Published on in Vol 7, No 1 (2019): January
![How Well iPhones Measure Steps in Free-Living Conditions: Cross-Sectional Validation Study How Well iPhones Measure Steps in Free-Living Conditions: Cross-Sectional Validation Study](https://asset.jmir.pub/assets/07266ce04b2c9f1384f1bc4dc0b15607.png 480w,https://asset.jmir.pub/assets/07266ce04b2c9f1384f1bc4dc0b15607.png 960w,https://asset.jmir.pub/assets/07266ce04b2c9f1384f1bc4dc0b15607.png 1920w,https://asset.jmir.pub/assets/07266ce04b2c9f1384f1bc4dc0b15607.png 2500w)
1 Department of Preventive Medicine and Public Health, Tokyo Medical University, Shinjuku-ku, Japan
2 Department of Social and Behavioral Sciences, Harvard TH Chan School of Public Health, Boston, MA, United States
3 Department of Health Sociology and Health Education, School of Public Health, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan
4 Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Japan
5 Division of Preventive Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
6 Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, United States