Table 1.
Baseline Characteristics of Infant and Mother (New Zealand and Australia Combined)
| Variables | Intervention group, N = 145 (%) | Usual care group, N = 148 (%) |
|---|---|---|
| Infants: female | 58 (40) | 68 (46) |
| Infants: mean age at baseline, weeks (SD) | 6.3 (2.7) | 6.0 (2.7) |
| Infants: country | ||
| New Zealand | 108 (74) | 108 (73) |
| Australia | 37 (26) | 40 (27) |
| Infants: mean gestational age at birth, weeks (SD) | 39.3 (1.3) | 39.3 (1.5) |
| Infants: mean birth weight, kilograms (SD) | 3.3 (0.5) | 3.3 (0.6) |
| Infants: unwell since birtha | 44 (30) | 36 (24) |
| Infants: coughing | ||
| No daytime cough | 111 (77) | 119 (80) |
| No nighttime cough | 123 (85) | 128 (87) |
| Mothers: mean age at baseline in years (SD) | 26.8 (6.5) | 25.3 (5.8) |
| Mothers: highest level of education | ||
| ≤Secondary school | 104 (72) | 114 (77) |
| TAFE/polytechnic/university | 41 (28) | 34 (23) |
| Mothers: marital statusb | ||
| Married/defacto/living with partner | 72 (50) | 91 (62) |
| Divorced/separated/widowed | 8 (6) | 20(14) |
| Never married | 44 (30) | 25 (17) |
| Refused to answerc | 21 (15) | 12 (8) |
| Mothers: breast feeding state | ||
| Yes—exclusive | 43 (30) | 49 (33) |
| Yes—full | 29 (20) | 31 (21) |
| Yes—partial | 42 (29) | 40 (27) |
| No | 31 (21) | 28 (19) |
| Mothers: smoked during pregnancy | 114 (79) | 105 (71) |
| Mothers: reduced amount smoked during pregnancye | 74 (65) | 71 (68) |
| Mothers: current smoking status | ||
| Current smoker | 105 (72) | 88 (60) |
| Ex-smoker | 22 (15) | 37 (25) |
| Never smoked | 18 (12) | 23 (16) |
| Mothers: frequency of smokingf | ||
| At least weekly | 95 (90) | 83 (94) |
| Less than weekly | 10 (10) | 5 (6) |
| Mothers: number of cigarettes smoked per dayf | ||
| ≤10 | 54 (51) | 63 (72) |
| 11–20 | 38 (35) | 20 (23) |
| 21–30 | 6 (6) | 2 (2) |
| ≥31 | 1 (1) | 1 (1) |
| Missing data | 6 (6) | 2 (2) |
| Mothers: time to first cigarettef | ||
| ≤30min of waking | 48 (49) | 31 (37) |
| >30min of waking | 50 (51) | 53 (63) |
| Mothers: quit attempt in last 12 monthsf | 49 (47) | 44 (50) |
| Mothers: mean self-efficacy score (SD)g | 3.3 (0.8) | 3.3 (0.8) |
| Household: mean crowding index (SD)d | 2.0 (0.7) | 2.0 (0.7) |
| Household: mean number of children in house aged under 5 years (SD) | 1.9 (1.0) | 1.9 (1.0) |
SD = standard deviation; TAFE = Technical and Further Education Institution.
aThe specific question was “Has your infant been unwell and needed to go to the health clinic, general practitioner or hospital since he/she was born?”
b X 2; p = .002.
cAll but three participants were from New Zealand. In New Zealand, different levels of social support are offered depending on marital status. It is likely that some women in the study did not wish to disclose their marital status, in case their access to certain social support was jeopardized.
dDefined as the number of people currently sleeping in the house divided by the number of rooms in the house where people were sleeping
eIn those that smoked during pregnancy.
fIn current smokers.
gBelief in their ability to quit this time, measured on a scale of 1–5, where one was very low and five was very high.