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Physical and Psychosocial Factors Associated with Duration of Lost Work Time

Workers off the job for more than four weeks due to injury/illness were more likely to have tasks characterized by low meaning of work, stooping work positions, back twisting, lifting more than 30 kg, and repetitive activities according to a prospective Danish study of 428 stricken employees.  Being off work for up to one year was related to workers whose tasks involved stooping work positions and repetitive activity.  Low skill discretion, low meaning of work, lifting more than 30 kg, and pushing/pulling were job qualities predictive of worker sickness absence of greater than one year.

Labriola et al. identified subjects who had injury/illness time loss of at least two weeks from among three employers (major pharmaceutical company, municipal workplaces in the care sector, and municipality services).  Members of this cohort group were followed for one year after onset of lost work time and placed within one of three groups: return to work within four weeks of the onset of sickness absence; return to work within one year of onset of sickness absence; or, sickness absence continued for more than one year.

Via a questionnaire, the subjects assessed physical workplace factors of their jobs on a gradient from “never” to “almost all the time” for daily exposure to:

  • stooping work position

  • twisting the back

  • lifting more than 30 kg

  • pushing/pulling heavy burdens

  • full body vibration

  • repeating the same job task many times per hour

The workers also evaluated several workplace psychosocial factors including:

  • psychologic demands

  • decision authority

  • skill discretion

  • co-worker social support

  • meaning of work

  • predictability of work

  • management quality

Workplace size was categorized as small (under 50 employees) or large (over 50 employees).  Controls were established for gender, age, smoking status, alcohol consumption, body mass index, general health, and family status.


The study revealed that exposure to physical work factors had a stronger association with prolonged lost work time than psychosocial exposures. Labriola et al. note sample basis may have influenced this finding since most of the study workers held blue collar jobs.   It was also shown that the longer the lost time duration, the lower the strength of relationship with work environmental factors (both physical and psychosocial).   This suggests, according to the authors, that personal issues such as family status and personal health may become more significant as the duration of lost time increases.

Fifty-one percent of the workers who experienced sickness absence returned to work within four weeks while 85.7 percent returned to work within one year.  There was no significant relationship found between company size and duration of sickness absence.

Article Title: Multilevel Analysis of Individual and Contextual Factors as Predictors of Return to Work

Publication: Journal of Occupational and Environmental Medicine 48: 1181-1188, 2006

Authors: M Labriola, T Lund, K B Christensen, and T S Kristensen

This article originally appeared in The Ergonomics Report™ on 2007-01-31.