Poisson regression analyses of preterm and early-term births according to municipal CS rates, Brazil 2015
| Municipal CS prevalence rates | Preterm births | Early-term births | ||||||
| Crude analyses | Adjusted analyses* | Crude analyses | Adjusted analyses * | |||||
| Prevalence ratio | 95% CI | Prevalence ratio | 95% CI | Prevalence ratio | 95% CI | Prevalence ratio | 95% CI | |
| 80% | 1.145 | 1.108 to 1.184 | 1.215 | 1.174 to 1.257 | 1.89 | 1.859 to 1.921 | 1.643 | 1.616 to 1.671 |
| 70%–79% | 1.115 | 1.087 to 1.143 | 1.174 | 1.143 to 1.205 | 1.615 | 1.593 to 1.639 | 1.398 | 1.378 to 1.419 |
| 60%–69% | 1.199 | 1.171 to 1.227 | 1.243 | 1.213 to 1.274 | 1.514 | 1.493 to 1.535 | 1.31 | 1.292 to 1.329 |
| 50%–59% | 1.139 | 1.113 to 1.166 | 1.197 | 1.169 to 1.227 | 1.404 | 1.385 to 1.423 | 1.224 | 1.207 to 1.241 |
| 40%–49% | 1.095 | 1.069 to 1.122 | 1.136 | 1.108 to 1.165 | 1.22 | 1.203 to 1.238 | 1.113 | 1.097 to 1.129 |
| 30%–39% | 1.076 | 1.047 to 1.105 | 1.09 | 1.060 to 1.122 | 1.12 | 1.102 to 1.138 | 1.043 | 1.026 to 1.060 |
| <30% | 1.0 | 1.0 | 1.0 | 1.0 | ||||
All p values <0.0001.
↵*Adjusted for maternal schooling, maternal age, parity, marital status.
CS, caesarean sections.