Table 1.
Selected baseline characteristics of study participants before and after high dimensional propensity score matching. Values are percentages unless stated otherwise
| Characteristics | Before propensity score matching | After propensity score matching | |||||
|---|---|---|---|---|---|---|---|
| Benzodiazepine initiators (n=1 686 410) | Benzodiazepine non-initiators (n=1 930 159) | Absolute standardized differences | Benzodiazepine initiators (n=1 252 988) | Benzodiazepine non-initiators (n=1 252 988) | Absolute standardized differences | ||
| Demographics: | |||||||
| Mean (SD) age (years) | 46.4 (13.8) | 43.6 (14.6) | 0.20 | 46.0 (13.8) | 45.2 (14.6) | 0.06 | |
| Men | 534 592 (35.1) | 770 133 (34.6) | 0.17 | 439 799 (35.1) | 433 534 (34.6) | 0.01 | |
| Comorbidities and life style factors: | |||||||
| Mean (SD) Charlson comorbidity score | 0.5 (1.2) | 0.4 (0.9) | 0.18 | 0.5 (1.1) | 0.4 (1.0) | 0.01 | |
| Smoking | 94 439 (5.6) | 71 416 (3.7) | 0.09 | 56 384 (4.5) | 56 384 (4.5) | 0.00 | |
| Obesity or overweight | 77 575 (4.6) | 75 276 (3.9) | 0.03 | 53 878 (4.3) | 52 625 (4.2) | 0.00 | |
| Hypertension | 468 822 (27.8) | 424 635 (22) | 0.13 | 320 765 (25.6) | 325 777 (26) | 0.01 | |
| Congestive heart failure | 28 669 (1.7) | 21 232 (1.1) | 0.05 | 17 542 (1.4) | 17 542 (1.4) | 0.00 | |
| Ischemic heart disease | 94 439 (5.6) | 75 276 (3.9) | 0.08 | 61 396 (4.9) | 62 649 (5) | 0.00 | |
| Cerebrovascular disease | 32 042 (1.9) | 21 232 (1.1) | 0.07 | 13 783 (1.1) | 13 783 (1.1) | 0.00 | |
| Other cardiovascular diseases | 102 871 (6.1) | 79 137 (4.1) | 0.09 | 63 902 (5.1) | 63 902 (5.1) | 0.00 | |
| Hyperlipidemia | 441 839 (26.2) | 426 565 (22.1) | 0.10 | 310 741 (24.8) | 315 753 (25.2) | 0.01 | |
| Diabetes | 163 582 (9.7) | 171 784 (8.9) | 0.03 | 120 287 (9.6) | 121 540 (9.7) | 0.00 | |
| Chronic obstructive pulmonary disease | 55 652 (3.3) | 36 673 (1.9) | 0.09 | 32 578 (2.6) | 31 325 (2.5) | 0.01 | |
| Asthma | 101 185 (6) | 84 927 (4.4) | 0.07 | 65 155 (5.2) | 65 155 (5.2) | 0.00 | |
| Pneumonia | 32 042 (1.9) | 25 092 (1.3) | 0.05 | 20 048 (1.6) | 20 048 (1.6) | 0.00 | |
| Osteoarthritis | 118 049 (7) | 94 578 (4.9) | 0.09 | 75 179 (6) | 76 432 (6.1) | 0.00 | |
| Other osteoarthritis and musculoskeletal disorders | 489 059 (29) | 440 076 (22.8) | 0.14 | 324 524 (25.9) | 324 524 (25.9) | 0.00 | |
| Neuropathic pain | 202 369 (12) | 142 832 (7.4) | 0.16 | 119 034 (9.5) | 119 034 (9.5) | 0.00 | |
| Back pain | 382 815 (22.7) | 285 664 (14.8) | 0.20 | 233 056 (18.6) | 233 056 (18.6) | 0.00 | |
| Fractures | 45 533 (2.7) | 46 324 (2.4) | 0.02 | 31 325 (2.5) | 30 072 (2.4) | 0.01 | |
| Falls | 13 491 (0.8) | 11 581 (0.6) | 0.02 | 8771 (0.7) | 8771 (0.7) | 0.00 | |
| Kidney disease | 57 338 (3.4) | 46 324 (2.4) | 0.06 | 36 337 (2.9) | 36 337 (2.9) | 0.00 | |
| Epilepsy or convulsions | 25 296 (1.5) | 15 441 (0.8) | 0.07 | 13 783 (1.1) | 12 530 (1) | 0.01 | |
| Cancer | 192 251 (11.4) | 146 692 (7.6) | 0.13 | 119 034 (9.5) | 120 287 (9.6) | 0.00 | |
| Anxiety | 241 157 (14.3) | 90 717 (4.7) | 0.33 | 98 986 (7.9) | 87 709 (7) | 0.03 | |
| Insomnia | 96 125 (5.7) | 40 533 (2.1) | 0.19 | 43 855 (3.5) | 38 843 (3.1) | 0.02 | |
| Other sleep disorders | 89 380 (5.3) | 65 625 (3.4) | 0.09 | 55 131 (4.4) | 52 625 (4.2) | 0.01 | |
| Depression | 274 885 (16.3) | 154 413 (8) | 0.26 | 1 44 094 (11.5) | 139 082 (11.1) | 0.01 | |
| Bipolar disorder | 38 787 (2.3) | 17 371 (0.9) | 0.11 | 17 542 (1.4) | 16 289 (1.3) | 0.01 | |
| Psychosis | 11 805 (0.7) | 5790 (0.3) | 0.06 | 5012 (0.4) | 5012 (0.4) | 0.00 | |
| Delirium | 11 805 (0.7) | 5790 (0.3) | 0.06 | 6265 (0.5) | 5012 (0.4) | 0.01 | |
| Drug or alcohol misuse | 37 101 (2.2) | 23 162 (1.2) | 0.08 | 20 048 (1.6) | 18 795 (1.5) | 0.01 | |
| Medications: | |||||||
| ACE inhibitors | 207 428 (12.3) | 218 108 (11.3) | 0.03 | 154 118 (12.3) | 156 624 (12.5) | 0.01 | |
| Angiotensin II receptor blockers | 134 913 (8) | 121 600 (6.3) | 0.07 | 95 227 (7.6) | 95 227 (7.6) | 0.00 | |
| β blockers | 237 784 (14.1) | 202 667 (10.5) | 0.11 | 162 888 (13) | 161 635 (12.9) | 0.00 | |
| Calcium channel blockers | 145 031 (8.6) | 202 667 (10.5) | 0.06 | 101 492 (8.1) | 105 251 (8.4) | 0.01 | |
| Thiazide diuretics | 82 634 (4.9) | 77 206 (4) | 0.04 | 57 637 (4.6) | 62 649 (5) | 0.02 | |
| Digoxin | 11 805 (0.7) | 9651 (0.5) | 0.03 | 7518 (0.6) | 7518 (0.6) | 0.00 | |
| Anticoagulants | 38 787 (2.3) | 34 743 (1.8) | 0.04 | 26 313 (2.1) | 26 313 (2.1) | 0.00 | |
| Antiplatelets | 38 787 (2.3) | 32 813 (1.7) | 0.04 | 26 313 (2.1) | 27 566 (2.2) | 0.01 | |
| Non-insulin glucose lowering agents | 119 735 (7.1) | 133 181 (6.9) | 0.01 | 88 962 (7.1) | 97 733 (7.8) | 0.03 | |
| Insulin | 35 415 (2.1) | 36 673 (1.9) | 0.01 | 25 060 (2) | 27 566 (2.2) | 0.01 | |
| Lipid lowering agents | 352 460 (20.9) | 351 289 (18.2) | 0.07 | 253 104 (20.2) | 261 874 (20.9) | 0.02 | |
| Oral corticosteroids | 227 665 (13.5) | 185 295 (9.6) | 0.12 | 142 841 (11.4) | 146 600 (11.7) | 0.01 | |
| NSAIDs | 298 495 (17.7) | 287 594 (14.9) | 0.08 | 199 225 (15.9) | 214 261 (17.1) | 0.03 | |
| Opioids | 590 244 (35) | 463 238 (24) | 0.24 | 377 149 (30.1) | 360 861 (28.8) | 0.03 | |
| Anticonvulsants | 148 404 (8.8) | 81 067 (4.2) | 0.19 | 76 432 (6.1) | 73 926 (5.9) | 0.01 | |
| SSRIs | 377 756 (22.4) | 223 898 (11.6) | 0.29 | 239 321 (19.1) | 189 201 (15.1) | 0.11 | |
| Other hypnotics | 195 624 (11.6) | 82 997 (4.3) | 0.27 | 100 239 (8) | 76 432 (6.1) | 0.07 | |
| Other anxiolytics | 37 101 (2.2) | 17 371 (0.9) | 0.11 | 20 048 (1.6) | 15 036 (1.2) | 0.03 | |
| Antipsychotics | 45 533 (2.7) | 21 232 (1.1) | 0.12 | 21 301 (1.7) | 20 048 (1.6) | 0.01 | |
| Barbiturates | 38 787 (2.3) | 21 232 (1.1) | 0.09 | 22 554 (1.8) | 17 542 (1.4) | 0.03 | |
| Indicators of healthcare utilization: | |||||||
| Any hospitalization | 175 387 (10.4) | 133 181 (6.9) | 0.12 | 101 492 (8.1) | 98 986 (7.9) | 0.01 | |
| Mean (SD) No of hospital days | 0.8 (4.2) | 0.5 (3.1) | 0.09 | 0.6 (3.4) | 0.6 (3.6) | 0.00 | |
| Mean (SD) No of physician visits | 4.0 (3.6) | 2.9 (2.9) | 0.31 | 3.4 (3.2) | 3.4 (3.1) | 0.00 | |
| Mean (SD) No of prescription drugs | 5.9 (4.0) | 4.3 (3.1) | 0.43 | 5.1 (3.6) | 5.1 (3.4) | 0.01 | |
| Psychiatric visit | 382 815 (22.7) | 210 387 (10.9) | 0.32 | 199 225 (15.9) | 182 936 (14.6) | 0.04 | |
ACE=angiotensin converting enzyme; NSAIDs=non-steroidal anti-inflammatory drugs; SSRIs=selective serotonin reuptake inhibitors.