Table 3 Sample characteristics by randomisation group at baseline (7 months)*
VariableRandomisation
Control(n = 154)Intervention(n = 174)
Infant
    Infant age, mean (SD)7.3 (0.6)7.4 (0.6)
    Male, n (%)89 (58)89 (51)
    Birth weight (g), mean (SD)3432 (488)3461 (507)
    Family position, n (%)
        First72 (47)83 (48)
        Second55 (36)54 (31)
        Third or more25 (16)37 (21)
    Exclusively breast feeding (at93 (60)104 (60)
    4 months), n (%)
    Difficult temperament, n (%)44 (29)40 (23)
Infant sleep
    Sleep problem severity, n (%)
        Mild37 (24)38 (22)
        Moderate58 (38)66 (38)
        Severe59 (38)70 (40)
    Number of waking nights/week
    Median (IQR)7 (5–7)7 (5–7)
        0–3, n (%)22 (14)28 (16)
        4–6, n (%)44 (29)46 (26)
        7, n (%)88 (57)100 (57)
Who responds to waking infant overnight?
        Mother, n (%)135 (91)155 (90)
        Father, n (%)6 (4)3 (2)
        Both parents, n (%)8 (5)15 (9)
    Sleep site, n (%)
        Cot in own/sibling’s room101 (66)122 (71)
        Parent’s room36 (24)30 (17)
        Parent’s bed16 (10)20 (12)
Family
    Maternal age (years), mean (SD)33.2 (4.8)32.8 (4.3)
    Relationship status, n (%)
        Married/de facto145 (97)172 (99)
    Parents’ country of birth
    (mother’s/father’s), n (%)
        Australia or New Zealand124 (81)/139 (80)/
124 (82)137 (79)
    Language other than English31 (20)32 (18)
    at home, n (%)
    Education status (mother’s/
    father’s), n (%)
        Did not complete high school28 (18)/43 (28)29 (17)/49 (29)
        Completed high school only51 (33)/44 (29)53 (30)/45 (26)
        Completed tertiary/75 (49)/66 (43)92 (53)/77 (45)
        postgraduate degree
    Socioeconomic status (SEIFA
    ranking), n (%)
        Low35 (23)24 (14)
        Medium41 (27)63 (36)
        High78 (51)87 (50)
Maternal health
    Past history of depression, n (%)32 (21)36 (21)
    EPDS
        Mean (SD)8.4 (5.1)8.4 (5.3)
        Median (IQR)8 (4–12)8 (4–12)
        >9 (n (%))64 (42)66 (38)
    Maternal sleep, n (%)
        Quality
            Fairly/very good74 (48)77 (44)
            Very/fairly bad80 (52)97 (56)
        Quantity
            Enough/more than enough19 (12)34 (20)
            Not nearly/not quite enough135 (88)140 (80)
MCH centres, n
    MCH centre clusters2425
    Nurses3138
    Families154174
    Nurses per MCH centre cluster
        Mean (SD)1.35 (0.49)1.52 (0.65)
        Range1–21–3
  • *Sample size ranged from 299 to 328.

  • EPDS, Edinburgh Postnatal Depression Scale; IQR, interquartile range; MCH, Maternal and Child Health.