Study design: Cross-sectional with follow-up case-control component.
Objectives: To measure the prevalence of back pain (BP) and back pain exacerbations, describe BP features and functional impairment, estimate BP-related lost productive time (LPT) and costs, and assess the relation between pain exacerbations and lost productive time.
Summary of background data: BP is associated with substantial lost work time. However, little is known about the extent to which BP with or without exacerbation explains lost work time.
Methods: A national telephone survey of the U.S. workforce identified 320 workers 40 to 65 years of age with BP defined by NHANES I criteria and 91 matched non-BP controls. Participants self-reported pain characteristics, lost productive time (absenteeism and presenteeism) in the previous 2 weeks, activity limitations, and demographics. A population-weighting adjustment was applied to estimates to account for selection bias and ensure that estimates of certain sample demographic subgroups' totals conformed to the Current Population Survey.
Results: The 2-week period prevalence of BP was 15.1%; 42% of workers with BP experienced pain exacerbations. BP prevalence was associated with demographic factors, but BP exacerbations were not. BP was reported by 42.6% of all workers. Workers with exacerbations reported more days with BP than those without exacerbations. Workers with exacerbations were significantly more likely than those without such exacerbations to report activity limitation (88.4% vs. 60.7%; P < 0.0001) and BP-related LPT (22.1% vs. 13.0%; P = 0.0259). BP in workers 40 to 65 years of age costs employers an estimated $7.4 billion/year. Workers with BP exacerbations account for 71.6% of this cost.
Conclusions: Workers with BP exacerbations account for a disproportionate share of the cost of BP-related lost productive time.