*Oregon Health & Science University, Portland, OR

†Department of Epidemiology, University of Washington, Seattle, WA

‡Mongan Institute Health Policy Research Center, Massachusetts General Hospital

§Department of Medicine, Harvard Medical School, Boston, MA

J.D.’s time for this publication was supported by the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health (K12HD043488).

The authors declare no conflict of interest.

Correspondence to: Kendall A. Lawley, MS, Department of Epidemiology, University of Washington, 1400 NE Campus Parkway, Seattle, WA 98195. E-mail: [email protected].