Table 1.
Characteristics of 1,455 HC users participating in the Study of Environment, Lifestyle, and Fibroids (2010–2012, Detroit, MI area, USA)
| Ever used HCs* | |
|---|---|
| N=1,455 | |
| n (%) | |
| Age at enrollment (years) | |
| 23 – 26 | 421 (29) |
| 27 – 30 | 498 (34) |
| 31 – 35 | 536 (37) |
| Annual household income† | |
| < $20,000 | 643 (44) |
| $20,000 to $50,000 | 555 (38) |
| ≥ $50,000 | 248 (17) |
| Education‡ | |
| HS/GED or less | 300 (21) |
| Some college/associates/technical | 741 (51) |
| Bachelors/masters/PhD | 413 (28) |
| Body mass index (kg/m2) | |
| < 25 | 285 (20) |
| 25–29 | 318 (22) |
| 30–34 | 283 (19) |
| ≥ 35 | 569 (39) |
| Smoking history | |
| Never smoked | 1,077 (74) |
| Former smoker | 109 (7) |
| Current smoker (< 10 cigarettes per day) | 197 (14) |
| Current smoker (≥ 10 cigarettes per day) | 72 (5) |
| Age at menarche | |
| < 10 years | 271 (19) |
| 11 | 286 (20) |
| 12 | 390 (27) |
| 13 | 244 (17) |
| > 14 years | 264 (18) |
| Reproductive history | |
| Never pregnant | 327 (22) |
| Gravid, but nulliparous | 178 (12) |
| Parous | 950 (65) |
| 1 birth (percentage among parous) | 393 (41) |
| 2 births (percentage among parous) | 295 (31) |
| 3+ births (percentage among parous) | 262 (28) |
| Ever use of HCs by type | 1,455 (100) |
| Estrogen-containing | |
| Any route | 1,272 (87) |
| Combined oral contraceptives (COCs) | 1,185 (81) |
| Patch | 303 (21) |
| Ring | 227 (16) |
| Progestin-only contraceptives | |
| Any route | 864 (59) |
| Depo-Provera | 720 (49) |
| Hormonal intrauterine device (H-IUD) | 177 (12) |
| Implant | 42 (3) |
| Mini-pill | 77 (5) |
| Number of HC types* ever used | 1,455 (100) |
| 1 | 617 (42) |
| 2 | 510 (35) |
| 3 | 238 (16) |
| ≥ 4 | 90 (6) |
| Age at first use, Median [IQR]§ | 18 [16,20] |
HC use history at enrollment in SELF. Includes combined oral contraceptives (COCs), the patch, the ring, Depo-Provera, hormonal intrauterine devices (H-IUDs), the implant, and the mini-pill (progestin-only pill). Non-hormonal IUDs and emergency contraceptives are not included.
Annual household income was missing for n=12 participants.
Education was missing for n=1 participants.
Age at first use was missing for n=1 COC users, n=1 patch users, and n=1 shot users.
Abbreviations: HCs, hormonal contraceptives; HS, high school graduate; GED, general education development; PhD, doctor of philosophy; SELF, Study of Environment, Lifestyle, and Fibroids.