For each child, we determined whether the ratio of observed to predicted Characteristics of the Study Participants There were slightly more girls than boys (52% vs. 48%) in each of the three cohorts (Table S1 in the Supplementary Appendix)
For each child, we determinedwhether the ratio of observed to predictedCharacteristics of the Study ParticipantsThere were slightly more girls than boys (52%vs. 48%) in each of the three cohorts (Table S1 inthe Supplementary Appendix)