Maternal recall of breastfeeding duration twenty years after delivery

Table 1 Maternal and child characteristics of responders, non-responders and eligible participants

Variables	Responders^a (n=374)	Non-responders^b (n=263)	P-value^c	Eligible participants (n=981)
Maternal characteristics ^d
Age at delivery, yrs, mean (SD)	29.1 (3.9)	28.7 (4.4)	0.327	29.1 (4.1)
Pre-pregnancy BMI, kg/m², mean (SD)	21.2 (2.8)	21.2 (2.9)	0.949	21.1 (2.9)
College/ university education, n (%)	44 (26.5)	48 (18.3)	0.001	240 (24.5)
Never smokers, n (%)	108 (28.9)	42 (16.0)	<0.001	254 (25.9)
Married/cohabiting^e, n (%)	330 (88.2)	224 (85.2)	0.076	856 (87.3)
No breastfeeding^f, n (%)	0	1 (0.4)		1 (0.001)
Breastfeeding duration^f , months, median (IQR)	6.0 (6.0)	5.0 (5.0)	<0.001	6.0 (5.8)
Child characteristics, index pregnancy ^d
Birth weight, g, mean (SD)	3440.7 (611.3)	3382.1 (595.4)	0.229	3424.1 (625.2)
Preterm birth of child, n (%)	15 (4.0)	14 (5.4)	0.434	62 (6.3)
SGA^g, n (%)	64 (17.1)	52 (19.8)	0. 406	132 (13.6)
Gender,
Boy, n (%)	167 (44.7)	140 (53.2)	0.033	490 (49.9)
Girl, n (%)	207 (55.3)	123 (46.8)		491 (50.1)
Birth order of index child,
2^nd birth, n (%)	282 (75.4)	191 (72.6)	0.462	704 (71.8)
3^rd birth, n (%)	92 (24.6)	72 (27.4)		277 (28.2)
Age at introduction of cereals, months, median (IQR)^h	4.0 (1.0)	4.0 (1.0)	0.140	4.0 (1.0)
Age at introduction of another kind of milk, months, median (IQR)ⁱ	5.0 (4.5)	2.5 (5.0)	<0.001	4.0 (4.8)

Abbreviations’: SD, standard deviation; BMI, body mass index; IQR, interquartile range; SGA, small for gestational age.
^a Responders with complete recorded breastfeeding data.
^b Non-responders with complete recorded breastfeeding data.
^c P-value assessed using Chi-square test (categorical data) and independent samples t-test or the non-parametric Mann Whitney test (continuous data).
^d Background variables reported in parent study. Continuous variables presented as mean (SD) or median (IQR), categorical variables presented as n (%).
^e Number of women with unknown marital status: among responders: 39, among non-responders: 28
^f Number of women still breastfeeding at 13 months and therefore excluded in analysis of this variable: among responders: 29, among non-responders: 1. Number of missing data among eligible participants: 351.
^gSGA defined as birth weight <10 percentile for gestational age, gender and parity [20]
^h Numbers with missing data on infant’s age at introduction of cereals: among responders: n=16, among non-responders: n=15. Number of missing data among eligible participants: 229.
ⁱ Numbers with missing data on infant’s age at introduction of another kind of milk: among responders: n=36, among non-responders: n=19. Number of missing data among eligible participants: 261.

ISSN: 1471-2288