Table 1.
Characteristics of study population. Values are numbers (percentages)* unless stated otherwise
| Exposure | Person years | Age† ‡ | University education | BMI† | Smoking‡ | Comorbidities§ | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hypertension | Diabetes | Polycystic ovary syndrome | Endometriosis | Migraine | Systemic connective tissue disorders | Inflammatory polyarthropathies | ||||||
| Non-use of hormonal contraception and NSAIDs | 13 632 179 | 34 (24-42) | 2 554 784 (18.7) | 23 (20-26) | 500 787 (19.1) | 53 257 (0.4) | 152 011 (1.1) | 35 265 (0.3) | 78 225 (0.6) | 819 696 (6.0) | 71 747 (0.5) | 200 725 (1.5) |
| Hormonal contraception use only | ||||||||||||
| High risk hormonal contraception | 4 298 461 | 24 (20-32) | 595 293 (13.8) | 23 (21-26) | 152 054 (22.9) | 8528 (0.2) | 34 561 (0.8) | 12 332 (0.3) | 24 011 (0.6) | 287 818 (6.7) | 25 114 (0.6) | 54 191 (1.3) |
| Medium risk hormonal contraception | 1 852 352 | 25 (20-33) | 253 149 (13.7) | 23 (21-27) | 67 408 (23.0) | 4171 (0.2) | 15 845 (0.9) | 5130 (0.3) | 9240 (0.5) | 118 720 (6.4) | 11 868 (0.6) | 24 702 (1.3) |
| Low/no risk hormonal contraception | 1 116 421 | 37 (31-43) | 359 413 (32.2) | 23 (21-26) | 95 609 (15.5) | 7543 (0.8) | 20 032 (1.8) | 4627 (0.4) | 18 060 (1.6) | 164 257 (14.7) | 11 323 (1.0) | 23 269 (2.1) |
| NSAID use only | ||||||||||||
| Any | 51 864 | 39 (32-45) | 8975 (17.3) | 24 (21-29) | 3208 (27.5) | 505 (1.0) | 1509 (2.9) | 256 (0.5) | 684 (1.3) | 8928 (17.2) | 917 (1.8) | 3012 (5.8) |
| Ibuprofen | 28 586 | 39 (31-45) | 4908 (17.2) | 24 (21-29) | 2205 (28.1) | 270 (0.9) | 890 (3.1) | 168 (0.6) | 346 (1.2) | 4370 (15.3) | 457 (1.6) | 1380 (4.8) |
| Diclofenac | 11 162 | 39 (32-45) | 1984 (17.8) | 24 (21-29) | 574 (26.9) | 105 (0.9) | 292 (2.6) | 44 (0.4) | 154 (1.4) | 2056 (18.4) | 180 (1.6) | 623 (5.6) |
| Naproxen | 3426 | 36 (25-43) | 538 (15.7) | 24 (21-28) | 115 (24.7) | 30 (0.9) | 79 (2.3) | 13 (0.4) | 56 (1.6) | 467 (13.6) | 44 (1.3) | 183 (5.3) |
| Concomitant use of hormonal contraception and NSAIDs | ||||||||||||
| High risk hormonal contraception and any NSAID | 20 036 | 28 (22-36) | 2323 (11.6) | 24 (21-28) | 1261 (30.9) | 103 (0.5) | 303 (1.5) | 84 (0.4) | 278 (1.4) | 3390 (16.9) | 340 (1.7) | 795 (4.0) |
| Medium risk hormonal contraception and any NSAID | 8073 | 30 (23-38) | 935 (11.6) | 24 (21-29) | 553 (31.8) | 46 (0.6) | 136 (1.7) | 32 (0.4) | 97 (1.2) | 1317 (16.3) | 134 (1.7) | 333 (4.1) |
| Low/no risk hormonal contraception and any NSAID | 6497 | 39 (33-44) | 1500 (23.1) | 24 (21-28) | 732 (22.5) | 81 (1.3) | 221 (3.4) | 42 (0.6) | 181 (2.9) | 1757 (27.0) | 162 (2.5) | 330 (5.1) |
BMI=body mass index; NSAID=non-steroidal anti-inflammatory drug.
Descriptive percentages are percentages of person time with given characteristic.
Weighted median (interquartile range). Weight calculated as person time with given characteristic divided by total amount of person time during which specific exposure was used.
Information on smoking and BMI was available for parous women only. Information on smoking status was available from 1991 for 500 547 women for 4.2 million person years. Information on body mass index was available from 2004 for 357 503 women for 2.2 million person years.
Person years (percentage of total number of person years in exposure category).