From The Ergoweb® Learning Center

RESEARCH: Aging Employees Unfettered By Overtime Work Demands

Older employees tended to have more physical limitations and poorer health compared to younger employees but were able to work overtime without experiencing greater adverse health, productivity, or safety outcomes, according to a study involving 2,746 industrial workers.  Further, older employees had less productivity loss when working overtime relative to their younger cohorts.

These findings became slightly altered among a small subgroup of workers. For four of the nine undesirable health, productivity, and safety outcomes, an association was found between hourly employees working extended overtime (60 + hours/week) and increasing age. When considering moderate overtime (48.01 to 59.99 hours) and the impact of prior disability among hourly employees, increasing age had little association with these measurements.  
For salaried employees, there was no association between overtime and adverse outcomes as age increased.
The Bottom Line – How This Applies To Ergonomists
In general, overtime work performed by older workers does not lead to greater business costs.  However, increasing worker age can be a concern among hourly workers who perform extended overtime.  An ergonomist should be on the lookout for this specific risk factor combination and recommend appropriate controls. 

Study Design
Volunteers were drawn from six plants owned by one heavy manufacturing company.  Table 1 presents the study’s age/subject representation.


Number of study subjects

≤ 29


30 – 34


35 – 39


40 – 44


45 – 49


50 – 54


55 – 59


60 – 64


≥ 65

Table 1: Study age stratification

Average workhours per week were categorized as < 40 hours, 40 – 48 hours, 48.01-59.99 hours, and 60+ hours.  Descriptive controls were established for percent male, hourly workers, exempt workers, skilled job, production job, and company tenure. As age increased, percent male and percent hourly increased while percent exempt decreased. The length of the workweek was significantly greater in the older age groups.

Employee clinical status was not an exclusion factor for this study.

For each subject, the average hours worked per week during April to June 2001, was categorized into <40, 40 to 48.0, 48.01 to 59.99, and 60+. In analysis of data, the volunteers were grouped into ages of < 45, 45 – 49, and >49.

An initial data collection survey was conducted during May 2001, with a follow up in September 2001. Three health measures (diseases, physical, and mental health during the prior four weeks) were assessed at each session.  Productivity was evaluated through overall work effectiveness and capacity. Workers compensation and disability databases were reviewed in April 2002 to identify work injuries.

Study Limitations
1) This was a retrospective analysis instead of a prospective study.
2) This analysis was part of a larger study and was not initiated with a focus on the relationship between age and overtime work.
3) There was a relatively short exposure time period from which this study drew its data.  

Article Title: Age, Overtime, and Employee Health, Safety and Productivity Outcomes: A Case Study

Publication: Journal of Occupational and Environmental Medicine, 50, 873-894, 2008

Authors: H Allen, C Woock, L Barrington, and W Bunn

This article originally appeared in The Ergonomics Report™ on 2008-10-22.