Impact of repetitive manual materials handling and psychosocial work factors on the future prevalence of chronic low-back pain among construction workers

OBJECTIVES: This study investigated the influence of manual stone and brick handling and psychosocial work factors on the risk of chronic low-back pain and describes the impact in terms of risk advancement period. METHODS: The Hamburg Construction Worker Study included a longitudinal study among 488 male construction workers. Adjusted prevalence ratios (PR) of chronic low-back pain (>3 months during the last 12 months) according to self-reported worktasks in the baseline survey were estimated with the Cox proportional hazards model. RESULTS: The 1-year prevalence of chronic low-back pain was 15.4%. Workers with chronic low-back pain in the baseline survey had a higher risk of such pain during the follow-up (PR4.07,95% CI 2.18-7.59). The prevalence in association with laying large lime sandstones for >2 hours per shift (PR 1.80, 95% CI 1.04-3.14) further increased after adjustment for job category (PR 2.69, 95% CI 1.25-5.78), and it advanced the risk by a risk advancement period of 18 years (95% CI 4-39). Workers with low satisfaction with their work achievements had a higher prevalence of chronic low-back pain (PR 2.07, 95% CI 1.10-3.88). Similar risk estimates were observed in the subgroup without chronic low-back pain in the baseline survey. A strong effect of time pressure wasonly present for these workers (high: P R 6.30,95% CI 1.41-28.21). CONCLUSIONS: The results suggest that repetitive work involving bent positions and the manual manipulation of heavy stones increases the risk of future chronic low-back pain. For risk communication, the notion that a 40-year-old construction worker laying large sandstones has the same risk as an unexposed 58-year-old construction worker may be more informative.