Prevalence, incidence, and recurrence of low back pain in scaffolders during a 3-year follow-up study.

STUDY DESIGN Prospective cohort study. OBJECTIVE To describe the natural history of low back pain by its prevalence, incidence, and recurrence during a 3-year period and identify risk factors for cumulative incidence and recurrence of low back pain in scaffolders. SUMMARY OF BACKGROUND DATA Although some studies have described prevalence, incidence, or recurrence of low back pain, few studies have assessed two or more of these outcome measures simultaneously. Furthermore, little is known about the association between individual, physical, psychosocial, and health-related risk factors and cumulative incidence and recurrence of low back pain in scaffolders. METHODS Between 1998 and 2001, a cohort of 288 scaffolders (response 85%) completed a questionnaire at baseline and at three yearly follow-ups during 3 years. RESULTS At baseline 60% of the study population had had an episode of low back pain in the past 12 months of which 22% was of chronic nature. During follow-up, the yearly incidence of low back pain varied between 20% and 28%, while yearly recurrence rates were 64% to 77%. Only few workers consistently reported the presence (20%) or absence (26%) of low back pain each year. Weak significant associations were present for the following: age 35 to 44 years, moderate general health, high strenuous arm movements, and body mass index with the cumulative incidence of low back pain. Significant associations were found between high manual handling of material and high job demand and low job control and the cumulative recurrence of low back pain, while moderate general health only showed a weak significant association with this outcome measure. CONCLUSIONS Low back pain was a dynamic process with high rates for incidence, recurrence, and recovery. General health and work-related physical and psychosocial factors influenced both the incidence and recurrence of low back pain. The incidence and recurrence of low back pain depend strongly on the recall period of low back pain and the time-window of investigation.