Persistence of low back pain reporting among a cohort of employees in a metal corporation: a study with 5-, 10-, and 28-year follow-ups.

Low back pain (LBP) is a common symptom among adults but little is known about its persistence over time in defined populations. The aim of this study was to examine the persistence of LBP among a cohort of industrial employees studied in four successive surveys during a total of 28 years. Cross-tabulations and logistic regression was used to estimate the interdependence of LBP occurrence at the surveys. At baseline, 54% of the subjects reported local LBP and 25% LBP radiating to the lower limb(s). Persistent or recurrent LBP was common. Of those with LBP at baseline, 75, 73, and 88% reported it also at the 5-, 10- or 28-year follow-up, respectively. Of those with radiating pain, 66, 65, and 69% were symptomatic 5, 10, or 28 years later. The onset of reporting LBP increased during follow-up. Of those without local LBP at baseline, 33, 37 and 64% had pain at the 5-, 10-, or 28-year follow-up, respectively. Of those without radiating LBP, 17, 22, and 46% had pain at the 5-, 10-, or 28-year follow-up. The odds ratio of local LBP at the 5-, 10-, or 28-year follow-up for those with such pain at baseline vs. not were 6.0 (95% CI 4.3-8.3), 4.7 (3.3-6.6) and 4.0 (2.6-6.3), adjusted for age, gender and occupational class. The respective figures for radiating LBP were 8.5 (5.7-12.5), 6.7 (4.4-10.1) and 2.3 (1.5-3.6). We conclude that LBP is commonly recurrent.