TABLE 4.
Frequency of night shifts per month | Model 1 | Model 2 | |||
---|---|---|---|---|---|
PR | 95% CI | PR | 95% CI | ||
Irregular cycles | None | Reference | Reference | ||
≤5 nights | 1.84 | 1.29‐2.61 | 1.93 | 1.29‐2.89 | |
6‐7 nights | 1.47 | 0.95‐2.29 | 1.51 | 0.92‐2.48 | |
≥8 nights | 1.14 | 0.79‐1.64 | 1.24 | 0.81‐1.89 | |
Amenorrhea ≥3 mo | None | Reference | Reference | ||
≤5 nights | 2.50 | 0.94‐6.65 | 3.84 | 1.21‐12.22 | |
6‐7 nights | 1.70 | 0.52‐5.59 | 2.07 | 0.58‐7.47 | |
≥8 nights | 0.45 | 0.10‐1.99 | 0.75 | 0.15‐3.66 | |
Abnormal menstrual period | None | Reference | Reference | ||
≤5 nights | 0.76 | 0.24‐2.43 | 0.74 | 0.22‐2.50 | |
6‐7 nights | 1.72 | 0.70‐4.19 | 1.55 | 0.53‐4.51 | |
≥8 nights | 1.41 | 0.69‐2.89 | 1.32 | 0.60‐2.89 | |
Dysmenorrhea or premenstrual symptoms affected their work | None | Reference | Reference | ||
≤5 nights | 1.09 | 0.90‐1.33 | 1.19 | 0.96‐1.48 | |
6‐7 nights | 0.91 | 0.69‐1.20 | 0.98 | 0.73‐1.33 | |
≥8 nights | 1.12 | 0.96‐1.31 | 1.23 | 1.02‐1.49 | |
Often affected | None | Reference | Reference | ||
≤5 nights | 0.77 | 0.31‐1.93 | 1.00 | 0.36‐2.74 | |
6‐7 nights | 0.98 | 0.43‐2.24 | 1.20 | 0.47‐3.06 | |
≥8 nights | 1.51 | 0.90‐2.53 | 1.93 | 1.03‐3.61 |
Model 1: adjusted for age. Model 2: adjusted for age, body mass index, and hospital size, and the department in which women worked.
Abbreviations: CI, confidence interval; PR, prevalence ratio.