Potential risk factors of persistent low back pain developing from mild low back pain in urban Japanese workers.
METHODS
Two-year, prospective cohort data from the Japan epidemiological research of occupation-related back pain study in urban settings were used for this analysis.


OBJECTIVE
To examine the association between aggravated low back pain and psychosocial factors among Japanese workers with mild low back pain.


BACKGROUND
Although psychosocial factors are strongly indicated as yellow flags of low back pain (LBP) leading to disability, the association between aggravated LBP and psychosocial factors has not been well assessed in Japanese workers.


METHODS
At baseline, 5,310 participants responded to a self-administered questionnaire including questions about individual characteristics, ergonomic work demands, and work-related psychosocial factors (response rate: 86.5%), with 3,811 respondents completing the 1-year follow-up questionnaire. The target outcome was aggravation of mild LBP into persistent LBP during the follow-up period. Incidence was calculated for the participants with mild LBP during the past year at baseline. Logistic regression was used to explore risk factors associated with persistent LBP.


RESULTS
Of 1,675 participants who had mild LBP during the preceding year, 43 (2.6%) developed persistent LBP during the follow-up year. Multivariate analyses adjusted for individual factors and an ergonomic factor found statistically significant or almost significant associations of the following psychosocial factors with persistent LBP: interpersonal stress at work [adjusted odds ratio (OR): 1.96 and 95% confidence interval (95%CI): 1.00-3.82], job satisfaction (OR: 2.34, 95%CI: 1.21-4.54), depression (OR: 1.92, 95%CI: 1.00-3.69), somatic symptoms (OR: 2.78, 95%CI: 1.44-5.40), support from supervisors (OR: 2.01, 95%CI: 1.05-3.85), previous sick-leave due to LBP (OR: 1.94, 95%CI: 0.98-3.86) and family history of LBP with disability (OR: 1.98, 95%CI: 1.04-3.78).


CONCLUSIONS
Psychosocial factors are important risk factors for persistent LBP in urban Japanese workers. It may be necessary to take psychosocial factors into account, along with physical work demands, to reduce LBP related disability.
Clinical Research Center for Occupational Musculoskeletal Disorders, Kanto Rosai Hospital, Kawasaki, Kanagawa, Japan.
Ko
K
Matsudaira
Department of Orthopaedic Surgery, Nagasaki Rosai Hospital, Sasebo, Nagasaki, Japan.
Hiroaki
H
Konishi
Spine Center, Yokohama Rosai Hospital, Yokohama, Kanagawa, Japan.
Kota
K
Miyoshi
Clinical Research Department, CLINICAL STUDY SUPPORT, Inc., Nagoya, Aichi, Japan.
Tatsuya
T
Isomura
Clinical Research Department, CLINICAL STUDY SUPPORT, Inc., Nagoya, Aichi, Japan.
Kyoko
K
Inuzuka
D000328:Adult; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis* / Q000453:epidemiology; D016272:Occupational Health / Q000706:statistics & numerical data; D010147:Pain Measurement; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014505:Urban Population; D014937:Work