| Outcome | Group | Adjusted comparative statistic (intervention relative to control) | |||
| Intervention | Control | Statistic (95% CI) | p Value | ICC | |
| 10 months | |||||
| Sleep problem, n (%) | 92 (56) | 100 (68) | 0.58 (0.36, 0.94) | 0.03 | 0 |
| Global Infant Temperament score, mean (SD) | 2.7 (0.9) | 2.9 (0.9) | −0.1 (−0.3, 0.1) | 0.31 | 0.028 |
| EPDS score >9, n (%) | 46 (28) | 51 (35) | 0.63 (0.35, 1.12) | 0.11 | 0 |
| Total EPDS score at 2 months, mean (SD) | 6.8 (5.1) | 7.8 (5.5) | −1.4 (−2.3, −0.4) | 0.007 | 0 |
| Poor/fairly poor sleep quality, n (%) | 102 (63) | 104 (72) | 0.69 (0.41, 1.15) | 0.16 | 0 |
| Not enough/not nearly enough sleep, n (%) | 64 (40) | 66 (46) | 0.76 (0.46, 1.24) | 0.27 | 0.009 |
| SF12 – physical health, mean (SD) | 51.6 (7.3) | 51.5 (7.6) | 0.2 (−1.6, 2.0) | 0.83 | 0.017 |
| SF12 – mental health, mean (SD) | 48.1 (10.3) | 45.0 (11.0) | 3.7 (1.5, 5.8) | 0.001 | 0 |
| 12 months | |||||
| Sleep problem, n (%) | 64 (39) | 80 (55) | 0.50 (0.31, 0.80) | 0.004 | 0 |
| Global Infant Temperament score, mean (SD) | 2.7 (0.9) | 2.9 (0.9) | −0.2 (−0.4, 0.0) | 0.07 | 0 |
| EPDS score >9, n (%) | 41 (25) | 41 (28) | 0.71 (0.39, 1.30) | 0.26 | 0 |
| Total EPDS score, mean (SD) | 5.9 (4.8) | 7.2 (5.2) | −1.7 (−2.6, −0.7) | 0.001 | 0 |
| Poor/fairly poor sleep quality, n (%) | 83 (52) | 92 (63) | 0.52 (0.32, 0.86) | 0.01 | 0 |
| Not enough/not nearly enough sleep, n (%) | 55 (34) | 65 (45) | 0.55 (0.33, 0.92) | 0.02 | 0 |
| SF12 – physical health, mean (SD) | 50.8 (7.2) | 52.7 (6.7) | −1.7 (−3.3, −0.1) | 0.04 | 0 |
| SF12 – mental health, mean (SD) | 49.7 (9.2) | 46.1 (10.7) | 3.9 (1.8, 6.1) | <0.001 | 0.001 |
The comparative statistic is mean difference for quantitative outcomes and odds ratio for dichotomous outcomes.
Sample size ranged from 148 to 159 in the intervention arm and 138 to 144 in the control arm at 10 months and ranged from 145 to 154 in the intervention arm and 134 to 139 in the control arm at 12 months. Analyses adjusted for whether the mother received paid professional help for the infant’s sleep problem at the time of follow-up and perceived nurse competency. Analysis of sleep problem was additionally adjusted for Socio-Economic Indexes For Areas (SEIFA) Index of Relative Disadvantage code and mother’s educational level. Analyses of maternal EPDS score, sleep quality, sleep quantity, and SF12 physical and health scores were additionally adjusted for baseline EPDS total score. Analyses of Global Infant Temperament score were additionally adjusted for baseline EPDS total score and Global Infant Temperament at baseline. EPDS, Edinburgh Postnatal Depression Scale.
Negative estimates of the intraclass correlation coefficient (ICC) are truncated at zero.