Table 2

Multivariate association of socioeconomic factors with CZS, Brazil 2015–2018

Demographic variablesModel 1*Model 2†Model 3‡
OR (95% CI)P valueOR (95% CI)P valueOR (95% CI)P value
Year of birth
 2015111
 20161.34 (1.25 to 1.45)<0.0011.31 (1.21 to 1.42)<0.0011.29 (1.20 to 1.40)<0.001
 20170.31 (0.28 to 0.35)<0.0010.30 (0.27 to 0.34)<0.0010.29 (0.26 to 0.33)<0.001
 20180.16 (0.14 to 0.19)<0.0010.16 (0.14 to 0.19)<0.0010.15 (0.13 to 0.18)<0.001
Sex of the newborn
 Male111
 Female1.19 (1.11 to 1.28)<0.0011.19 (1.11 to 1.28)<0.0011.20 (1.11 to 1.28)<0.001
Birth region
 South111
 Southeast3.83 (3.02 to 4.86)<0.0013.40 (2.66 to 4.33)<0.0013.41 (2.67 to 4.37)<0.001
 North3.19 (2.44 to 4.18)<0.0012.66 (2.01 to 3.53)<0.0012.71 (2.03 to 3.61)<0.001
 Northeast13.51 (10.72 to 17.04)<0.00111.07 (8.66 to 14.13)<0.00111.36 (8.88 to 14.54)<0.001
 Central-west6.47 (5.00 to 8.37)<0.0015.43 (4.15 to 7.10)<0.0015.68 (4.32 to 7.45)<0.001
Maternal race/ethnicity
 White11
 Black1.72 (1.47 to 2.01)<0.0011.46 (1.25 to 1.73)<0.001
 Mixed brown1.37 (1.24 to 1.51)<0.0011.21 (1.09 to 1.34)<0.001
 Asian1.33 (0.75 to 2.36)0.3291.33 (0.75 to 2.36)0.327
 Indigenous1.19 (0.76 to 1.87)0.4420.98 (0.61 to 1.57)0.929
Maternal education (years)
 0–31.20 (0.97 to 1.50)0.094
 4–71.30 (1.13 to 1.50)<0.001
 12–81.28 (1.13 to 1.44)<0.001
 > 121
Maternal marital status
 Married/union1
 Single1.38 (1.28 to 1.49)<0.001
 Widow0.88 (0.33 to 2.34)0.794
 Divorced1.13 (0.75 to 1.69)0.557
No of prenatal appointments
 None2.82 (2.10 to 3.77)<0.001
 1–31.34 (1.18 to 1.51)<0.001
 4–51.14 (1.04 to 1.26)0.006
 6+1
Maternal age (years)
 <201.12 (0.97 to 1.28)0.116
 20–341.02 (0.90 to 1.15)0.773
 35+1

  • *Model 1 is a minimally adjusted model—adjusted for year of birth, region and sex of the newborn.

  • †Model 2—year of birth, region and sex and race.

  • ‡Model 3—year of birth, region and sex, race, maternal education, marital status, maternal age, number of prenatal appointments.

  • CZS, congenital Zika syndrome.