[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
Views 154
Citations 0
Comment & Response
November 2019

Age-Related Bias in Total Step Count Recorded By Wearable Devices—Reply

Author Affiliations
  • 1Division of Preventive Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
  • 2Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
  • 3Laboratory of Epidemiology and Population Science, National Institute on Aging, Baltimore, Maryland
JAMA Intern Med. 2019;179(11):1603. doi:10.1001/jamainternmed.2019.4691

In Reply We thank Kuo and colleagues for their letter regarding our Original Investigation1 and agree that physical inactivity is a major public health problem in the United States and worldwide, which contributes to much ill health.2 Our main goal in conducting a study of step volume and intensity and their association with all-cause mortality was to provide information potentially useful for future physical activity guidelines.3 Current guidelines1 are couched in terms of recommended time spent in physical activity of moderate-to-vigorous intensity. This can be easily gauged by persons who purposefully exercise or walk for transportation; however, for those who may be active in their daily life (eg, someone who might actively play with children or grandchildren, or walk to the store to buy a replacement light bulb) but who do not intentionally exercise, it can be challenging to assess whether they are active enough to fulfill recommendations. Step counts may thus be a useful alternate metric, given the current ubiquity of step counters. Prior to our study, a widespread belief was that one needed 10 000 steps/d to achieve health benefit, which can be discouraging to inactive persons. Our findings indicated that 10 000 steps/d was not needed for lower mortality rates among older women who were not particularly active (mean step count of approximately 5500 steps/d).

Limit 200 characters
Limit 25 characters
Conflicts of Interest Disclosure

Identify all potential conflicts of interest that might be relevant to your comment.

Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.

Err on the side of full disclosure.

If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.

Not all submitted comments are published. Please see our commenting policy for details.

Limit 140 characters
Limit 3600 characters or approximately 600 words