Table 4  Incidence RR of each DDE quartile of prenatal exposure compared to the first quartile
Unadjusted (n = 199)  Adjusted (n = 177)a
Incidence RR (95% CI)b   Incidence RR (95% CI)b
Infection type  2nd quartile (n = 50)  3rd quartile (n = 50)  4th quartile (n = 50)  p-Value for trendc  2nd quartile (n = 40)  3rd quartile (n = 46)  4th quartile (n = 45)  p-Value for trendc
6-Month follow-up
 URTIs  1.50 (1.05–2.13)  1.06 (0.72–1.55)  1.19 (0.82–1.73)  0.91  1.56 (1.05–2.33)*  1.15 (0.75–1.75)  1.40 (0.90–2.16)  0.24
 Otitis media  1.27 (0.79–2.05)  1.63 (1.04–2.57)*  1.50 (0.95–2.38)  0.04*  1.03 (0.59–1.77)  1.83 (1.09–3.07)*  1.55 (0.90–2.68)  0.07
 GI infections  2.16 (1.02–4.55)*  1.76 (0.81–3.82)  1.67 (0.76–3.64)  0.34  1.91 (0.84–4.35)  1.66 (0.69–3.97)  1.35 (0.54–3.42)  0.58
 LRTIs  1.52 (1.00–2.32)*  1.01 (0.64–1.59)  1.01 (0.64–1.59)  0.75  1.40 (0.86–2.29)  1.22 (0.72–2.05)  0.96 (0.55–1.66)  0.89
 All infectionsd  1.49 (1.19–1.87)*  1.23 (0.97–1.55)  1.25 (0.99–1.57)  0.22  1.38 (1.07–1.78)*  1.33 (1.03–1.73)*  1.27 (0.96–1.67)  0.11
12-Month follow-up
 URTIs  1.27 (0.98– 1.63)  1.03 (0.79– 1.34)  1.11 (0.85–1.44)  0.85  1.34 (1.00–1.78)*  1.09 (0.81–1.47)  1.30 (0.96–1.78)  0.27
 Otitis media  1.00 (0.79–1.27)  1.12 (0.89–1.42)  1.08 (0.85–1.36)  0.36  0.89 (0.68–1.17)  1.08 (0.83–1.41)  1.02 (0.76–1.35)  0.72
 GI infections  1.49 (1.00–2.23)*  1.30 (0.86–1.96)  1.20 (0.79–1.82)  0.98  1.59 (1.03–2.47)*  1.27 (0.81–2.00)  1.43 (0.87–2.34)  0.59
 LRTIs  1.15 (0.85–1.55)  0.96 (0.70–1.30)  1.05 (0.78–1.42)  0.89  1.07 (0.75–1.51)  0.98 (0.69–1.40)  1.00 (0.69–1.45)  0.99
 All infectionsd  1.17 (1.02–1.35)*  1.08 (0.93–1.24)  1.09 (0.95–1.26)  0.59  1.13 (0.97–1.33)  1.08 (0.92–1.26)  1.13 (0.95–1.34)  0.38
CI, confidence interval.
a  Model included mother’s age, season of birth, year of birth, breast-feeding duration, sex, socioeconomic status of the caregiver, tobacco use during pregnancy, village of residence, and number of children living with the participant.
b  Incidence RR when the given quartile was compared to the first quartile of exposure (Poisson regression).
c  p-Values for trends were calculated by Poisson regression in which the contaminant concentration (lipid-based) was entered as a continuous variable (log-transformed).
d  Only infections with a mean incidence > 1.0 episode/year/infant were included; see details in “Materials and Methods”).
*  p < 0.05.