Table 1.
Characteristics of gastric cancer cases and controls in the PCCIU database and UK Biobank.
| PCCIU | UK Biobank | |||
|---|---|---|---|---|
| Cases, n (%) | Controls, n (%) | Gastric cancer, n (%) | No gastric cancer, n (%) | |
| Count | 1119 (17.3) | 5394 (82.8) | 250 | 471,529 |
| Median exposure years (Min, Max) | 5.1 (2.0, 13.7) | 5.1 (2.0, 13.7) | ||
| Year of diagnosis | ||||
| 1996–1999 | 68 (6.1) | 332 (6.2) | ||
| 2000–2003 | 330 (29.5) | 1609 (29.8) | ||
| 2004–2007 | 494 (44.1) | 2359 (43.7) | 1 (0.4) | |
| 2008–2011 | 227 (20.3) | 1094 (20.3) | 99 (39.6) | |
| 2012–2015 | 150 (60.0) | |||
| Age at index/baselinea | ||||
| 0–59 | 165 (14.8) | 818 (15.2) | 70 (28.0) | 273,444 (58.0) |
| 60–69 | 292 (26.1) | 1450 (26.9) | 175 (70.0) | 195,959 (41.6) |
| 70+ | 662 (59.2) | 3126 (57.9) | 5 (2.0) | 2126 (0.5) |
| Male | 639 (57.1) | 3082 (57.1) | 182 (72.8) | 217,146 (46.1) |
| Deprivation | ||||
| 1 (least deprived) | 133 (11.9) | 635 (11.9) | 41 (16.4) | 94,422 (20.0) |
| 2 | 182 (16.3) | 866 (16.0) | 40 (16.0) | 94,009 (19.9) |
| 3 | 242 (21.6) | 1167 (21.6) | 49 (19.6) | 93,929 (19.9) |
| 4 | 284 (25.4) | 1378 (25.5) | 55 (22.0) | 94,383 (20.0) |
| 5 (most deprived) | 268 (23.9) | 1300 (24.1) | 64 (25.6) | 94,194 (20.0) |
| Missing | 10 (0.9) | 48 (0.9) | 1 (0.4) | 592 (0.1) |
| Smoking statusb | ||||
| Never | 387 (34.6) | 2052 (38.0) | 99 (39.6) | 257,994 (54.7) |
| Former | 320 (28.6) | 1414 (26.2) | 106 (42.4) | 160,790 (34.1) |
| Current | 249 (22.2) | 1009 (18.7) | 41 (16.4) | 50,005 (10.6) |
| Missing | 163 (14.6) | 919 (17.0) | 4 (1.6) | 2740 (0.6) |
| Selected comorbidities | ||||
| GORD | 16 (6.4) | 19,582 (4.2) | ||
| Peptic ulcer | 15 (1.3) | 75 (1.4) | 7 (2.8) | 5724 (1.2) |
| Diabetes | 54 (4.8) | 222 (4.1) | 22 (8.8) | 23,821 (5.1) |
| Oesophagitis | 7 (0.6) | 44 (0.8) | 4 (1.6) | 1361 (0.3) |
| Other drug use | ||||
| Statins | 265 (23.7) | 1248 (23.1) | 68 (27.2) | 76,473 (16.2) |
| Aspirin | 358 (32.0) | 1610 (29.9) | 72 (28.8) | 64,717 (13.7) |
| BMI | ||||
| Normal/underweight | 61 (24.4) | 154,912 (32.9) | ||
| Overweight | 119 (47.6) | 199,202 (42.2) | ||
| Obese | 164 (14.7) | 1060 (19.7) | 70 (28.0) | 114,501 (24.3) |
| Missing/not obese | 955 (85.3) | 4334 (80.4) | ||
| Missing | 0 | 2914 (0.6) | ||
| Alcohol consumption2 | ||||
| Never | 237 (21.2) | 969 (18.0) | 27 (10.8) | 37,865 (8.0) |
| <1 day per wk | 62 (24.8) | 106,482 (22.6) | ||
| 1–2 days per wk | 58 (23.2) | 121,461 (25.8) | ||
| 3–4 days per wk | 50 (20.0) | 108,892 (23.1) | ||
| >4 days per wk | 51 (20.4) | 95,401 (20.2) | ||
| Low | 529 (47.3) | 2660 (49.3) | ||
| High | 42 (3.7) | 184 (3.4) | ||
| Missing | 311 (27.8) | 1581 (29.3) | 2 (0.8) | 1428 (0.3) |
aAge at index date in the PCCIU database and age at baseline in the UK Biobank.
bSmoking status and alcohol consumption based on Read Codes in the PCCIU database and questionnaire in the UK Biobank.