About the Authors

Dustin T. Duncan

Dustin.Duncan@nyumc.org

Affiliations Department of Population Health, New York University School of Medicine, New York, NY, United States of America, College of Global Public Health, New York University, New York, NY, United States of America, Population Center, New York University, New York, NY, United States of America, Center for Health, Identity, Behavior and Prevention Studies, New York University, New York, NY, United States of America, Center for Drug Use and HIV Research, New York University College of Nursing, New York, NY, United States of America, Center for Data Science, New York University, New York, NY, United States of America

Farzana Kapadia

Affiliations Department of Population Health, New York University School of Medicine, New York, NY, United States of America, College of Global Public Health, New York University, New York, NY, United States of America, Population Center, New York University, New York, NY, United States of America, Center for Health, Identity, Behavior and Prevention Studies, New York University, New York, NY, United States of America, Center for Drug Use and HIV Research, New York University College of Nursing, New York, NY, United States of America

Seann D. Regan

Affiliation Department of Population Health, New York University School of Medicine, New York, NY, United States of America

William C. Goedel

Affiliations Department of Population Health, New York University School of Medicine, New York, NY, United States of America, College of Global Public Health, New York University, New York, NY, United States of America

Michael D. Levy

Affiliation Center for Health, Identity, Behavior and Prevention Studies, New York University, New York, NY, United States of America

Staci C. Barton

Affiliation Center for Health, Identity, Behavior and Prevention Studies, New York University, New York, NY, United States of America

Samuel R. Friedman

Affiliations Center for Drug Use and HIV Research, New York University College of Nursing, New York, NY, United States of America, Institute of Infectious Disease Research, National Development and Research Institutes, Inc., New York, NY, United States of America

Perry N. Halkitis

Affiliations Department of Population Health, New York University School of Medicine, New York, NY, United States of America, College of Global Public Health, New York University, New York, NY, United States of America, Population Center, New York University, New York, NY, United States of America, Center for Health, Identity, Behavior and Prevention Studies, New York University, New York, NY, United States of America, Center for Drug Use and HIV Research, New York University College of Nursing, New York, NY, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: DTD FK. Analyzed the data: DTD SDR. Wrote the paper: DTD WCG. Obtained the funding: DTD FK. Made the figure: SDR. Led the GPS training of research staff: WCG. Verified the GPS travel diary data: WCG. Formatted the references: WCG. Recruited participants: MDL SCB. Collaborated on the funded proposal: SRF PNH. Principal investigator of the parent study: PNH. Read and approved the final version of the manuscript: DTD FK SDR WCG MDL SCB SRF PNH.