Table 4.
Subgroup analysis of the randomized controlled trials
| Subgroup | Number of studies (n) | RR (95% CI) | I2 (%) | P overall effect | P interaction |
|---|---|---|---|---|---|
| Region | 0.87 (0.72, 1.06) | 53 | 0.17 | 0.06 | |
| Oceania | 2 | 0.96 (0.75, 1.22) | 8 | 0.72 | |
| Europe | 5 | 0.76 (0.60, 0.96) | 57 | 0.02 | |
| North America | 1 | 1.58 (0.88, 2.82) | 36 | 0.13 | |
| EPA/DHA | 0.87 (0.72, 1.06) | 53 | 0.17 | 0.48 | |
| EPA/DHA ≥ 1 | 4 | 0.83 (0.63, 1.09) | 66 | 0.19 | |
| EPA/DHA < 1 | 5 | 0.96 (0.72, 1.28) | 23 | 0.77 | |
| Follow-up duration | 0.87 (0.72, 1.06) | 53 | 0.17 | 0.36 | |
| Infancy | 2 | 0.75 (0.47, 1.35) | 0 | 0.33 | |
| Toddlerhood | 2 | 0.56 (0.27, 1.17) | 53 | 0.12 | |
| Preschool age and above | 4 | 0.93 (0.75, 1.16) | 58 | 0.54 | |
| Intervention initiation time | 0.87 (0.72, 1.06) | 53 | 0.17 | 0.08 | |
| <20 weeks | 2 | 1.33 (0.78, 2.27) | 48 | 0.29 | |
| ≥20 weeks | 6 | 0.80 (0.65, 0.98) | 57 | 0.03 | |
| Disease type | 0.92 (0.77, 1.10) | 43 | 0.36 | 0.20 | |
| Asthma | 7 | 0.80 (0.61, 1.05) | 28 | 0.11 | |
| Eczema | 7 | 1.21 (0.87, 1.67) | 53 | 0.26 | |
| Food allergy | 4 | 0.75 (0.40, 1.41) | 23 | 0.37 | |
| Rhinoconjunctivitis | 4 | 0.83 (0.66, 1.03) | 0 | 0.09 | |
| Types of food allergies | 0.47 (0.30, 0.76) | 0 | 0.002 | 0.98 | |
| Egg allergy | 3 | 0.47 (0.28, 0.80) | 0 | 0.006 | |
| Cow’s milk allergy | 2 | 0.43 (0.11, 1.79) | 0 | 0.25 | |
| Peanut allergy | 1 | 0.53 (0.14, 1.95) | – | 0.34 |