attributions, stress, and work-related low back pain george byrns, mph, ph.d., cih illinois state...
TRANSCRIPT
Attributions, Stress, and
Work-Related Low Back Pain
George Byrns, MPH, Ph.D., CIHIllinois State University
Background & Significance
LBP WC claims in the US (1992)– 16% of claims – 33% of costs (>$49 billion)
Risk factors – individual, job-related, physical, & psychosocial
In spite of mechanization, LBP is still a major source of disability
Exposure
Dose Response
Capacity
Physical Stain Model
Conceptual Model for Attributions as a Risk Factor for LBP
Attributions
Resources
Psychological demand
Psychological Stress
Knowledge ofBack Safety
Low Back PainFunction
Injury
Work
EnvIronment
Physical demand
The Dimensions of Resources
Resources
Individual characteristics
Social environment
Safety climate
Age GenderFitness Body mass index Education Coping skillsSmoking Prior LBP
Job social supportHome social support
Management supportImplementation
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
How are attributions & stress related?
External, permanent, uncontrollable factors are expected to cause stress
Attributions of LBP cause may affect:– the worker’s knowledge of back safety– perceived job control– likelihood of reporting LBP
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
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
Hypotheses
H4: Workers with LBP will also report high demands, low control & low social support.
H5:Workers with LBP are more likely to attribute the cause to an external source.
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.
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.
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
Research Design & Methods (cont)
Developed questionnaire & observation checklist
Developed new scales to measure attributions & knowledge of back safety
Data analysis
Analysis of newly developed scales Univariate analyses Bivariate analyses Multivariate analyses
Results: Reliability & Validity
Karasek’s Demand-Control-Support Model Newly developed scales Observation results Comparison of attributions of
managers/supervisors & workers
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
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%
Knowledge of Back Safety
Knowledgeable workers had high internal attribution (OR = 4.6) p < 0.001
Knowledgeable workers do not report less LBP
Perceived Job Control
Higher control in workers with internal attribution & job social support from the supervisor
Also age & income effects
Demand-Control-Support Model
LBP was only associated with high job demand (OR = 2.5, p < 0.01)
LBP was also associated with higher income (OR = 2.4, p < 0.01)
Attributions & LBP
More LBP in workers attributing LBP to job tasks (OR = 4.4, p < 0.001)
Less LBP in workers with high supervisor social support (OR = 0.25, p < 0.01)
Also age & income effects
Limitations
Cross-sectional design– temporality, survivor bias
Recall bias Inter-rater agreement Unique study population Unmeasured variables
Discussion - Implications 1
Measure attributions before teaching back safety
Improve worker control – attributional retraining– increasing social support
Discussion - Implications 2
Demand-Control-Support model may need modification for use with LBP
Attribution model works well for study of LBP
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
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
Epilogue:Expectancies: Cause & Responsibility
Worker is careless-> make worker careful Job is dangerous -> make worker careful Job is dangerous -> make the job safer Worker is careless -> make the job safer