Crude odds ratios and 95% confidence intervals for short and long menstrual cycles in female workers according to work areas, potentially exposed chemical agents, and demographic and lifestyle characteristics
| Risk factors | Number of workers | Crude OR (95% CI) for short menstrual cycles | Crude OR (95% CI) for long menstrual cycles | ||
|---|---|---|---|---|---|
| Short range | Normal range | Long range | |||
| <24 days | 24–35 days | >35 days | |||
| As, arsenic compounds; EGEs, ethylene glycol ethers; fab, fabrication; HF, hydrofluoric acid; IPA, isopropyl alcohol; non-fab, non-fabrication; P, phosphorous compounds. | |||||
| Non-fab | 6 | 112 | 15 | 1 | 1 |
| Fab | 30 | 359 | 84 | 1.6 (0.6 to 3.8) | 1.8 (1.0 to 3.1) |
| Etching | 11 | 135 | 17 | 1.5 (0.6 to 4.2) | 0.9 (0.5 to 2.0) |
| Thin film | 7 | 98 | 22 | 1.3 (0.4 to 4.1) | 1.7 (0.8 to 3.4) |
| As+HF | – | 3 | 1 | – | – |
| As+HF+P | 7 | 93 | 21 | 1.4 (0.5 to 4.3) | 1.7 (0.8 to 3.5) |
| As+HF+IPA+P | – | 2 | – | – | – |
| Photolithography | 6 | 48 | 20 | 2.3 (0.7 to 7.6) | 3.1 (1.5 to 6.6) |
| EGEs | 2 | 5 | 1 | – | – |
| EGEs+IPA | 4 | 43 | 19 | 1.7 (0.5 to 6.5) | 3.3 (1.5 to 7.1) |
| Diffusion | 6 | 78 | 25 | 1.4 (0.5 to 4.6) | 2.4 (1.2 to 4.8) |
| HF | – | 1 | 1 | – | – |
| HF+IPA+P | 6 | 77 | 24 | 1.5 (0.5 to 4.7) | 2.3 (1.1 to 4.7) |
| Age | |||||
| 23–29 years | 15 | 190 | 51 | 1 | 1 |
| <23 years | 11 | 149 | 19 | 0.9 (0.4 to 2.1) | 0.5 (0.3 to 0.8) |
| >29 years | 10 | 132 | 29 | 1.0 (0.4 to 2.2) | 0.8 (0.5 to 1.4) |
| Education | |||||
| High school | 28 | 361 | 80 | 1 | 1 |
| College/university | 8 | 110 | 19 | 0.9 (0.4 to 2.1) | 0.8 (0.5 to 1.3) |
| Current smoking | |||||
| No | 35 | 452 | 93 | 1 | 1 |
| Yes | 1 | 19 | 6 | 0.7 (0.1 to 5.2) | 1.5 (0.6 to 3.9) |
| Current drinking | |||||
| No | 22 | 305 | 65 | 1 | 1 |
| Yes | 14 | 166 | 34 | 1.2 (0.6 to 2.3) | 1.0 (0.6 to 1.5) |
| Current coffee | |||||
| No | 15 | 185 | 43 | 1 | 1 |
| Yes | 21 | 286 | 56 | 0.9 (0.5 to 1.8) | 0.8 (0.5 to 1.3) |
| Current tea | |||||
| No | 9 | 76 | 18 | 1 | 1 |
| Yes | 27 | 395 | 81 | 0.6 (0.3 to 1.3) | 0.9 (0.5 to 1.5) |
| Often extra work | |||||
| No | 19 | 281 | 60 | 1 | 1 |
| Yes | 17 | 190 | 39 | 1.3 (0.7 to 2.6) | 1.0 (0.6 to 1.5) |
| Work pattern | |||||
| Weekday work (8 am–6 pm) | 5 | 82 | 13 | 1 | 1 |
| Day work (7 am–7 pm) | 16 | 202 | 52 | 1.3 (0.5 to 3.7) | 1.6 (0.8 to 3.1) |
| Night work (7 pm–7 am) | 15 | 187 | 34 | 1.3 (0.5 to 3.7) | 1.2 (0.6 to 2.3) |
| Stress level classified by psychiatric score | |||||
| Low | 12 | 221 | 221 | 1 | 1 |
| Medium | 18 | 180 | 180 | 1.8 (0.9 to 3.9) | 1.3 (0.8 to 2.2) |
| High | 6 | 70 | 70 | 1.6 (0.6 to 4.4) | 2.1 (1.2 to 3.8) |
| Body mass index | |||||
| 19–24 kg/m2 | 19 | 273 | 62 | 1 | 1 |
| <19 kg/m2 | 13 | 138 | 22 | 1.4 (0.7 to 2.8) | 0.7 (0.4 to 1.2) |
| >24 kg/m2 | 4 | 60 | 15 | 1.0 (0.3 to 2.9) | 1.1 (0.6 to 2.1) |
| Pregnancy history | |||||
| No | 24 | 292 | 58 | 1 | 1 |
| Yes | 12 | 179 | 41 | 0.8 (0.4 to 1.7) | 1.2 (0.7 to 1.8) |