Table 1.
Characteristics of the sample
| Total sample N = 1522 |
Complete cases N = 945* |
Incomplete cases N = 577 |
Significance (complete v incomplete cases)** | |
|---|---|---|---|---|
| Age (years) | Difference (95% CI) | |||
| Mean (SD) | 30.5 (5.5) | 30.4 (5.5) | 30.4 (5.5) | − 0.2 (− 0.4,0.7) |
| Missing n (%) | 1 (0.1) | p = 0.60 | ||
| BMI (kg/m2) | Z: 0.22 | |||
| Median (IQR) | 34.6 (32.3–38.1) | 34.5 (32.3–38.0) | 34.7 (32.2–38.4) | p = 0.83 |
| Missing n (%) | 13 (0.9) | |||
| Index of multiple deprivation quintiles | Chi square: 5.45 | |||
| n (%) | p = 0.24 | |||
| 1 (least deprived) | 62 (4.1) | 40 (4.2) | 22 (3.9) | |
| 2 | 100 (6.6) | 60 (6.4) | 40 (7.0) | |
| 3 | 173 (11.4) | 119 (12.6) | 54 (9.5) | |
| 4 | 523 (34.4) | 311 (32.9) | 212 (37.2) | |
| 5 (most deprived) | 657 (43.2) | 415 (43.9) | 242 (42.5) | |
| Missing | 7 (0.5) | |||
| Ethnicity n(%) | Chi square: 19.25 | |||
| Asian | 91 (6) | 62 (6.6) | 29 (5.0) | p < 0.01 |
| Black | 391 (25.7) | 207 (21.9) | 184 (31.9) | |
| White | 955 (62.8) | 622 (65.8) | 333 (57.8) | |
| Other | 84 (5.5) | 54 (5.7) | 30 (5.2) | |
| Missing | 1 (0.1) | |||
| Intervention n(%) | Chi square: 0.74 | |||
| Yes | 768 (50.5) | 485 (51.3) | 283 (49.1) | p = 0.39 |
| No | 754 (49.5) | 460 (48.7) | 294 (50.9) | |
| Missing | 0 (0) | |||
| Baseline EPDS ≥ 13 n (%) | Chi square: 2.64 | |||
| ≥ 13 | 163 (10.7) | 107 (11.3) | 56 (14.6) | p = 0.10 |
| < 13 | 1167 (76.7) | 838 (88.7) | 329 (85.4) | |
| Missing | 192 (12.6) | |||
| Baseline EPDS depression score (/30) | Z: 0.87 | |||
| Median (IQR) | 6 (3–10) | 6 (3–10) | 6 (3–10) | p = 0.38 |
| Missing n (%) | 192 (12.6) | |||
| Baseline MET (mins/week) | Difference (95% CI) | |||
| Median (IQR) | 3383.3 (4960.2) | 1434 (693–3744) | 1386 (522–3177) | − 16.3 (-63.6, − 0.01) |
| Square root transformed mean (SD) | 47.7 (33.3) | 48.9 (33.8) | 44.8 (31.9) | p = 0.04 |
| Missing n (%) | 191 (12.5) | |||
| Glycaemic load (grams/day) | Difference (95% CI) | |||
| Mean (SD) baseline | 136.7 (52.6) | 136.5 (51.4) | 138.1 (59.0) | 1.7 (-6.9,10.2) |
| Missing n (%) | 403 (26.5) | p = 0.70 | ||
| Saturated fat (% energy) | Difference (95% CI) | |||
| Mean (SD) baseline | 12.6 (3.0) | 12.6 (3.0) | 12.7 (2.9) | 0.1 (− 0.3,0.6) |
| Missing n (%) | 403 (26.5) | p = 0.56 |
* Complete baseline EPDS, glycaemic load, saturated fat and physical activity (MET) and complete covariate data
**Chi square for categorical variables, t test for parametric continuous variables and Mann Whitney for non-parametric continuous variables