Related Experiment Video
Updated: Apr 28, 2026

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
Differences in time use and activity patterns when adding a second job: implications for health and safety in the
Helen R Marucci-Wellman1, Tin-Chi Lin, Joanna L Willetts
1The authors are with Center for Injury Epidemiology, Liberty Mutual Research Institute for Safety, Hopkinton, MA.
Objectives:
We compared work and lifestyle activities for workers who work in 1 job with those who work in multiple jobs during a 1-week period.
Methods:
We used information from the 2003-2011 American Time Use Survey to classify workers into 6 work groups based on whether they were a single (SJH) or multiple (MJH) job holder and whether they worked their primary, other, multiple, or no job on the diary day.
Results:
The MJHs often worked 2 part-time jobs (20%), long weekly hours (27% worked 60+ hours), and on weekends. The MJHs working multiple jobs on the diary day averaged more than 2 additional work hours (2.25 weekday, 2.75 weekend day; P < .05), odd hours (more often between 5 pm and 7 am), with more work travel time (10 minutes weekday, 9 minutes weekend day; P < .05) and less sleep (-45 minutes weekday, -62 minutes weekend day; P < .05) and time for other household (P < .05) and leisure (P < .05) activities than SJHs.
Conclusions:
Because of long work hours, long daily commutes, multiple shifts, and less sleep and leisure time, MJHs may be at heightened risk of fatigue and injury.
Related Concept Videos
The Availability Heuristic
Methods of Documentation II: POMR
Social Traps
Quantifying Work
Insufficient Sleep and Sleep Deprivation
Sleep deprivation is a more severe form of sleep loss...
Substance Use Disorders Affecting Sleep
Understanding the concepts of physical dependence,...

