Fig. 2

Predicted probability of neurodevelopmental delay according to socioeconomic backgrounds. This figure shows that in the 2nd check-up, there was no difference in neurodevelopmental delay between the low- and high-SES groups; however, a significant difference emerged from the 3rd check-up and continued to grow until the 7th check-up (time estimate, 0.0867; interaction P < 0.001). Blue, low SES; Red, intermediate SES; Green, high SES. SES, socioeconomic status