The March of Dimes disparity ratio measures and tracks progress towards the elimination of racial/ethnic disparities in
preterm birth. It’s based on Healthy People 2020 methodology and compares the group with the lowest preterm birth
rate to the average for all other groups. Progress is evaluated by comparing the current disparity ratio to a baseline
disparity ratio. A lower disparity ratio is better, with a disparity ratio of 1 indicating no disparity.