Table 2 Demographic characteristics after propensity score matching

Gender

 >0 .999^a

 Female

30,115 (60.16)

30,115 (60.16)

 Male

19,945 (39.84)

19,945 (39.84)

Age^c

 >0 .999^b

 Mean ± SD

3.26 + 2.31

3.26 + 2.31

Economic status

 > 0.999^a

 Low income

3543 (7.08)

3543 (7.08)

Confounders

 Blindness and low vision

3 (0.01)

3 (0.01)

 >0 .999^a

 Epilepsy

180 (0.36)

180 (0.36)

 >0 .999^a

 Fetal and neonatal hemorrhage

12 (0.02)

12 (0.02)

 >0 .999^a

 Communicating hydrocephalus

4 (0.01)

4 (0.01)

 >0 .999^a

 Intrauterine hypoxia and birth asphyxia

15 (0.03)

15 (0.03)

 >0 .999^a

 Other perinatal jaundice

37 (0.07)

37 (0.07)

 >0 .999^a

 Microcephalus

12 (0.02)

12 (0.02)

 > 0.999^a

 Patent ductus arteriosus

363 (0.73)

363 (0.73)

 >0 .999^a

 Pneumonia

1592 (3.18)

1592 (3.18)

 > 0.999^a

 Pneumothorax

3 (0.01)

3 (0.01)

 > 0.999^a

 Other respiratory conditions of fetus and newborn

217 (0.43)

217 (0.43)

 > 0.999^a