Table 1.
Baseline characteristics among non-BP and BP-users: before and after matching.
| before matching | after matching 1 to 1 | |||||
|---|---|---|---|---|---|---|
| Non-BP | BP-users | SMD | Non-BP | BP-users | SMD | |
| (n=6834) | (n=3105) | (n=3104) | (n=3104) | |||
| Age, mean (SD), years | 81.04 (10.15) | 79.93 (9.34) | 0.11 | 80.28 (10.78) | 79.94 (9.34) | 0.03 |
| Women | 4730 (69.2%) | 2552 (82.2%) | 0.31 | 2500 (80.5%) | 2551 (82.2%) | 0.04 |
| BMI, mean (SD), kg/m2 | 24.30 (4.68) | 24.50 (4.64) | 0.04 | 24.59 (4.81) | 24.50 (4.64) | 0.02 |
| Smoking | 0.07 | 0.02 | ||||
| Never | 4184 (61.2%) | 1864 (60.0%) | 1867 (60.1%) | 1864 (60.1%) | ||
| Former | 1531 (22.4%) | 783 (25.2%) | 795 (25.6%) | 782 (25.2%) | ||
| Current | 1119 (16.4%) | 458 (14.8%) | 442 (14.2%) | 458 (14.8%) | ||
| Drinking | 0.06 | 0.02 | ||||
| Never | 2073 (30.3%) | 912 (29.4%) | 922 (29.7%) | 912 (29.4%) | ||
| Former | 223 (3.3%) | 74 (2.4%) | 81 (2.6%) | 74 (2.4%) | ||
| Current | 4538 (66.4%) | 2119 (68.2%) | 2101 (67.7%) | 2118 (68.2%) | ||
| Index year | 0.53 | 0.06 | ||||
| 1999 | 733 (10.7%) | 153 (4.9%) | 138 (4.4%) | 153 (4.9%) | ||
| 2000 | 684 (10.0%) | 135 (4.3%) | 121 (3.9%) | 135 (4.3%) | ||
| 2001 | 646 (9.5%) | 149 (4.8%) | 156 (5.0%) | 149 (4.8%) | ||
| 2002 | 632 (9.2%) | 187 (6.0%) | 198 (6.4%) | 187 (6.0%) | ||
| 2003 | 626 (9.2%) | 205 (6.6%) | 218 (7.0%) | 205 (6.6%) | ||
| 2004 | 574 (8.4%) | 194 (6.2%) | 202 (6.5%) | 194 (6.2%) | ||
| 2005 | 460 (6.7%) | 259 (8.3%) | 268 (8.6%) | 259 (8.3%) | ||
| 2006 | 460 (6.7%) | 289 (9.3%) | 309 (10.0%) | 289 (9.3%) | ||
| 2007 | 435 (6.4%) | 286 (9.2%) | 288 (9.3%) | 286 (9.2%) | ||
| 2008 | 403 (5.9%) | 269 (8.7%) | 282 (9.1%) | 269 (8.7%) | ||
| 2009 | 347 (5.1%) | 287 (9.2%) | 272 (8.8%) | 287 (9.2%) | ||
| 2010 | 346 (5.1%) | 270 (8.7%) | 259 (8.3%) | 269 (8.7%) | ||
| 2011 | 302 (4.4%) | 272 (8.8%) | 250 (8.1%) | 272 (8.8%) | ||
| 2012 | 186 (2.7%) | 150 (4.8%) | 143 (4.6%) | 150 (4.8%) | ||
| Region | 0.09 | 0.02 | ||||
| North England | 3310 (48.4%) | 1469 (47.3%) | 1477 (47.6%) | 1468 (47.3%) | ||
| South England | 2413 (35.3%) | 1053 (33.9%) | 1055 (34.0%) | 1053 (33.9%) | ||
| Northern Ireland | 303 (4.4%) | 199 (6.4%) | 190 (6.1%) | 199 (6.4%) | ||
| Scotland | 334 (4.9%) | 157 (5.1%) | 148 (4.8%) | 157 (5.1%) | ||
| Wales | 474 (6.9%) | 227 (7.3%) | 234 (7.5%) | 227 (7.3%) | ||
| Drug confounders | ||||||
| Antiarrhythmics | 483 (7.1%) | 209 (6.7%) | 0.01 | 206 (6.6%) | 209 (6.7%) | <0.01 |
| Antidepressants | 2446 (35.8%) | 1139 (36.7%) | 0.02 | 1169 (37.7%) | 1139 (36.7%) | 0.02 |
| Antiepileptics | 429 (6.3%) | 212 (6.8%) | 0.02 | 220 (7.1%) | 212 (6.8%) | 0.01 |
| Antiparkinson | 366 (5.4%) | 118 (3.8%) | 0.07 | 124 (4.0%) | 118 (3.8%) | 0.01 |
| Anxiolytics | 1325 (19.4%) | 601 (19.4%) | <0.01 | 610 (19.7%) | 601 (19.4%) | 0.01 |
| PPI | 2207 (32.3%) | 1166 (37.6%) | 0.11 | 1176 (37.9%) | 1165 (37.5%) | 0.01 |
| NSAIDS | 5585 (81.7%) | 2671 (86.0%) | 0.12 | 2652 (85.4%) | 2671 (86.1%) | 0.02 |
| Systemic HRT | 374 (5.5%) | 344 (11.1%) | 0.21 | 285 (9.2%) | 344 (11.1%) | 0.06 |
| SERMS | 2 (0.0%) | 4 (0.1%) | 0.04 | 1 (0.0%) | 3 (0.1%) | 0.03 |
| Strontium | 10 (0.1%) | 2 (0.1%) | 0.03 | 3 (0.1%) | 2 (0.1%) | 0.01 |
| Calcium | 718 (10.5%) | 438 (14.1%) | 0.11 | 443 (14.3%) | 437 (14.1%) | 0.01 |
| Non-ocular corticoids | 440 (6.4%) | 265 (8.5%) | 0.08 | 245 (7.9%) | 265 (8.5%) | 0.02 |
| Ocular corticoids | 160 (2.3%) | 85 (2.7%) | 0.03 | 90 (2.9%) | 85 (2.7%) | 0.01 |
| Insulin | 100 (1.5%) | 28 (0.9%) | 0.05 | 33 (1.1%) | 28 (0.9%) | 0.02 |
| Co-morbidity confounders | ||||||
| Charlson Comorbidity in previous 5-years | 0.11 | 0.03 | ||||
| None | 3614 (52.9%) | 1808 (58.2%) | 1774 (57.2%) | 1807 (58.2%) | ||
| Mild (1 to 2) | 2160 (31.6%) | 884 (28.5%) | 899 (29.0%) | 884 (28.5%) | ||
| Moderate (3 to 4) | 707 (10.3%) | 272 (8.8%) | 275 (8.9%) | 272 (8.8%) | ||
| Severe (5+) | 353 (5.2%) | 141 (4.5%) | 156 (5.0%) | 141 (4.5%) | ||
| Asthma | 825 (12.1%) | 456 (14.7%) | 0.08 | 440 (14.2%) | 456 (14.7%) | 0.02 |
| Inflammatory bowel disease | 81 (1.2%) | 41 (1.3%) | 0.01 | 39 (1.3%) | 41 (1.3%) | 0.01 |
| Hypertension | 3075 (45.0%) | 1619 (52.1%) | 0.14 | 1619 (52.2%) | 1619 (52.2%) | <0.01 |
| Hyperlipidaemia | 762 (11.2%) | 527 (17.0%) | 0.17 | 503 (16.2%) | 527 (17.0%) | 0.02 |
| Ischemic heart disease | 1393 (20.4%) | 582 (18.7%) | 0.04 | 586 (18.9%) | 582 (18.8%) | <0.01 |
| CVD | 789 (11.5%) | 276 (8.9%) | 0.09 | 274 (8.8%) | 276 (8.9%) | <0.01 |
| COPD | 565 (8.3%) | 252 (8.1%) | 0.01 | 247 (8.0%) | 252 (8.1%) | 0.01 |
| Chronic renal failure | 294 (4.3%) | 131 (4.2%) | <0.01 | 148 (4.8%) | 131 (4.2%) | 0.03 |
| Cancers | 1324 (19.4%) | 534 (17.2%) | 0.06 | 579 (18.7%) | 534 (17.2%) | 0.04 |
| Cataract surgery | 903 (13.2%) | 307 (9.9%) | 0.10 | 322 (10.4%) | 307 (9.9%) | 0.02 |
| Type 1 diabetes | 34 (0.5%) | 17 (0.5%) | 0.01 | 17 (0.5%) | 17 (0.5%) | <0.01 |
| Type 2 diabetes | 739 (10.8%) | 329 (10.6%) | 0.01 | 321 (10.3%) | 329 (10.6%) | 0.01 |
Standardised mean difference, SMD; standard deviation, SD; body mass index, BMI; proton pump inhibitor, PPI; non-steroidal anti-inflammatory drug, NSAID; hormone replacement therapy, HRT; selective estrogen receptor modulator, SERM; cardio vascular disease, CVD; chronic obstructive pulmonary disease, COPD. SMD values <0.10 are indicators of good balance and suitability for survival analysis of the matched cohort.