Characteristics of participants taking Z-drugs and those not taking Z-drugs before and after propensity score matching
| Characteristic | No. of participants (before PS matching), n (%) | Standardized difference before PS matching, % | No. of participants (after PS matching), n (%) | Standardized difference after PS matching, %* | ||
|---|---|---|---|---|---|---|
| No Z-drug use n = 40 775 | Z-drug use n = 3312 | No Z-drug use n = 3269 | Z-drug use n = 3269 | |||
| Sex | 2.6 | 1.9 | ||||
| Male | 15 271 (37.5) | 1200 (36.2) | 1161 (35.5) | 1190 (36.4) | ||
| Female | 25 504 (62.6) | 2112 (63.8) | 2108 (64.5) | 2079 (63.6) | ||
| Age, yr | ||||||
| < 65 | 1472 (3.6) | 111 (3.4) | 1.4 | 96 (2.9) | 100 (3.1) | 0.7 |
| 65–74 | 7807 (19.2) | 644 (19.4) | 0.8 | 523 (16.0) | 546 (16.7) | 1.9 |
| 75–84 | 22 508 (55.2) | 1888 (57.0) | 3.6 | 1799 (55.0) | 1841 (56.3) | 2.6 |
| ≥ 85 | 8988 (22.0) | 669 (20.2) | 4.5 | 851 (26.0) | 782 (23.9) | 4.9 |
| Socioeconomic position | ||||||
| High | 14 127 (34.7) | 1156 (34.9) | 0.5 | 1160 (35.5) | 1140 (34.9) | 1.3 |
| Medium | 23 698 (58.1) | 1892 (57.1) | 2.0 | 1851 (56.6) | 1866 (57.1) | 0.9 |
| Low | 2471 (6.1) | 225 (6.8) | 3.0 | 219 (6.7) | 224 (6.9) | 0.6 |
| Unknown | 479 (1.2) | 39 (1.2) | 0.0 | 39 (1.2) | 39 (1.2) | 0.0 |
| Drug use ever before index date | ||||||
| Antipsychotic | 3837 (9.4) | 474 (14.3) | 15.2 | 699 (21.4) | 682 (20.9) | 1.3 |
| Benzodiazepine or Z-drug | 8136 (20.0) | 1235 (37.3) | 39.1 | 1227 (37.5) | 1196 (36.6) | 2.0 |
| Antidepressant | 10 341 (25.4) | 1155 (34.9) | 20.8 | 1356 (41.5) | 1271 (38.9) | 5.3 |
| Drug use at index date | ||||||
| Antineoplastic drug | 1363 (3.3) | 106 (3.2) | 0.8 | 128 (3.9) | 114 (3.5) | 2.3 |
| Opioid | 1100 (2.7) | 124 (3.7) | 5.9 | 192 (5.9) | 174 (5.3) | 2.4 |
| Antipsychotic | 2408 (5.9) | 393 (11.9) | 21.1 | 540 (16.5) | 560 (17.1) | 1.6 |
| Antidepressant | 5462 (13.4) | 645 (19.5) | 16.5 | 753 (23.0) | 747 (22.9) | 0.4 |
| Proton pump inhibitor | 3976 (9.8) | 459 (13.9) | 12.8 | 597 (18.3) | 572 (17.5) | 2.0 |
| Antiepileptic | 1405 (3.5) | 169 (5.1) | 8.2 | 198 (6.1) | 193 (5.9) | 0.6 |
| Cardiovascular drug | 29 903 (73.3) | 2528 (76.3) | 6.9 | 2564 (78.4) | 2559 (78.3) | 0.4 |
| Comorbidity | ||||||
| Cardiovascular disease | 19 633 (48.2) | 1652 (49.9) | 3.5 | 1622 (49.6) | 1633 (50.0) | 0.7 |
| Chronic heart failure | 11 332 (27.8) | 917 (27.7) | 0.2 | 941 (28.8) | 928 (28.4) | 0.9 |
| Cardiac arrhythmia | 2748 (6.7) | 256 (7.7) | 3.8 | 223 (6.8) | 254 (7.8) | 3.7 |
| Hypertension | 12 005 (29.4) | 1004 (30.3) | 1.9 | 1030 (31.5) | 1012 (31.0) | 1.2 |
| Stroke | 3631 (8.9) | 312 (9.4) | 1.8 | 226 (6.9) | 51 (1.6) | 2.4 |
| Diabetes | 5430 (13.3) | 403 (12.2) | 3.4 | 409 (12.5) | 423 (12.9) | 1.3 |
| Complicated diabetes | 6631 (16.3) | 529 (15.9) | 1.0 | 516 (15.8) | 524 (16.0) | 0.0 |
| Peripheral vascular disease | 2005 (4.9) | 185 (5.6) | 3.0 | 184 (5.6) | 183 (5.6) | 0.1 |
| Substance abuse | 775 (1.9) | 96 (2.9) | 6.5 | 103 (3.2) | 104 (3.2) | 0.2 |
| Previous hospital-treated fracture | 7103 (17.4) | 635 (19.2) | 4.5 | 670 (20.5) | 697 (21.3) | 2.0 |
| Any tumour | 5178 (12.7) | 461 (13.9) | 3.6 | 491 (15.0) | 461 (14.1) | 2.6 |
| Anemia | 2695 (6.6) | 246 (7.4) | 3.2 | 238 (7.3) | 252 (7.7) | 1.6 |
| Fluid and electrolyte disorders | 1053 (2.6) | 97 (2.9) | 2.1 | 102 (3.1) | 97 (3.0) | 0.9 |
| Epilepsy | 808 (2.0) | 61 (1.8) | 1.0 | 61 (1.9) | 65 (2.0) | 0.9 |
| Respiratory comorbidity | ||||||
| Asthma/COPD | 3208 (7.9) | 284 (8.6) | 2.6 | 278 (8.5) | 283 (8.7) | 0.6 |
| Any pulmonary disease | 4302 (10.6) | 355 (10.7) | 0.5 | 352 (10.8) | 357 (10.9) | 0.5 |
| Previous pneumonia 1 yr before diagnosis of Alzheimer disease | 978 (2.4) | 60 (1.8) | 4.1 | 52 (1.6) | 59 (1.8) | 1.7 |
| Admission to hospital for asthma/COPD before (≤ 1 yr) index date | 629 (1.5) | 67 (2.0) | 3.6 | 72 (2.2) | 69 (2.1) | 0.6 |
| Antibiotic or oral corticosteroid use before (≤ 30 d) index date | 4334 (10.6) | 383 (11.6) | 3.0 | 476 (14.6) | 467 (14.3) | 0.8 |
| Theophylline use before (≤ 180 d) index date | 331 (1.0) | 19 (0.6) | 2.9 | 16 (0.5) | 19 (0.6) | 1.3 |
| β-Agonist use before (≤ 180 d) index date | 1777 (4.4) | 175 (5.3) | 4.3 | 173 (5.3) | 176 (5.4) | 0.4 |
| Use of inhaled anticholinergic before (≤ 180 d) index date | 527 (1.3) | 41 (1.2) | 0.5 | 42 (1.3) | 44 (1.4) | 0.5 |
| Use of inhaled corticosteroid before (≤ 180 d) index date | 1395 (3.4) | 136 (4.1) | 3.6 | 119 (3.6) | 119 (3.6) | 0.0 |
| Combined inhaled corticosteroid/ long-acting β-agonist use before (≤ 180 d) index date | 1457 (3.6) | 126 (3.8) | 1.2 | 135 (4.1) | 134 (4.1) | 0.2 |
| Mental health–related comorbidity | ||||||
| Schizophrenia | 447 (1.1) | 39 (1.2) | 0.8 | 44 (1.4) | 39 (1.2) | 1.4 |
| Depression or bipolar disorder | 806 (2.0) | 100 (3.0) | 6.7 | 102 (3.1) | 100 (3.1) | 0.4 |
| Psychosis | 2044 (5.0) | 249 (7.5) | 10.4 | 249 (7.6) | 242 (7.4) | 0.8 |
| Any admission to hospital for mental or behavioural disorders before (≤ 1 yr) index date | 1535 (3.8) | 157 (4.7) | 4.8 | 956 (29.2) | 973 (29.8) | 1.1 |
| Any psychiatric hospital admission before (≤ 1 yr) diagnosis of Alzheimer disease | 6985 (17.1) | 645 (19.5) | 6.1 | 160 (4.9) | 154 (4.7) | 0.9 |
Note: COPD = chronic obstructive pulmonary disease, PS = propensity score, Z-drug = non-benzodiazepine drug with similar activity to benzodiazepine.
↵* Values > 10% were considered to indicate meaningful imbalance between groups.