Table 4.
Odds ratios of weekly working hours on preterm birth
| Crude | Adjusted | ||||
|---|---|---|---|---|---|
| OR | 95% CI | OR | 95% CI | ||
| Weekly working hours | |||||
| 71≤ | 4.38 | (2.08-9.24) | 4.19 | (1.91-9.21) | |
| 51-70 | 2.50 | (1.20-5.24) | 2.46 | (1.16-5.23) | |
| 41-50 | 1.48 | (0.67-3.30) | 1.44 | (0.63-3.31) | |
| ≤40 | 1.00 | ― | 1.00 | ― | |
| Specialty groupa | |||||
| Surgery | 0.93 | (0.44-1.95) | 0.74 | (0.34-1.62) | |
| General medicine | 1.11 | (0.54-2.31) | 0.86 | (0.40-1.83) | |
| Others | 1.00 | ― | 1.00 | ― | |
| Maternal age, years | |||||
| 33≤ | 0.78 | (0.37-1.66) | 1.23 | (0.51-3.00) | |
| 30-32 | 1.14 | (0.57-2.30) | 1.65 | (0.71-3.83) | |
| 28-29 | 1.59 | (0.77-3.28) | 2.39 | (0.99-5.75) | |
| <28 | 1.00 | ― | 1.00 | ― | |
| Current household income | |||||
| Lowest quintile | 2.92 | (0.88-9.69) | 2.90 | (0.76-11.08) | |
| Second lowest quintile | 0.93 | (0.27-3.16) | 0.96 | (0.27-3.44) | |
| Middle | 2.51 | (1.08-5.85) | 2.38 | (1.00-5.66) | |
| Second highest quintile | 1.22 | (0.56-2.65) | 1.06 | (0.48-2.35) | |
| Highest quintile | 1.00 | ― | 1.00 | ― | |
"Crude" incdicates univariate analyses and "Adjusted" indicates all variables in the model; Subjects with preterm birth were excluded in the model where threatened abortion was dependent variable; Similarly, subjects with threatened abortion were excluded in the model where preterm birth was dependent variable.
aSpecialty group consists of "Surgery" including General Surgery, Otorhinolaryngology, Dermatology, Urology, OBGY, Opthalmology, Orthopedic Surgery, Plastic Surgery, Cosmetic Surgery, and Neurosurgery, "General Medicine" including Internal medicine, Pediatrics, Psychosomatic Medicine, Family Medicine, Neurology, and Palliative Care, and “Others” including Psychiatry, Anesthesiology, Radiology, Basic medicine, Rehabilitation, Emergency Medicine, and those who has not chosen specialty yet.