Table 1.
Demographic and medical characteristics of the sample.
| Preterm | Term | Difference | |||
|---|---|---|---|---|---|
| Demographic characteristics | |||||
| Infant chronological age (days) | Newborn | M (SD) | 10.56 (9.63) | 10.14 (9.98) | t(103) = 0.21, p = 0.831, d = 0.05 |
| 5 months | M (SD) | 152.32 (5.91) | 153.22 (6.72) | t(103) = −0.70, p = 0.484, d = −0.14 | |
| Infant gender | Female | N (%) | 16 (39) | 29 (45) | χ2(1, N = 105) = 0.40, p = 0.525 |
| Male | N (%) | 25 (61) | 35 (55) | ||
| Birth order | First born | N (%) | 23 (56) | 42 (66) | χ2(1, N = 105) = 0.96, p = 0.327 |
| Later born | N (%) | 18 (44) | 22 (34) | ||
| Number of siblings | M (SD) | 0.59 (0.97) | 0.44 (0.73) | t(103) = 0.89, p = 0.378, d = 0.17 | |
| Maternal age (years) | M (SD) | 31.63 (5.15) | 32.19 (4.41) | t(103) = −0.59, p = 0.558, d = −0.12 | |
| Marital status | Single | N (%) | 8 (20) | 9 (14) | χ2(2, N = 105) = 0.71, p = 0.700 |
| Co-habiting | N (%) | 6 (15) | 12 (19) | ||
| Married | N (%) | 27 (66) | 43 (67) | ||
| Maternal education | GCSEs | N (%) | 5 (12) | 6 (9) | χ2(3, N = 104) = 1.88, p = 0.598 |
| A-Levels | N (%) | 8 (19) | 7 (11) | ||
| Bachelor's | N (%) | 13 (32) | 25 (40) | ||
| Postgraduate | N (%) | 15 (37) | 25 (40) | ||
| Household income | Less than £14,999 | N (%) | 8 (20) | 4 (6) | χ2(2, N = 102) = 4.73, p = 0.094 |
| £15,000–£39,999 | N (%) | 11 (27) | 16 (26) | ||
| Over £40,000 | N (%) | 21 (53) | 42 (68) | ||
| Maternal ethnicity | Caucasian | N (%) | 35 (95) | 61 (97) | χ2(1, N = 100) = 0.30, p = 0.625 |
| Other | N (%) | 2 (5) | 2 (3) | ||
| Infant medical characteristics | |||||
| Gestational age | M (SD) | 34.45 (1.70) | 39.91 (1.43) | t(103) = −17.69, p < 0.001, d = −3.48 | |
| Birthweight (g) | M (SD) | 2167.66 (467.85) | 3436.85 (568.48) | t(100) = −11.78, p < 0.001, d = −2.44 | |
| Age at discharge (days) | M (SD) | 14.26 (12.49) | 2.76 (3.01) | t(40.94) = 5.64, p < 0.001, d = 1.27 | |
| 5-min Apgar | M (SD) | 9.26 (0.88) | 9.36 (1.47) | t(92) = −0.41, p = 0.685, d = −0.08 | |
| Ventilation (number of days) | M (SD) | 1.54 (3.02) | 0.08 (0.45) | t(35.12) = 2.83, p = 0.008, d = 0.96 | |
Note. Ns for the preterm and term sample were 41 and 64, respectively. Data were missing for maternal education for 1 term infant, and for family income for 1 preterm and 2 term infants, for maternal ethnicity for 4 preterm infants and 1 term infant, for birthweight for 1 preterm infant and 2 term infants, for age at discharge for 2 preterm infants and 5 term infants, for 5-min Apgar scores for 2 preterm and 9 term infants, and for days of ventilation for 6 preterm and 16 term infants.