Table 5.
Adjusted hazard ratios and 95%CI for any breastfeeding duration
| Characteristic | HR | 95%CI | P value |
| Maternal age (per year) | 1.01 | 0.97 to 1.05 | P = 0.779 |
| BMI before pregnancy (per kg/m2) | 1.01 | 0.97 to 1.05 | P = 0.600 |
| Maternal educational status | |||
| High school graduate or lower | 1.00 | ||
| University/college education | 0.53 | 0.37 to 0.76 | P = 0.001 |
| Postgraduate degree | 0.20 | 0.09 to 0.43 | P < 0.001 |
| Maternal employment status | |||
| Unemployed/domestically occupied | 1.00 | P = 0.213 | |
| Employed | 0.76 | 0.50 to 1.17 | |
| Maternal nationality | |||
| Greek | 1.00 | ||
| Immigrant | 0.35 | 0.21 to 0.38 | P < 0.001 |
| Smoking before pregnancy | |||
| No | 1.00 | ||
| Yes | 0.49 | 0.20 to 1.22 | P = 0.124 |
| Smoking during follow-up | |||
| No | 1.00 | ||
| Yes | 4.20 | 2.57 to 6.89 | P < 0.001 |
| Maternal psychological problems | |||
| No | 1.00 | ||
| Yes | 1.72 | 1.23 to 2.41 | P = 0.002 |
| Previous breastfeeding experience | |||
| No | 1.00 | P = 0.069 | |
| Yes | 0.69 | 0.46 to 1.03 | |
| Breastfeeding encouragement | |||
| No | 1.00 | ||
| Yes | 0.98 | 0.60 to 1.58 | P = 0.916 |
| Multiparity | |||
| Singleton | 1.00 | ||
| Twins | 1.83 | 0.89 to 3.74 | P = 0.099 |
| Prematurity | |||
| Full-term | 1.00 | P = 0.088 | |
| Premature | 1.65 | 0.93 to 2.93 | |
| Pacifier introduction | |||
| No | 1.00 | ||
| Yes | 2.08 | 1.40 to 3.08 | P < 0.001 |