Table 5. Crude and adjusted risks of preterm birth according to caffeine consumption. Ribeirão Preto Birth Cohort of 2010.
| Caffeine consumption | Crude Relative Risk | Adjusted Relative Risk | ||||
|---|---|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | Model 4 | |||
| RR (95% CI) | RR1 (95% CI) | RR2 (95% CI) | RR3 (95% CI) | RR4 (95% CI) | ||
| Not consumed | 1 | 1 | 1 | 1 | 1 | |
| < 300 mg/day | 0.99 (0.87–1.13) | 1.07 (0.94–1.22) | 1.10 (0.97–1.25) | 1.11 (0.97–1.26) | 1.10 (0.96–1.26) | |
| ≥ 300 mg/day | 1.16 (0.77–1.75) | 1.16 (0.74–1.80) | 1.12 (0.73–1.69) | 1.12 (0.72–1.73) | 1.03 (0.65–1.63) | |
Abbreviations: CI, confidence interval; RR, relative risk.
Model 1 adjusted for maternal age, education and skin color, marital status, and occupation of the head of the family.
Model 2 adjusted for parity, previous preterm birth, abortion, and stillbirth.
Model 3 adjusted for gestational hypertension and diabetes, threatened abortion and preterm delivery, alcohol consumption, maternal smoking, urinary tract infection and odontological treatments during pregnancy.
Model 4 adjusted for all variables included in the previous models.