Descriptive statistics for Griffiths scales of mental development at 18 months of age and associations with confounding factors
| Performance on Griffiths scales | ||||||
|---|---|---|---|---|---|---|
| Scale A (L) | Scale B (HS) | Scale C (HE) | Scale D (P) | Scale E (S) | DQ | |
| Overall | ||||||
| Mean (SD) | 112 (10.1) | 100 (16.1) | 107 (10.3) | 114 (12.7) | 106 (10.9) | 108 (8.8) |
| N | 1141 | 1141 | 1141 | 1141 | 1141 | 1141 |
| Range | 64–136 | 63–133 | 64–134 | 64–136 | 64–131 | 65–130 |
| Confounders | ||||||
| Parity | ||||||
| 0 | 112 (9.8) | 103 (16.6) | 106 (10.2) | 114 (13.0) | 107 (10.5) | 108 (8.9) |
| 1 | 112 (9.8) | 99 (15.3) | 107 (9.9) | 115 (11.9) | 106 (10.9) | 108 (8.5) |
| 2+ | 112 (11.2) | 95 (15.0) | 106 (10.6) | 112 (12.8) | 104 (11.3) | 106 (8.9) |
| 0.711 | <0.0001 | 0.505 | 0.080 | 0.005 | 0.001 | |
| Sex | ||||||
| Male | 112 (10.2) | 96 (15.3) | 106 (10.1) | 113 (13.2) | 104 (10.8) | 106 (8.6) |
| Female | 112 (9.8) | 104 (16.1) | 107 (10.4) | 115 (11.9) | 108 (10.5) | 109 (8.7) |
| 0.891 | <0.0001 | 0.002 | 0.004 | <0.0001 | <0.0001 | |
| Ethnicity | ||||||
| White | 112 (10.1) | 100 (16.2) | 107 (10.3) | 114 (12.8) | 106 (10.9) | 108 (8.8) |
| Non-white | 113 (12.5) | 98 (17.0) | 106 (10.1) | 114 (12.1) | 107 (11.2) | 108 (9.2) |
| 0.8 | 0.4 | 0.9 | 0.9 | 0.6 | 0.9 | |
| Breast fed | ||||||
| No | 111 (9.9) | 97 (15.6) | 106 (10.3) | 111 (13.5) | 103 (12.1) | 106 (9.2) |
| Yes | 112 (10.2) | 101 (16.1) | 107 (10.2) | 114 (12.5) | 107 (10.4) | 108 (8.6) |
| 0.08 | 0.001 | 0.1 | 0.001 | <0.0001 | <0.0001 | |
| Smoking | ||||||
| No | 112 (10.2) | 100 (16.2) | 106 (10.4) | 114 (12.6) | 106 (10.8) | 108 (8.9) |
| Yes | 112 (10.0) | 98 (15.5) | 107 (9.0) | 112 (12.5) | 106 (10.9) | 107 (8.0) |
| 0.8 | 0.1 | 0.9 | 0.03 | 0.6 | 0.2 | |
| Maternal education | ||||||
| A | 111 (11.3) | 93 (14.0) | 104 (10.4) | 110 (13.9) | 102 (12.8) | 104 (9.1) |
| B | 114 (10.2) | 98 (15.9) | 105 (9.6) | 112 (12.3) | 105 (10.7) | 107 (8.1) |
| C | 112 (9.7) | 100 (15.9) | 107 (10.1) | 113 (12.5) | 106 (10.4) | 108 (8.5) |
| D | 112 (10.1) | 102 (16.3) | 107 (10.3) | 115 (12.7) | 107 (10.6) | 109 (9.0) |
| E | 113 (10.3) | 105 (16.4) | 108 (10.3) | 117 (11.6) | 107 (9.7) | 110 (8.5) |
| 0.5 | <0.0001 | <0.001 | <0.0001 | <0.0001 | <0.0001 | |