000*
 Diabetes (Recorded if observed)11.05% with 88.95% without(32,272/292,059) (259,787/292,059)1.470(1.329–1.627)0.0760.000*
 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)0.3460.911
 Ulcerative Colitis (Recorded if observed)0.61% with 99.39% without(1796/292,059) (290,263/292,059)1.686(1.177–2.416)0.3090.004*
 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)0.0690.030*
 Diverticulitis (Recorded if observed)6.37% with 93.63% without(18,606/292,059) (273,453/292,059)1.226(1.069–1.406)0.0860.004*
 Venous Thromboembolism (Recorded if observed)0.31% with 99.69% without(916/292,059) (291,143/292,059)1.421(0.824–2.451)0.3950.206
 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)0.1950.000*
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)0.2000.000*
 Diarrhoea (Recorded if observed)2.01% with, 97.99% without(5867/292,059) (286,192/292,059)1.779(1.464–2.161)0.1770.000*
 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)1.5100.096
 Flatulence (Recorded if observed)0.17% with 99.83% without(498/292,059) (291,561/292,059)2.481(1.439–4.278)0.6700.001*
 Tiredness (Recorded if observed)2.46% with 97.54% without(7173/292,059) (284,886/292,059)1.358(1.108–1.665)0.1410.003*
 Weight Loss (Recorded if observed)0.36% with 99.64% without(1057/292,059) (291,002/292,059)1.705(1.073–2.710)0.4030.024*
 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)0.4060.000*
 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)0.0890.000*
 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)0.1050.000*
 Abdominal Mass (Recorded if observed)0.06% with 99.94% without(165/292,059) (291,894/292,059)1.258(0.314–5.032)0.8900.746
 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)0.3490.000*
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)0.1270.000*
 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)0.2090.002*
 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)0.0840.000*
  1. * Significant at the p value of 0.05
  2. † Includes prescriptions of anti-spasmodic drug.
  3. 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