Table 2.

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.