Attributions, Stress, and Work-Related Low Back Pain

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Attributions, Stress, and Work-Related Low Back
Pain

• George Byrns, MPH, Ph.D., CIH
• Illinois State University

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Background Significance

• LBP WC claims in the US (1992)
• 16 of claims
• 33 of costs (gt49 billion)
• Risk factors
• individual, job-related, physical, psychosocial
• In spite of mechanization, LBP is still a major
  source of disability

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Physical Stain Model
Exposure
Capacity
Dose
Response
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Conceptual Model for Attributions as a Risk
Factor for LBP
W o r k E n v I r o n m e n t
Physical demand
Low Back Pain Function Injury
Attributions
Resources
Knowledge of Back Safety
Psychological demand
Psychological Stress
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The Dimensions of Resources
R e s o u r c e s
Individual characteristics
Age Gender Fitness Body mass index
Education Coping skills Smoking Prior LBP
Social environment
Job social support Home social support
Safety climate
Management support Implementation
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What is an attribution?

• Attribution a natural human tendency to see
  patterns or explain unfortunate events
• Attributions have 3 major dimensions
• locus of causation
• stability/permanence
• controllability

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How are attributions stress related?

• External, permanent, uncontrollable factors are
  expected to cause stress
• Attributions of LBP cause may affect
• the workers knowledge of back safety
• perceived job control
• likelihood of reporting LBP

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How is stress related to LBP?

• Prolonged muscle tension may
• overload muscle fibers
• result in loss of blood flow to muscles
• Overload documented in neck shoulders
• Also likely in low back
• There may be other mechanisms as well

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Hypotheses

• H1 Persons knowledgeable in back safety will
  attribute internal causes of LBP (behavior)
• H2 Less LBP in those high in back safety
  knowledge.
• H3 Perceived job control will be higher in those
  who attribute internal causes of LBP

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Hypotheses

• H4 Workers with LBP will also report high
  demands, low control low social support.
• H5Workers with LBP are more likely to attribute
  the cause to an external source.

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Specific Aims

• 1. Measure the prevalence of LBP in garment
  workers.
• 2. To observe record postures movements of
  workers performing primary job tasks.
• 3. Measure worker stress using the Karasek
  Demand-Control-Support model.

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Specific Aims (cont)

• 4. Measure workers attributions of LBP
  causation.
• 5. Use attribution theory in a new model to
  explore the associations between worker stress
  LBP.

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Research Design Methods

• Study design cross-sectional
• Study population a garment factory with
  approximately 400, mostly white, unionized,
  middle-aged women, paid by piece work
• Data collection self-administered questionnaire
  direct observation

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Research Design Methods (cont)

• Developed questionnaire observation checklist
• Developed new scales to measure attributions
  knowledge of back safety

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Data analysis

• Analysis of newly developed scales
• Univariate analyses
• Bivariate analyses
• Multivariate analyses

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Results Reliability Validity

• Karaseks Demand-Control-Support Model
• Newly developed scales
• Observation results
• Comparison of attributions of managers/supervisors
  workers

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Comparison of Workers Managers

• Workers (79) managers (100) attribute LBP to
  worker actions
• 86 of workers 31 of managers also blamed work
  conditions
• When asked which was most important
• 56 of workers said work conditions compared to
  only 6 of managers

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Results LBP Prevalence

• Any report of LBP last year 63.7
• LBP not due to sports or non-occ. causes that
  limited movement or interfered with work at home
  or on the job 36.2

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Knowledge of Back Safety

• Knowledgeable workers had high internal
  attribution (OR 4.6) p lt 0.001
• Knowledgeable workers do not report less LBP

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Perceived Job Control

• Higher control in workers with internal
  attribution job social support from the
  supervisor
• Also age income effects

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Demand-Control-Support Model

• LBP was only associated with high job demand (OR
  2.5, p lt 0.01)
• LBP was also associated with higher income (OR
  2.4, p lt 0.01)

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Attributions LBP

• More LBP in workers attributing LBP to job tasks
  (OR 4.4, p lt 0.001)
• Less LBP in workers with high supervisor social
  support (OR 0.25, p lt 0.01)
• Also age income effects

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Limitations

• Cross-sectional design
• temporality, survivor bias
• Recall bias
• Inter-rater agreement
• Unique study population
• Unmeasured variables

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Discussion - Implications 1

• Measure attributions before teaching back safety
• Improve worker control
• attributional retraining
• increasing social support

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Discussion - Implications 2

• Demand-Control-Support model may need
  modification for use with LBP
• Attribution model works well for study of LBP

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Discussion - Future Research

• Examine manager/supervisors worker attributions
  for presence of mismatch
• Use model in other occ. groups other outcomes
• Measure attributions at baseline do a
  longitudinal study

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Implications of attribution on stress,
biomechanics, LBP

• If root cause of LBP is worker actions, need
  improvements in risk communication
• If LBP is caused or contributed by work
  conditions, need env. modification

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EpilogueExpectancies Cause Responsibility

• Worker is careless-gt make worker careful
• Job is dangerous -gt make worker careful
• Job is dangerous -gt make the job safer
• Worker is careless -gt make the job safer

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Causes of LBP

• 90 due to mechanical causes
• overuse (spasm)
• trauma
• deformity (herniated disc)
• 10 due to systematic causes
• cancer
• infection
• other disease (ankylosing spondylitis)

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Types of LBP

• Acute (3-4 mos. duration)
• 80-90 spontaneously recover
• Chronic (gt4 mos. duration)
• osteoarthritis, loss of disc flexibility
• other age effects osteoporosis spinal stenosis

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Power 2 controls per case, ? .05, 1-? .80
(z?/2 z?)2 x (K1)/K x pq
n
?2

• Prevalence .36
• p1 0.70
• p2 0.53
• ? .17
• cases 100
• controls 178
• total 278

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Significant Relationships