Baseline characteristics of PPI and H2RA users before and after weighting
| Characteristic | Before weighting | After weighting* | ||||
| PPI | H2RA | ASD | PPI | H2RA | ASD | |
| Total | 973 281 | 198 306 | 973 281 | 972 083 | ||
| Age (mean, SD) | 60.4 (13.0) | 60.4 (13.1) | 0.00 | 60.4 (13.0) | 60.4 (28.9) | 0.00 |
| Male | 438 592 (45.1) | 85 505 (43.1) | 0.04 | 438 592 (45.1) | 436 521 (44.9) | 0.00 |
| Alcohol-related disorders | 55 957 (5.8) | 7912 (4.0) | 0.08 | 55 957 (5.8) | 56 352 (5.8) | 0.00 |
| Smoking status | ||||||
| Current | 260 166 (26.7) | 50 856 (25.7) | 0.03 | 260 166 (26.7) | 259 094 (26.7) | 0.00 |
| Former | 141 467 (14.5) | 20 490 (10.3) | 0.13 | 141 467 (14.5) | 142 286 (14.6) | 0.00 |
| Never | 538 106 (55.3) | 100 006 (50.4) | 0.10 | 538 106 (55.3) | 537 236 (55.3) | 0.00 |
| Missing | 33 542 (3.5) | 26 954 (13.6) | 0.37 | 33 542 (3.5) | 33 467 (3.4) | 0.00 |
| Body mass index | ||||||
| <25 kg/m2 | 361 873 (37.2) | 67 314 (33.9) | 0.07 | 361 873 (37.2) | 362 379 (37.3) | 0.00 |
| 25–29.9 kg/m2 | 326 240 (33.5) | 58 226 (29.4) | 0.09 | 326 240 (33.5) | 325 379 (33.5) | 0.00 |
| ≥30 kg/m2 | 177 306 (18.2) | 27 732 (14.0) | 0.12 | 177 306 (18.2) | 176 823 (18.2) | 0.00 |
| Missing | 107 862 (11.1) | 45 034 (22.7) | 0.31 | 107 862 (11.1) | 107 502 (11.1) | 0.00 |
| Atrial fibrillation | 34 778 (3.6) | 6037 (3.0) | 0.03 | 34 778 (3.6) | 35 576 (3.7) | 0.00 |
| Anaemia | 89 930 (9.2) | 14 860 (7.5) | 0.06 | 89 930 (9.2) | 90 836 (9.3) | 0.00 |
| Cancer | 81 000 (8.3) | 13 416 (6.8) | 0.06 | 81 000 (8.3) | 82 457 (8.5) | 0.01 |
| Congestive heart failure | 21 292 (2.2) | 6372 (3.2) | 0.06 | 21 292 (2.2) | 21 920 (2.3) | 0.00 |
| Gastric metaplasia | 293 (0.0) | 55 (0.0) | 0.00 | 293 (0.0) | 371 (0.0) | 0.00 |
| Hypercholesterolaemia | 293 279 (30.1) | 33 809 (17.1) | 0.31 | 293 279 (30.1) | 292 404 (30.1) | 0.00 |
| Hypertension | 311 466 (32.0) | 51 441 (25.9) | 0.14 | 311 466 (32.0) | 310 451 (31.9) | 0.00 |
| Venous thromboembolism | 44 121 (4.5) | 7944 (4.0) | 0.03 | 44 121 (4.5) | 44 645 (4.6) | 0.00 |
| Chronic kidney disease | 54 247 (5.6) | 4044 (2.0) | 0.19 | 54 247 (5.6) | 55 217 (5.7) | 0.00 |
| Stroke | 49 495 (5.1) | 10 105 (5.1) | 0.00 | 49 495 (5.1) | 50 673 (5.2) | 0.01 |
| Hernia | 32 113 (3.3) | 7586 (3.8) | 0.03 | 32 113 (3.3) | 33 737 (3.5) | 0.01 |
| Gastrointestinal bleeding | 85 760 (8.8) | 13 108 (6.6) | 0.08 | 85 760 (8.8) | 85 927 (8.8) | 0.00 |
| Dialysis | 794 (0.1) | 304 (0.2) | 0.02 | 794 (0.1) | 807 (0.1) | 0.00 |
| Gastric surgery | 2678 (0.3) | 645 (0.3) | 0.01 | 2678 (0.3) | 2854 (0.3) | 0.00 |
| Barrett’s oesophagus | 2928 (0.3) | 79 (0.0) | 0.06 | 2928 (0.3) | 3627 (0.4) | 0.01 |
| Helicobacter pylori infection | 20 440 (2.1) | 982 (0.5) | 0.14 | 20 440 (2.1) | 20 935 (2.2) | 0.00 |
| Gastro-oesophageal reflux disease | 86 985 (8.9) | 17 461 (8.8) | 0.00 | 86 985 (8.9) | 90 581 (9.3) | 0.01 |
| Peptic ulcer disease | 29 358 (3.0) | 8623 (4.4) | 0.07 | 29 358 (3.0) | 29 795 (3.1) | 0.00 |
| Dyspepsia | 169 147 (17.4) | 60 869 (30.7) | 0.32 | 169 147 (17.4) | 173 000 (17.8) | 0.01 |
| Gastritis | 41 343 (4.3) | 11 094 (5.6) | 0.06 | 41 343 (4.3) | 42 142 (4.3) | 0.00 |
| Stomach pain | 273 864 (28.1) | 58 350 (29.4) | 0.03 | 273 864 (28.1) | 277 733 (28.6) | 0.01 |
| Metformin | 56 972 (5.9) | 6286 (3.2) | 0.13 | 56 972 (5.9) | 57 053 (5.9) | 0.00 |
| Non-steroidal anti-inflammatory drugs | 692 208 (71.1) | 123 534 (62.3) | 0.19 | 692 208 (71.1) | 689 062 (70.9) | 0.01 |
| Antiplatelets | 231 359 (23.8) | 37 483 (18.9) | 0.12 | 231 359 (23.8) | 232 216 (23.9) | 0.00 |
| Dual antiplatelets | 67 206 (6.9) | 9164 (4.6) | 0.10 | 67 206 (6.9) | 68 440 (7.0) | 0.01 |
| Cyclooxygenase-2 inhibitors | 82 509 (8.5) | 8622 (4.4) | 0.17 | 82 509 (8.5) | 82 734 (8.5) | 0.00 |
| Prostaglandin analogues | 1564 (0.2) | 1101 (0.6) | 0.07 | 1564 (0.2) | 1692 (0.2) | 0.00 |
| Selective serotonin reuptake inhibitors | 216 197 (22.2) | 28 459 (14.4) | 0.20 | 216 197 (22.2) | 216 694 (22.3) | 0.00 |
| Anticoagulants | 37 461 (3.9) | 6718 (3.4) | 0.02 | 37 461 (3.9) | 38 322 (3.9) | 0.00 |
| Steroids | 155 048 (15.9) | 27 031 (13.6) | 0.06 | 155 048 (15.9) | 156 362 (16.1) | 0.00 |
| Year of cohort entry | ||||||
| 1990–1994 | 7839 (0.8) | 33 809 (17.1) | 0.59 | 7839 (0.8) | 7857 (0.8) | 0.00 |
| 1995–1999 | 36 611 (3.8) | 50 456 (25.4) | 0.65 | 36 611 (3.8) | 36 711 (3.8) | 0.00 |
| 2000–2004 | 148 408 (15.3) | 62 201 (31.4) | 0.39 | 148 408 (15.3) | 148 453 (15.3) | 0.00 |
| 2005–2009 | 327 938 (33.7) | 30 027 (15.1) | 0.44 | 327 938 (33.7) | 328 102 (33.8) | 0.00 |
| 2010–2018 | 452 485 (46.5) | 21 813 (11.0) | 0.85 | 452 485 (46.5) | 450 960 (46.4) | 0.00 |
Before weighting: counts (percentages), unless otherwise stated; after weighting: count, rounded to the nearest whole number, (percentages), unless otherwise stated.
*Pseudopopulation created by applying standardised mortality ratio weights from calendar time-specific propensity scores.
ASD, absolute standardised difference; H2RA, histamine-2 receptor antagonist; PPI, proton pump inhibitor.;