Table 1.

Demographic and clinical characteristics of participants

Characteristics	LDE group (n = 81)	HDE group (n = 68)	t/x2	P
Age, months(mean ± SD)	40.06 ± 11.45	36.40 ± 9.72	2.07	0.04
Sex, male (%)	71.3	68.7	0.11	0.73
Preterm birth(%)	8.8	4.4	1.09	0.29
Annual income (10,000 yuan)(%)			5.04	0.08
0–5	20.0	35.3
5–10	58.8	42.6
> 10	21.3	22.1
Mean ST (min/day) (mean ± SD)	24.67 ± 17.41	181.93 ± 99.91	12.81	<0.001
Total CARS scores(mean ± SD)	34.72 ± 4.00	35.75 ± 3.08	1.71	0.08
Griffiths (DQ)
Locomotor(mean ± SD)	69.07 ± 14.69	70.80 ± 13.85	0.73	0.46
Personal − social(mean ± SD)	52.02 ± 16.05	49.75 ± 16.18	0.85	0.39
Hearing and language(mean ± SD)	42.09 ± 19.64	35.54 ± 14.92	2.31	0.02
Eye − hand coordination(mean ± SD)	54.49 ± 17.75	53.82 ± 16.30	0.23	0.81
Performance(mean ± SD)	57.96 ± 19.25	61.47 ± 21.33	1.05	0.29

LDE low-dose exposure, HDE high-dose exposure, ST screen time, CARS childhood autism rating scale, DQ developmental quotient