Reducing bias: accounting for the order of co-first authors.

Reflecting an increasing emphasis on collaborative science, the number of authors on published articles has markedly risen with time. With this trend, we see an increase in papers designating 2 or more co-first authors. To improve transparency in how such designations are made and reduce bias in the assignment of order, the JCI is now requiring an explanation for how the first-author position is determined when shared among contributing authors.