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. 2014 Jan 8;99(3):524–534. doi: 10.3945/ajcn.113.071191

TABLE 5.

Unadjusted and adjusted models for the association of maternal prepregnancy BMI and PSFs with intention to breastfeed, ever breastfed, and duration of EBF and ABF in all participants1

Outcome
Predictor Intention to breastfeed (n = 2824)23 Ever breastfed (n = 2824)24 Duration of EBF (n = 1258)56 Duration of ABF (n = 2423)57
BMI category
 Unadjusted model8
 P 0.07 0.04 0.0009 0.03
 Underweight/normal weight Reference Reference Reference Reference
 Overweight 1.05 (0.80, 1.37) 1.08 (0.83, 1.41) 1.12 (0.97, 1.29) 1.14 (1.01, 1.28)
 Obese 0.77 (0.59, 1.00) 0.76 (0.60, 0.98) 1.32 (1.14, 1.52) 1.16 (1.02, 1.31)
 n 2824 2824 1258 2423
 Model adjusted for all PSFs9
 P 0.26 0.17 0.02 0.79
 Underweight/normal weight Reference Reference Reference Reference
 Overweight 1.32 (0.92, 1.90) 1.32 (0.95, 1.84) 1.06 (0.92, 1.23) 1.00 (0.88, 1.13)
 Obese 0.98 (0.69, 1.41) 0.95 (0.69, 1.32) 1.25 (1.07, 1.46) 1.04 (0.91, 1.19)
 n 2801 2801 1176 2225
 Final adjusted model10
 P 0.74 0.64 0.01 0.31
 Underweight/normal weight Reference Reference Reference Reference
 Overweight 1.03 (0.66, 1.59) 1.07 (0.63, 1.84) 1.09 (0.93, 1.27) 1.00 (0.87, 1.15)
 Obese 0.87 (0.57, 1.33) 0.82 (0.49, 1.38) 1.29 (1.09, 1.53) 1.11 (0.96, 1.29)
 n 2487 2466 1000 1785
Social knowledge
 Unadjusted model8
 P <0.0001 <0.0001 <0.0001 <0.0001
 >5 people Reference Reference Reference Reference
 3–5 people 0.29 (0.20, 0.42) 0.36 (0.25, 0.51) 1.48 (1.28, 1.70) 1.64 (1.45, 1.86)
 1–2 people 0.14 (0.10, 0.21) 0.18 (0.13, 0.25) 1.64 (1.39, 1.93) 1.88 (1.64, 2.15)
 0 people/do not know 0.12 (0.08, 0.17) 0.13 (0.09, 0.19) 1.86 (1.52, 2.27) 2.16 (1.84, 2.54)
 n 2801 2801 1247 2400
 Model adjusted for BMI and all PSFs9
 P <0.0001 <0.0001 <0.0001 <0.0001
 >5 people Reference Reference Reference Reference
 3–5 people 0.42 (0.27, 0.67) 0.55 (0.37, 0.82) 1.45 (1.25, 1.69) 1.49 (1.30, 1.69)
 1–2 people 0.24 (0.15, 0.38) 0.31 (0.21, 0.46) 1.64 (1.38, 1.94) 1.63 (1.41, 1.88)
 0 people/do not know 0.28 (0.17, 0.45) 0.30 (0.19, 0.45) 1.61 (1.30, 1.99) 1.63 (1.37, 1.94)
 n 2801 2801 1176 2225
 Final adjusted model10
 P 0.02 0.55 0.001 0.0003
 >5 people Reference Reference Reference Reference
 3–5 people 0.54 (0.32, 0.92) 0.97 (0.53, 1.78) 1.31 (1.11, 1.54) 1.35 (1.17, 1.56)
 1–2 people 0.44 (0.26, 0.74) 0.73 (0.39, 1.35) 1.36 (1.13, 1.64) 1.22 (1.04, 1.44)
 0 people/do not know 0.50 (0.28, 0.88) 0.68 (0.34, 1.36) 1.20 (0.95, 1.53) 1.37 (1.12, 1.67)
 n 2487 2466 1000 1785
Social influence
 Unadjusted model8
 P <0.0001 <0.0001 <0.0001 <0.0001
 High Reference Reference Reference Reference
 Medium 0.10 (0.05, 0.23) 0.25 (0.16, 0.42) 1.27 (1.12, 1.44) 1.19 (1.06, 1.34)
 Low 0.01 (0.01, 0.02) 0.03 (0.02, 0.05) 1.52 (1.29, 1.79) 1.56 (1.37, 1.78)
 n 2824 2824 1258 2423
 Model adjusted for BMI and all PSFs9
 P <0.0001 <0.0001 0.12 0.53
 High Reference Reference Reference Reference
 Medium 0.18 (0.08, 0.40) 0.42 (0.25, 0.70) 1.12 (0.98, 1.28) 0.96 (0.85, 1.08)
 Low 0.03 (0.01, 0.06) 0.09 (0.05, 0.14) 1.16 (0.98, 1.40) 1.03 (0.89, 1.20)
 n 2801 2801 1176 2225
 Final adjusted model10
 P <0.0001 0.02 0.04 0.99
 High Reference Reference Reference Reference
 Medium 0.16 (0.06, 0.44) 0.73 (0.37, 1.43) 1.20 (1.04, 1.38) 0.99 (0.87, 1.13)
 Low 0.03 (0.01, 0.06) 0.42 (0.21, 0.83) 1.15 (0.95, 1.39) 0.99 (0.84, 1.16)
 n 2487 2466 1000 1785
Attitude/behavioral beliefs
 Unadjusted model8
 P <0.0001 <0.0001 <0.0001 <0.0001
 Good Reference Reference Reference Reference
 Fair 0.10 (0.07, 0.14) 0.13 (0.10, 0.17) 2.04 (1.72, 2.41) 2.10 (1.86, 2.37)
 Poor 0.02 (0.01, 0.03) 0.03 (0.02, 0.04) 2.18 (1.56, 3.05) 2.50 (2.03, 3.07)
 n 2824 2824 1258 2423
 Model adjusted for BMI and all PSFs9
 P <0.0001 <0.0001 <0.0001 <0.0001
 Good Reference Reference Reference Reference
 Fair 0.18 (0.13, 0.26) 0.22 (0.16, 0.30) 1.77 (1.47, 2.13) 1.76 (1.54, 2.01)
 Poor 0.04 (0.03, 0.06) 0.07 (0.05, 0.10) 2.01 (1.41, 2.86) 1.75 (1.37, 2.25)
 n 2801 2801 1176 2225
 Final adjusted model10
 P <0.0001 0.002 0.002 0.07
 Good Reference Reference Reference Reference
 Fair 0.22 (0.15, 0.34) 0.41 (0.25, 0.67) 1.28 (1.04, 1.58) 1.17 (1.01, 1.37)
 Poor 0.05 (0.03, 0.08) 0.50 (0.26, 0.97) 1.81 (1.22, 2.69) 1.22 (0.91, 1.63)
 n 2487 2466 1000 1785
Maternal confidence11
 Unadjusted model8
 P <0.0001 <0.0001
 Confident Reference Reference
 Neutral 1.74 (1.50, 2.02) 2.08 (1.84, 2.34)
 Not confident 2.02 (1.53, 2.68) 2.98 (2.48, 3.59)
 n 1186 2246
 Model adjusted for BMI and all PSFs9
 P <0.0001 <0.0001
 Confident Reference Reference
 Neutral 1.56 (1.33, 1.82) 1.81 (1.60, 2.04)
 Not confident 1.66 (1.24, 2.21) 2.50 (2.07, 3.02)
 n 1176 2225
 Final adjusted model10
 P 0.02 <0.0001
 Confident Reference Reference
 Neutral 1.27 (1.07, 1.51) 1.32 (1.15, 1.52)
 Not confident 1.16 (0.84, 1.61) 1.68 (1.34, 2.09)
 n 1000 1785
1

Values are ORs; 95% CIs in parentheses for intention to breastfeed and ever breastfed; values are HRs; 95% CIs in parentheses for duration of EBF and duration of ABF. ABF, any breastfeeding; EBF, exclusive breastfeeding; PSF, psychosocial factor.

2

Logistic regression models that predicted the odds of intention to breastfeed and ever breastfed.

3

All final models were adjusted for education, income, race-ethnicity, smoking status, and past breastfeeding experience.

4

All final models were adjusted for race-ethnicity, planned return to work, past breastfeeding experience, prenatal infant-feeding intention, and marital status.

5

Cox proportional hazard models that predicted the hazard of earlier cessation of EBF and ABF.

6

All final models were adjusted for marital status, education, intended duration of breastfeeding, and actual return time to work.

7

All final models were adjusted for intended duration of breastfeeding, actual return time to work, education, past breastfeeding experience, gestation duration, and marital and smoking status.

8

Unadjusted model of the single predictor with each outcome.

9

Model was adjusted to include BMI and psychosocial variables for each outcome.

10

Best-fitting model for each outcome was determined by using the Akaike information criterion score. Models included BMI and psychosocial variables as well as particular covariates as described in footnotes 3, 4, 6, and 7.

11

Maternal confidence was not used as a predictor for outcomes of intention to breastfeed or ever breastfed because only women with a prenatal intention to breastfeed responded to the question about their breastfeeding confidence.