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

Table 2 Summary of meta-analysis results of the influence of premature delivery and mother’s education level on attention deficit hyperactivity disorder

Intervention measure	Item	Z	OR	95%CI	P value	I2
Premature	Premature vs term	21.13	2.76	2.52-3.04	< 0.001	1.9%
	Very premature vs mild-late premature	3.66	1.95	1.37-2.79	< 0.001	87.3%
Education level of mother	≥ 12 years vs < 12 years	1.56	0.78	0.57-1.07	0.119	91.7%
	≥ 12 years vs < 9 years	2.19	0.61	0.39-0.95	0.029	84.5%
	≥ 12 years vs < 9 years1	4.98	0.59	0.48-0.73	< 0.001	47.1%
	≥ 12 years vs 9-12 years	2.40	0.74	0.58-0.95	0.016	77.6%
	9-12 years vs < 9 years	1.44	0.74	0.49-1.11	0.150	59.2%

¹Eliminate the literature with great heterogeneity.

OR: Odds ratio; CI: Confidence interval.