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