Predictors of exclusive breastfeeding: observations from the Alberta pregnancy outcomes and nutrition (APrON) study

Table 4 Direct (forced-entry) logistic regression analysis of best-fitting model for predictors of 6-month exclusive breastfeeding among a subsample of participants from the first cohort of Alberta Pregnancy Outcomes and Nutrition (APrON) study ^*,†

Model, predictor	β ¹	SE ²	Wald	p-value	Exp (B) ³	95% CI ⁴
*Model 1*
IIFAS score	0.08	0.03	9.76	0.002	1.08	1.03-1.14
Constant	-6.96	1.75	15.86	0.000	0.001	1.03-1.14
*Model 2*
IIFAS score	0.07	0.03	8.78	0.003	1.08	1.03-1.13
Multiparity	0.63	0.35	3.30	0.070	1.88	0.95-3.73
Constant	-7.01	1.75	15.96	0.000	0.001	0.95-3.73
*Model 3*
IIFAS score	0.07	0.03	7.82	0.005	1.08	1.02-1.13
Multiparity	0.77	0.36	4.54	0.033	2.16	1.06-4.39
Completed university undergraduate degree	0.58	0.51	1.29	0.257	1.79	0.66-4.87
Completed university post-graduate degree	1.50	0.53	7.91	0.005	4.46	1.57-12.63
Constant	-7.77	1.92	16.46	0.000	0.000	1.57-12.63
*Model4* ⁵
IIFAS score	0.07	0.03	7.70	0.006	1.08	1.02-1.13
Multiparity	0.79	0.37	4.65	0.031	2.21	1.08-4.52
Completed university undergraduate degree	0.52	0.52	1.00	0.318	1.68	0.61-4.63
Completed university post-graduate degree	1.33	0.54	5.93	0.015	3.76	1.30-10.92
Pre-pregnancy BMI⁶	-0.05	0.05	1.30	0.255	0.95	0.87-1.04
Constant	-6.52	2.30	8.05	0.005	0.001	0.87-1.04

IIFAS: Iowa Infant Feeding Attitude Scale; BMI: body mass index.
^*Reference categories include: parity (primiparous); education (less than secondary education).
^†IIFAS score and pre-pregnancy BMI were entered into models as continuous variables, while multiparity and maternal education were entered as categorical factors.
¹Coefficient of regression.
²Standard error.
³Exponential value of β.
⁴95% confidence interval of the exponential value.
⁵Nagelkerke R2 =0.16; Hosmer-Lemeshow test: (X² = 13.31, p = 0.10); positive predictive value = 60.00%; negative predictive value = 84.67%.
⁶BMI was calculated by dividing the weight in kilograms by square of height in meters.

ISSN: 1471-2431