Characteristics of participants taking benzodiazepines and those not taking benzodiazepines before and after propensity score matching
| Characteristic | No. of participants (before PS matching), n (%) | Standardized difference before PS matching, %* | No. of patients (after PS matching), n (%) | Standardized difference after PS matching, %* | ||
|---|---|---|---|---|---|---|
| No BZD use n = 40 775 | BZD use n = 5276 | No BZD use n = 5232 | BZD use n = 5232 | |||
| Sex | 1.2 | 1.6 | ||||
| Male | 15 271 (37.5) | 1945 (36.9) | 1889 (36.1) | 1928 (36.9) | ||
| Female | 25 504 (62.6) | 3331 (63.1) | 3343 (63.9) | 3304 (63.1) | ||
| Age, yr | ||||||
| < 65 | 1472 (3.6) | 248 (4.7) | 5.5 | 178 (3.4) | 217 (4.2) | 3.9 |
| 65–74 | 7807 (19.2) | 1066 (20.2) | 2.7 | 875 (16.7) | 904 (17.3) | 1.5 |
| 75–84 | 22 508 (55.2) | 2779 (52.7) | 5.1 | 2832 (54.1) | 2733 (52.2) | 3.8 |
| ≥ 85 | 8988 (22.0) | 1183 (22.4) | 0.9 | 1347 (25.8) | 1378 (26.3) | 1.3 |
| Socioeconomic position | ||||||
| High | 14 127 (34.7) | 1654 (31.4) | 7.0 | 1716 (32.8) | 1644 (31.4) | 3.0 |
| Medium | 23 698 (58.1) | 3138 (59.5) | 2.8 | 3030 (57.9) | 3109 (59.4) | 3.1 |
| Low | 2471 (6.1) | 417 (7.9) | 7.2 | 407 (7.8) | 413 (7.9) | 0.4 |
| Unknown | 479 (1.2) | 67 (1.3) | 0.9 | 79 (1.5) | 66 (1.3) | 2.1 |
| Drug use ever before index date | ||||||
| Antipsychotic | 3837 (9.4) | 1255 (23.8) | 39.4 | 2193 (41.9) | 1994 (38.1) | 7.8 |
| Benzodiazepine or Z-drug | 8136 (20.0) | 1649 (31.3) | 26.1 | 1809 (34.6) | 1615 (30.9) | 7.9 |
| Antidepressant | 10 341 (25.4) | 1855 (35.2) | 21.4 | 2316 (44.3) | 2176 (41.6) | 5.4 |
| Drug use at index date | ||||||
| Antineoplastic drug | 1363 (3.3) | 150 (2.8) | 2.9 | 171 (3.3) | 167 (3.2) | 0.4 |
| Opioid | 1100 (2.7) | 198 (3.8) | 6.0 | 295 (5.6) | 277 (5.3) | 1.5 |
| Antipsychotic | 2408 (5.9) | 1283 (24.3) | 53.2 | 2011 (38.4) | 2040 (39.0) | 1.1 |
| Antidepressant | 5462 (13.4) | 1195 (22.7) | 24.3 | 1553 (29.7) | 1493 (28.5) | 2.5 |
| Proton pump inhibitor | 3976 (9.8) | 666 (12.6) | 9.1 | 903 (17.3) | 857 (16.4) | 2.4 |
| Antiepileptic | 1405 (3.5) | 239 (4.5) | 5.5 | 310 (5.9) | 294 (5.6) | 1.3 |
| Cardiovascular drug | 29 903 (73.3) | 3841 (72.8) | 1.2 | 4045 (77.3) | 3935 (75.2) | 4.9 |
| Comorbidity | ||||||
| Cardiovascular disease | 19 633 (48.2) | 2567 (48.7) | 1.0 | 2694 (51.5) | 2567 (49.1) | 4.9 |
| Chronic heart failure | 11 332 (27.8) | 1452 (27.5) | 0.6 | 1586 (30.3) | 1518 (29.0) | 2.9 |
| Cardiac arrhythmia | 2748 (6.7) | 360 (6.8) | 0.3 | 362 (6.9) | 363 (6.9) | 0.1 |
| Hypertension | 12 005 (29.4) | 1574 (29.8) | 0.9 | 1680 (32.1) | 1632 (31.2) | 2.0 |
| Stroke | 3631 (8.9) | 489 (9.3) | 1.3 | 337 (6.4) | 104 (2.0) | 1.3 |
| Diabetes | 5430 (13.3) | 571 (10.8) | 7.7 | 641 (12.3) | 591 (11.3) | 3.0 |
| Complicated diabetes | 6631 (16.3) | 708 (13.4) | 8.0 | 778 (14.9) | 709 (13.6) | 0.0 |
| Peripheral vascular disease | 2005 (4.9) | 247 (4.7) | 1.1 | 258 (4.9) | 249 (4.8) | 0.8 |
| Substance abuse | 775 (1.9) | 190 (3.6) | 10.4 | 189 (3.6) | 203 (3.9) | 1.4 |
| Previous hospital-treated fracture | 7103 (17.4) | 951 (18.0) | 1.6 | 1085 (20.7) | 1067 (20.4) | 0.9 |
| Any tumour | 5178 (12.7) | 662 (12.6) | 0.5 | 668 (12.8) | 660 (12.6) | 0.5 |
| Anemia | 2695 (6.6) | 311 (5.9) | 3.0 | 345 (6.6) | 321 (6.1) | 1.9 |
| Fluid and electrolyte disorder | 1053 (2.6) | 188 (3.6) | 5.7 | 201 (3.8) | 197 (3.8) | 0.4 |
| Epilepsy | 808 (2.0) | 106 (2.0) | 0.2 | 135 (2.6) | 125 (2.4) | 1.2 |
| Respiratory comorbidity | ||||||
| Asthma/COPD | 3208 (7.9) | 425 (8.1) | 0.7 | 418 (8.0) | 424 (8.1) | 0.4 |
| Any pulmonary disease | 4302 (10.6) | 572 (10.8) | 0.9 | 591 (11.3) | 570 (10.9) | 1.3 |
| Previous pneumonia 1 yr before diagnosis of Alzheimer disease | 978 (2.4) | 105 (2.0) | 2.8 | 105 (2.0) | 104 (2.0) | 0.1 |
| Hospital admission for asthma/COPD before (≤ 1 yr) index date | 629 (1.5) | 102 (1.9) | 3.0 | 116 (2.2) | 114 (2.2) | 0.3 |
| Antibiotic or oral corticosteroid use before (≤ 30 d) index date | 4334 (10.6) | 624 (11.8) | 3.8 | 827 (15.8) | 760 (14.5) | 3.6 |
| Theophylline use before (≤ 180 d) index date | 331 (0.8) | 58 (1.1) | 3.0 | 50 (1.0) | 58 (1.1) | 1.5 |
| β-Agonist use before (≤ 180 d) index date | 1777 (4.4) | 230 (4.4) | 0.0 | 227 (4.3) | 225 (4.3) | 0.2 |
| Use of inhaled anticholinergic before (≤ 180 d) index date | 527 (1.3) | 78 (1.5) | 1.6 | 77 (1.5) | 83 (1.6) | 0.9 |
| Use of inhaled corticosteroid before (≤ 180 d) index date | 1395 (3.4) | 169 (3.2) | 1.2 | 170 (3.3) | 148 (2.8) | 2.5 |
| Combined inhaled corticosteroid/long-acting β-agonist use before (≤ 180 d) index date | 1457 (3.6) | 181 (3.4) | 0.8 | 180 (3.4) | 196 (3.8) | 1.6 |
| Mental health–related comorbidity | ||||||
| Schizophrenia | 447 (1.1) | 100 (1.9) | 6.6 | 103 (2.0) | 100 (1.9) | 0.4 |
| Depression or bipolar disorder | 806 (2.0) | 164 (3.1) | 7.2 | 194 (3.7) | 163 (3.1) | 3.3 |
| Psychosis | 2044 (5.0) | 510 (9.7) | 17.9 | 552 (10.6) | 513 (9.8) | 2.5 |
| Any admission to hospital for mental or behavioural disorders before (≤ 1 yr) index date | 1535 (3.8) | 330 (6.3) | 11.4 | 2452 (46.9) | 2380 (45.5) | 2.8 |
| Any psychiatric hospital admission before (≤ 1 yr) diagnosis of Alzheimer disease | 6985 (17.1) | 1456 (27.6) | 25.3 | 364 (7.0) | 327 (6.3) | 2.9 |
Note: BZD = benzodiazepine, COPD = chronic obstructive pulmonary disease, PS = propensity score, Z-drug = nonbenzodiazepine drug with similar activity to benzodiazepine.
↵* Values > 10% were considered to indicate meaningful imbalance between groups.