First-Born vs Second-Born: 10-Million-Sibling Study Maps 150 Disease Risk Differences

First-Born vs Second-Born: 10-Million-Sibling Study Maps 150 Disease Risk Differences

A massive study of health records from more than 10 million American siblings suggests that birth order may be associated with the risk of developing certain diseases and medical conditions later in life. Researchers from the University of Chicago and Columbia University analyzed two decades of U.S. health insurance data on more than 10.3 million children with one sibling. The study examined 569 disease categories and found statistically signifi…