Table 1.
Characteristics of participants, overall and according to NSAID exposure at the end of follow-up (E3N cohort, 2004–2014)
| Characteristics at the end of follow-up1 | All women (n = 62,512) | NSAID exposure at the end of follow-up | |
|---|---|---|---|
| Never/occasional users (n = 24,019) | Recurrent users (n = 38,493) | ||
| Sociodemographic factors | |||
| Age (years), mean (SD) | 72.1 (6.7) | 71.8 (6.7) | 72.2 (6.2) |
| Educational level, N (%) | |||
| < High school | 6516 (10) | 2160 (9) | 4356 (11) |
| From high school to 4 years higher education | 45,138 (72) | 17,450 (73) | 27,688 (72) |
| At least 5 years higher education | 10,858 (18) | 4409 (18) | 6449 (17) |
| Lifestyle factors, N (%) | |||
| BMI (kg/m2) | |||
| < 18.5 | 2626 (4) | 1284 (5) | 1342 (3) |
| [18.5–23[ | 25,409 (41) | 10,913 (45) | 14,496 (38) |
| [23–25[ | 13,197 (21) | 5020 (21) | 8177 (21) |
| [25–30[ | 16,139 (26) | 5359 (22) | 10,780 (28) |
| ≥ 30 | 5141 (8) | 1443 (6) | 3698 (10) |
| Physical activity (Met-h/week) | |||
| ≤ 34.8 | 15,649 (25) | 5863 (24) | 9786 (25) |
| ]34.8–57.6] | 15,680 (25) | 5986 (25) | 9694 (25) |
| ]57.6–88.8] | 15,567 (25) | 6085 (25) | 9482 (25) |
| > 88.8 | 15,616 (25) | 6085 (25) | 9531 (25) |
| Smoking status | |||
| Never smoker | 33,281 (53) | 13,258 (55) | 20,023 (52) |
| Current smoker | 4741 (8) | 1681 (7) | 3060 (8) |
| Past smoker | 24,490 (39) | 9080 (38) | 15,410 (40) |
| Alcohol intake (g/day) | |||
| Abstainer | 7832 (13) | 3283 (14) | 4549 (12) |
| ≤ 5 | 16,796 (27) | 6611 (28) | 10,185 (26) |
| ]5–10] | 9357 (15) | 3752 (16) | 5605 (15) |
| ]10–20] | 12,053 (19) | 4546 (19) | 7507 (20) |
| > 20 | 12,522 (20) | 4483 (19) | 8039 (21) |
| Missing | 3952 (6) | 1344 (6) | 2608 (7) |
| Reproductive factors | |||
| Breastfeeding, N (%) | |||
| Never | 23,425 (37) | 9088 (38) | 14,337 (37) |
| Ever | 34,174 (55) | 13,248 (55) | 20,926 (54) |
| Missing | 4913 (8) | 1683 (7) | 3230 (9) |
| Age at menopause (years), mean (SD) | 50.52 (3.73) | 50.68 (3.68) | 50.41 (3.76) |
| Age at menarche (years), N (%) | |||
| < 13 | 28,078 (45) | 10,413 (43) | 17,665 (46) |
| ≥ 13 | 34,434 (55) | 13,606 (57) | 20,828 (54) |
| Parity and age at first full-term pregnancy, N (%) | |||
| Nulliparous | 7282 (12) | 3010 (13) | 4272 (11) |
| First child before age 30 years, one or two children | 31,393 (50) | 11,739 (49) | 19,654 (51) |
| First child before age 30 years, three or more children | 17,373 (28) | 6602 (27) | 10,771 (28) |
| First child after age 30 years | 6464 (10) | 2668 (11) | 3796 (10) |
| Ever use of oral contraceptives, N (%) | 38,570 (62) | 14,191 (59) | 24,379 (63) |
| Lifetime MHT use, N (%) | |||
| Never | 17,273 (28) | 8076 (34) | 9197 (24) |
| Recent | 5300 (8) | 1866 (8) | 3434 (9) |
| Past | 39,939 (64) | 14,077 (59) | 25,862 (67) |
| Medical events and medical follow-up, N (%) | |||
| Number of medical consultations/visits during the preceding 6 months | |||
| 0 | 3277 (5) | 1928 (8) | 1349 (4) |
| [1–4[ | 25,413 (41) | 11,387 (47) | 14,026 (36) |
| ≥ 4 | 33,491 (54) | 10,434 (43) | 23,057 (60) |
| Missing | 331 (1) | 270 (1) | 61 (0) |
| Self-report of a mammogram performed during the previous follow-up cycle | 51,097 (82) | 19,194 (80) | 31,903 (83) |
| Personal history of benign breast disease | 23,268 (37) | 8483 (35) | 14,785 (38) |
| History of breast cancer in first-degree relatives | 7139 (11) | 2735 (11) | 4404 (11) |
| Recurrent use2 of other drugs, N (%) | |||
| Systemic glucocorticoids | 17,391 (28) | 3551 (15) | 13,840 (36) |
| Paracetamol | 38,392 (61) | 10,527 (44) | 27,865 (72) |
| Proton pump inhibitors | 30,063 (48) | 6308 (26) | 23,755 (62) |
| Anti-arthritics | 26,400 (42) | 6471 (27) | 19,929 (52) |
| Comorbidities, N (%) | |||
| History of arthrosis | 21,475 (34) | 5568 (23) | 15,907 (41) |
| History of rheumatism | 6111 (10) | 2400 (10) | 3711 (10) |
| History of arthritis | 888 (1) | 248 (1) | 640 (2) |
| History of polyarthritis | 2375 (4) | 451 (2) | 1924 (5) |
| History of spondyloarthritis | 236 (1) | 29 (1) | 207 (1) |
| History of migraine | 21,591 (35) | 7073 (29) | 14,518 (38) |
Abbreviations: BMI body mass index, MET-h metabolic equivalent task-hour, MHT menopausal hormone therapy, NSAID nonsteroidal anti-inflammatory drug, SD standard deviation
1Except for years of schooling, physical activity level, age at menarche, parity and age at first birth, lifetime use of oral contraceptives, history of breast cancer in first-degree relatives, and age at menopause, which were assessed before the start of follow-up
2At least two reimbursements during any previous 3-month period since January 1, 2004