TABLE 2

Prevalence of Past-Year Infections Among 6-Year-Old US Children According to Breastfeeding Practices, IFPS II (2005–2007) and Y6FU (2012)

VariableN (%)Past-Year Infections at Age 6 Years (%)
Cold or Upper Respiratory TractEarThroatSinusPneumonia or LungUrinary Tract
Total1281 (100)65.725.123.715.64.63.8
Ever breastfed
 No175 (13.6)65.728.029.722.34.64.6
 Yes1106 (86.4)65.724.622.814.64.63.7
P = .99aP = .33P = .04bP < .01bP = .98P = .58
Duration of any breastfeeding1106 (100)
 >0 to <3 mo311 (28.1)65.628.126.120.94.84.5
 3 to <6 mo143 (12.9)58.028.025.215.44.92.8
 6 to <9 mo134 (12.1)67.924.623.113.42.23.7
 ≥9 mo518 (46.9)67.421.420.110.85.03.5
P = .32P = .02bP = .04bP < .01bP = .97P = .55
Duration of exclusive breastfeeding1106 (100)
 >0 to <4 mo868 (78.5)65.426.424.215.94.83.5
 4 to <6 mo195 (17.6)65.119.520.011.34.15.1
 ≥6 mo43 (3.9)74.411.67.02.32.32.3
P = .44P < .01bP < .01bP < .01bP = .41P = .63
Formula supplementation1106 (100)
 Breastfed <6 mo with formula before 6 mo445 (40.2)63.828.125.819.14.94.0
 Breastfed ≥6 mo with formula before 6 mo285 (25.8)66.024.623.513.05.33.9
 Breastfed ≥6 mo without formula before 6 mo376 (34.0)67.820.518.610.43.73.2
P = .23P = .01bP = .01bP < .01bP = .42P = .52
Breast milk intensity (% milk feedings being breast milk) during the first 6 mo1106 (100)
 Low (>0 to <33.3%)309 (27.9)64.428.225.920.75.24.5
 Medium (33.3% to 66.6%)120 (10.8)61.726.725.815.05.04.2
 High (>66.6%)677 (61.3)67.122.620.811.74.33.3
P = .35P = .05P = .06P < .01bP = .52P = .31
  • a P value from the χ2 test for the association between infant feeding and infection.

  • b P < .05 is considered statistically significant