Variables | MLBW (n = 50,060) | No MLBW (n = 50,060) | p value |
---|---|---|---|
Gender |  >0 .999a | ||
 Female | 30,115 (60.16) | 30,115 (60.16) |  |
 Male | 19,945 (39.84) | 19,945 (39.84) |  |
Agec |  >0 .999b | ||
 Mean ± SD | 3.26 + 2.31 | 3.26 + 2.31 |  |
Economic status |  > 0.999a | ||
 Low income | 3543 (7.08) | 3543 (7.08) |  |
Confounders | |||
 Blindness and low vision | 3 (0.01) | 3 (0.01) |  >0 .999a |
 Epilepsy | 180 (0.36) | 180 (0.36) |  >0 .999a |
 Fetal and neonatal hemorrhage | 12 (0.02) | 12 (0.02) |  >0 .999a |
 Communicating hydrocephalus | 4 (0.01) | 4 (0.01) |  >0 .999a |
 Intrauterine hypoxia and birth asphyxia | 15 (0.03) | 15 (0.03) |  >0 .999a |
 Other perinatal jaundice | 37 (0.07) | 37 (0.07) |  >0 .999a |
 Microcephalus | 12 (0.02) | 12 (0.02) |  > 0.999a |
 Patent ductus arteriosus | 363 (0.73) | 363 (0.73) |  >0 .999a |
 Pneumonia | 1592 (3.18) | 1592 (3.18) |  > 0.999a |
 Pneumothorax | 3 (0.01) | 3 (0.01) |  > 0.999a |
 Other respiratory conditions of fetus and newborn | 217 (0.43) | 217 (0.43) |  > 0.999a |