Built-in Healthcare Applications Reveal Step Changes Associated with Temperature, Transportation, and Marital Status Among Urban Cities in Japan

BACKGROUND Walking is a fundamental daily activity representing health status and physical condition. The number of steps taken in a given time period is widely used in research areas such as aging, geriatrics, gerontology, public health, and preventive medicine. However, the underlying mechanisms of step counts are not well understood.

To investigate daily step counts associated with temperature, transportation, and marital status. DESIGN Time series analysis of daily steps using built-in healthcare applications on smartphones. SETTING Government-designated, well-developed urban cities in Japan: Fukuoka, Kawasaki, Kobe, Kyoto, and Saitama. PARTICIPANTS Respondents totaled 622 40- to 79-year-olds, comprising 370 males and 252 females. MEASUREMENTS The mean period of our retrospective data was 2,344 days.

Seasonal-trend decomposition using loess was applied to time series steps. With the high coefficient of determination R2: 0.798, an absolute value function was fitted between temperature and the mean daily steps of the seasonal component. Furthermore, ordinary train usage in Saitama, Kawasaki, and Fukuoka was significantly greater than that in Kobe and Kyoto by 14.1 points (p = 0.001). Moreover, married and divorced or bereaved males’ mean daily step counts were significantly larger than those of females’ by 1,832 (p = 0.001) and 2,480 (p = 0.001), respectively. By contrast, the difference in the mean daily step counts for unmarried males and females was only 100.

This study presents significant associations between mean daily steps and the factors of temperature, transportation, and marital status. These associations can alleviate biases in step research by area and season to facilitate better step count comparisons in many research fields. Competing Interest Statement The authors have declared no competing interest. Funding Statement This research received no external funding. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The director of the Digital Transformation & Cyber-Physical Systems Division, Panasonic Holdings Corporation gave ethical approval for this work. The smartphone data used in our study had been de-identified prior to its use in this study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability Not applicable.