Association of premature birth and maternal education level on attention deficit hyperactivity disorder in children: A meta-analysis

Figure 3 Meta-analysis forest map of mothers with different years of education. A: ≥ 12 years vs 12 years; B: ≥ 12 years vs 9 years; C: ≥ 12 years vs 9 years; D: ≥ 12 years vs 9-12 years; E: 9-12 years vs < 9 years. After the adjustment of meta-analysis, the studies with large heterogeneity were manually excluded. OR: Odds ratio; CI: Confidence interval.