what kind of evidence is there for the prevention of musculoskeletal disorders: what workplace...

What kind of evidence is there for the prevention of musculoskeletal

disorders:What workplace interventions

really work?

Richard Wells

CRE-MSD: Centre of Research Expertise for the Prevention of Musculoskeletal Disorders

February 5th 2008

About You

Do you believe that all workplaces and all kinds of work can be improved to reduce the risk of MSDs?

What interventions have you tried and believe to work?

What kinds of evidence did you use to come to your conclusions?

What do you think are the facilitators and barriers to reducing the risk of developing MSD?

2

Messages…

Well-executed multi-component MSD prevention activities incorporating participation are best supported.

Intensity.. What, How much, How many… must be considered

Consider primary and secondary prevention There are different views of what, “really works”

means: Whose point of view?

What is measured? 3

Messages...

Ergonomic interventions take place in a complex open system… the workplace. Workplaces change frequently and when faced with a problem many organizations “throw the book at it.” Which, if any, of the changes had an effect? BUT This is currently the best approach

Where multiple good studies are available, systematic reviews are valuable tools for decision making but limited when there are few good research studies available.

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Outline

Stories Evidence Practice Relevance Using Evidence “Moving the Needle” Messages

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Story #1

XXX, a metal furniture manufacturing company, established an ergonomics program that cut lost workdays from work-related musculoskeletal disorders from 176 in 1991 to 0 in 1997. Ergonomic changes increased productivity 25%.

Source: CTD News

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Story #2

A small company had two lost time low back compensation ”cases” in a department with heavy lifting within one year.

Powered lifting assists were introduced as an engineering intervention.

One year later no reduction in the costs associated with back claims was found.

Conclusion: The intervention was a failure… (as is ergonomics?!)

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Story #2




Conclusion: The intervention was a failure…

A review of the specifications of the lift assists and in efficacy tests (in the laboratory), the assists reduced low back loads for the weights of interest.

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Story #2

A small company had two low back compensation ”cases” in a department with heavy lifting within one year.




Feedback from supervisors and workers determined that: •workers were not familiar with the use of the lift assists and didn’t use them. •breakdowns meant that they were not available much of the time.

These process measures indicated that the intensity of the intervention was low due to low coverage and adherence.

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Story #2





•Upon review of the cost data it was determined that most of the costs were due to an injury which occurred in the previous year. •Cost data were also deemed to be unstable due to the small size of the company and the limited follow up time

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Story #2

A small company had two low back compensation ”cases” in a department with heavy lifting within one year.




Lessons?

•The original conclusion was not correct

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Lessons?

Ergonomic interventions take place in a complex open system… the workplace Evaluation of “what works” is not straightforward

Ongoing change and co-interventions: workplaces change frequently: when faced with a problem an organization may “throw the book

at it.” Which, if any, of the changes had an effect?

Process measures are important, especially for transferability There may be different views of what “really works” means:

Whose point of view? What is measured?

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Evidence for what “Really Works”

What is good evidence? Whose evidence is to be believed? Is it “practical”?! Is it relevant to my organization?

13

Organizations/ Workplaces

Often find the answers they get from researchers not very satisfactory

The answers are often very general, do not seem adapted for their workplace or “need more research”.

Want research to have been translated for their specific needs or problems.

Have access to (too?) much information but have little idea of its quality and lack resources, time, or ability to synthesize knowledge.

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Strength of Evidence?

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1. Is the source a synthesis or review of many good studies

2. Do different studies and types of study agree?3. Are interventions well described or “Black Box”? 4. Is the source the “grey literature” 5. Is the source a commercially-sponsored web

sites or product literature6. Is the source anecdotes?

Systematic Reviews

Provide information about the effectiveness of

interventions by: identifying, appraising, and summarizing the results of a body of primary research

Minimize bias by using replicable and explicit

approaches

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Level of Evidence

Minimum Quality

Minimum Quantity

Consistency

Strong Very high 3 studies All very high quality studies converge on the same findings.

Moderate High 3 studies Majority of high and better quality studies converge on the same findings.

Partial Medium 2 studies Majority of medium and better quality studies converge on the same findings.

Mixed Medium 2 studies If there are two studies, they do not agree. If more than two, relatively equal numbers of studies support and do not support effectiveness.

Insufficient The above criteria are not met.

Practice Relevance?

1. Is the evidence based on research conducted in a laboratory or in a workplace?

2. Have solutions been tried in the workplace?3. Have solutions been implemented using typically

available resources?

Many a slip twixt cup and lip…

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Positive findings are evidence that a prevention approach can be effective

Negative or positive findings may be due to particular context

Understanding of the mechanisms may or may not translate to a prevention approach that “works”

Understanding injury mechanisms best guide to effective and generalizable prevention strategy

cell animal human human group society tissue tissue

workplace

In a complex open social, medico-legal system

Understanding mechanisms in simpler more controllable setting


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LaboratoryBased

Practice Ready

Partial

Moderate

Excellent

Poor

Case studies?

Epidemiologic causation studies

ProfessionalOpinion?

Interventionstudies

Physiological, anatomical, clinical biomechanical studies

Str

eng

th o

f E

vid

ence

Practice Relevance

Ideal

Using Systematic Reviews

Office Workstation Adjustment

Participative Ergonomics Programs

Back Belts

“Back Belts”

Ammendolia et al., 2005

“Currently, because of conflicting evidence and the absence of high-quality trials, there is no conclusive evidence to support back belt use to prevent or reduce lost time from occupational LBP.” (Systematic review).

McGill 1999

“Given the available literature, it would appear the universal prescription of belts (i.e., a mandatory belt wearing policy for all workers in a given industrial operation) is not in the best interest of globally reducing both the risk of injury and compensation costs”. (Mainly laboratory and field studies)

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Vote: Back Belt Use?

Based upon the best available evidence NOW and the relevance of the evidence to prevention activities:

1.Strongly recommended2.Recommended3.Recommended based on expert opinion4.No recommendation 5.Not recommended based on expert opinion6.Not recommended 7.Strongly not recommended

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Back Belts

Strength of Evidence Practice Relevance Research Recommends..

Workplace and

laboratory studies have come to similar conclusions.

Multiple studies show little evidence that they reduce spine loading or prevent back pain.

It is Not Recommended to use back belts as a general prevention strategy.

LaboratoryBased

Practice Ready

Partial

Good

Excellent

Poor

Str

ength

of

Evid

en

ce

Practice Relevance

•Ammendolia et al 2005, McGill 1999

Participative Ergonomics Approach

Cole et al., 2006 “…there is enough evidence to

recommend the use of PE interventions as a way to improve health outcomes.”

25http://www.iwh.on.ca/sr/pdf/part_ergo_sum.pdf

Vote: Participative Ergonomics Approach?


1.Strongly recommended2.Recommended3.Recommended based on expert opinion4.No recommendation 5.Not recommended based on expert opinion6.Not recommended, 7.Strongly not recommended

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Participative Ergonomics Programs

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LaboratoryBased

Practice Ready

Partial

Moderate

Excellent

Poor

Str

en

gth

of

Evid

en

ce

Practice Relevance

A systematic review concludes that there is enough evidence to support the use of participative ergonomics approaches

Studies used many kinds of

workplaces using many different kinds of participative approaches. Many practitioners believe it

to be good practice

It is Recommended to use participative ergonomics as an effective process that can improve health outcomes

Adjusting Office Furniture

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Intervention category (# of studies) no +ve Quality

Workstation adjustments (4) 4 0 2 high, 2 medium

Rest breaks + exercise (2) 2 0 1 high, 1 medium

Alternative pointing devices (2) 0 2 1 high, 1 medium

Ergonomic training (4) 2 2 1 high, 3 medium

Rest breaks (4) 2 2 1 high, 3 medium

Forearm supports (2) 1 1 1 high, 1 medium

Alternative keyboards (2) 2 2 2 high

Exercise (1) 1 0 1 medium

New Chair (1) 0 1 1 high

Systematic Review Findings

……….Workplace Interventions to Prevent Musculoskeletal and Visual Symptoms and Disorders Among Computer Users, Dwayne Van Eerd, et al., 2006 (IWH}


van Eerd et al., 2006:Moderate level of

evidence that workstation adjustments have no effect on MSK health

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Vote: Adjusting Office Furniture?


1.Strongly recommended2.Recommended3.Recommended based on expert opinion4.No recommendation 5.Not recommended based on expert opinion6.Not recommended7.Strongly not recommended

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Office Workstation Adjustments

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LaboratoryBased

Practice Ready

Partial

Moderate

Excellent

Poor

Str

en

gth

of

Evid

en

ce

Practice Relevance

Workstation adjustment is

Not Recommended as a sole action for the prevention of MSDs.

Although adjusting office equipment is necessary, it is NOT sufficient.

Systematic review concludes that office workstation adjustment has NO effect on MSDs BUT multiple good field studies show

that non-neutral posture is a risk factor . Multiple laboratory studies suggest that poor

workstations create poor posture and the

postures could lead to MSDs .

The systematic review intervention studies were

performed in offices . Studies done in offices and the lab, support adjustment. Ergonomists recommend workstation

adjustment .

http://iwh.on.ca/sr/pdf/wrkplceinter_sum.pdf


van Eerd et al., 2006:Moderate level of evidence that:

Workstation adjustments have no effect on MSK health

Workstation adjustment is

Not Recommended as a sole action for the prevention of MSDs.

Although adjusting office equipment is necessary, it is NOT sufficient.

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Possible reason for many null findings

Are the changes made as a result of the ergonomics process enough to “move the needle”? Many of the interventions to prevent MSD that

we followed had little effect because of a low intensity

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Pre

vale

nce

of

MS

D

work related: psychosocial

work related: mechanical

force

posture

repetition

control

support

demand

d

start of intervention

c

Comprehensively targets risk factors; efficacy

Successful program implementation

High intervention intensity

good sustainability

Effective Intervention

TimeAdapted from Westgaard and Winkel (1997)

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Primary Prevention: Non-work related MSD not addressed

Comprehensive, multi-component ergonomics program/process

Secondary Prevention: Workplace modification can addresses this too: “Work should be comfortable when we are well, and accommodating when we are ill”

Pre

vale

nce

of

MS

D

work related: psychosocial

work related: mechanical

force

posture

repetition

control

support

demand

start of intervention

good sustainability

Effective Intervention

TimeAdapted from Westgaard and Winkel (1997)

36

Comprehensive, multi-component ergonomics program/process

Messages…

Well-executed multi-component MSD prevention activities incorporating participation are best supported.

Intensity.. What, How much, How many… must be considered

Consider primary and secondary prevention There are different views of what, “really works”

means: Whose point of view?

What is measured? 37

Messages...

Ergonomic interventions take place in a complex open system… the workplace. Workplaces change frequently and when faced with a problem many organizations “throw the book at it.” Which, if any, of the changes had an effect? BUT This is currently the best approach

Where multiple good studies are available, systematic reviews are valuable tools for decision making but limited when there are few good research studies available.

38

Example Systematic Reviews

Cited Today

Effectiveness of Participatory Ergonomics InterventionsDonald Cole, Irina Rivilis, Dwayne Van Eerd, Kim Cullen, Emma Irvin, Jonathan Tyson,

Dee Kramer (IWH)Workplace Interventions to Prevent Musculoskeletal and Visual Symptoms and

Disorders Among Computer UsersDwayne Van Eerd, Shelley Brewer, Benjamin C. Amick III, Emma Irvin, Kent Daum, Fred

Gerr, Steve Moore, Kim Cullen, Dave Rempel (IWH}

Other ExamplesInterventions in health care settings to improve musculoskeletal health

Jessica Tullar, Benjamin C. Amick III, Shelley Brewer, Dwayne Van Eerd, Emma Irvin, Quenby Mahood, Lisa Pompeii, Anna Wang, David Gimeno, Brad Evanoff, Kiera Keown (IWH)

Manual material handling advice and assistive devices for preventing and treating back pain in workers (Review)

Martimo KP, Verbeek J, Karppinen J, Furlan A D, Kuijer PPFM, Viikari-Juntura E, Takala EP, Jauhiainen

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