Can we be scientific in the practice of occupational health - PowerPoint Presentation

Slide1

Can we be scientific in the practice of occupational health psychology? * An homage to Don Campbell

* Unceremoniously stolen from: Campbell, D.T. (1984). Can we be scientific in applied social science? In: Conner, R.F., Altman, D.G., and Jackson, C. (Eds.). Evaluation studies: Review Annual. v.9, 1984. Beverley Hills, Sage Publications, pp. 26-48.

Ted Scharf, Ph.D., Research Psychologist

National Institute for Occupational Safety and Health

Cincinnati, OhioSlide2

disclaimer –

The findings and conclusions in this presentation havenot been formally disseminated by the National Institutefor Occupational Safety and Health

and should not beconstrued to represent any agency determination orpolicy. Any findings and conclusions in this

presentation are those of the author. Slide3

please ask questions as we move along . . . Slide4

Quasi-experimental methodology:Campbell, D.T., & Stanley, J. (1966). Experimental and quasi-experimental designs for research. Boston: Houghton Mifflin Co.

Cook, T.D., and Campbell, D.T. (1979). Quasi-experimentation: Design and analysis issues for field settings. Chicago: Rand McNally.Shadish, W.R., Cook, T.D., and Campbell, D.T. (2002). Experimental and quasi-experimental designs for generalized causal inference. Boston: Houghton Mifflin Co.

Categories of validity: • statistical conclusion validity

• internal validity •

construct validity

•

external

validitySlide5

Campbell, D.T. (1984). Can we be scientific in applied social science? In: Conner, R.F., Altman, D.G., and Jackson, C. (Eds.). Evaluation studies: Review Annual. v.9, 1984.

Beverley Hills, Sage Publications, pp. 26-48.contagious cross-validationcompetitive replicationi.e. replication is the scientific response to methodological shortcomings or other problems with validity.Slide6

Example: Experimentally trained researchers tend to focus on the requirements of internal validity (e.g. requiring a “true” experiment) to the exclusion of concerns related to external validity.

Inappropriate use of a Randomized Controlled Trial (RCT):CDC study regarding the prevention of transmission of HIV from birth mother to baby, in Côte d’Ivoire and Thailand, using:reduced dosage of AZT, compared to a . . .placebo control group, rather than to the U.S. standard of careNew England Journal of Medicine

, v.337, no.12, September 18, 1997 e.g.:Angell, M. The ethics of clinical research in the third world. pp. 847-849.Lurie, P., and Wolfe,

S.M. Unethical trials of interventions to reduce perinatal transmission of the human immunodeficiency virus in developing countries. pp.853-856.Slide7

O1 O2 X O

3 O4 - - - - - - - - - - - - - - - - - - - - O1 O2 Y O3 O4CDC design: X = experimental, reduced AZT protocol

Y = placeboparticipants: HIV positive, pregnant women

In Cook and Campbell notation, the CDC research design: Slide8

A “comparison” group instead of a “control” group: O1 O2

X O3 O4 - - - - - - - - - - - - - - - - - - - - O1 O2 Y O3 O4 - - - - - - - - - - - - - - - - - - - - O

1 O2 Z O

3 O4Comparison groups design:

X = experimental, reduced AZT protocol

Y = U.S. standard AZT treatment

Z = AZT protocol, midway between X & YSlide9

The “Gold Standard” - Randomized Controlled Trial (RCT

):• random selection of subjects / participants• random assignment to experimental conditions• a “no treatment” or “

placebo” control group

• The origins of the RCT are in experimental and clinical medicine where physicians evaluate the efficacy of a particular drug or treatment

•

Often described interchangeably as “evidence-based”

Remember:Slide10

Quasi – experimental methods:• typically used with pre-existing, intact groups

measure and evaluate contributing or confounding factors• between groups and within subjects analyses• compare between different treatments• origins of program evaluation methodology are in primary and secondary educationSlide11

Reminder:When a new treatment is under test, AND . . .There is no conclusive evidence that the new treatment is more effective than the current standard, THEN . . .

We test the new treatment on a sample of eligible subjects, ANDDeliver the standard (comparison) treatment to another, different sampleANDIf there is no known effective treatment, a placebo control group may be considered as a comparison groupSlide12

Victora, C.G., Habicht, J-P., and Bryce, J. (2004). Evidence-based public health: Moving beyond randomized trials. American Journal of Public Health, v.94, no.3, pp. 400-405.

clinical efficacy trialspublic health regimen efficacypublic health delivery efficacypublic health program efficacypublic health program effectivenessSlide13

Victora (2004)

plausibility evaluation to document impact and rule out alternative explanations, e.g. with a comparison groupcomplex intervention, RCT is artificiallarge-scale demonstration requiredethical concerns preclude use of

RCT

adequacy evaluation to document time trends

assessment of intermediate steps

evaluates each step in the presumed causal pathwaySlide14

Mohr, L.B. (1995). Impact analysis for program evaluation. 2ed. Thousand Oaks, CA., Sage.

“outcome line” – (especially ch.2, Fig 2.1, p.16)preliminary, intermediate and long-term outcomes are modeledother measured factors may influence the outcomesfigure below, adapted from Mohr (1995, p.16):

Measured

Activity #1

Measured

Activity #2

Measured

Activity #3

Measured

Activity #4

Measured

Subobjective

#1

Measured

Subobjective

#2

Measured

Ultimate

Outcome

Measured

Outcome of

InterestSlide15

Mohr, (1995), when:series of related outcomes,interim objectives, or sub-objectives,

formative evaluation required,then:attempt to measure all relevant influences in a studySlide16

Disagreements between experimentally trained researchers and researchers trained in quasi-experimental social science methodology are just one example of the ways in which our work can be considered “unscientific.” Within NIOSH:Rosenstock, L. and Thacker, S. B. (May, 2000). Toward a safe workplace: The role of systematic reviews. American Journal of Preventive Medicine. Supplement. v.18, no.4S. Rivara

, F.P., and Thompson, D.C. (Eds). , pp.4-5. and the reply:NORA Intervention Effectiveness Research Team, (May, 2001). May 2000 Supplement on preventing occupational injuries. Letter to the Editor. American Journal of Preventive Medicine. v.20, no.4. pp. 308-309.Theoretical perspective (a.k.a. “world views”) can exert a great influence on the conduct of the research.Slide17

Altman, I., Rogoff, B., (1987). World views in psychology: Trait, interactional, organismic, and transactional perspectives. In: D. Stokols and I. Altman, (Eds.). Handbook of environmental psychology. v.1.

New York: John Wiley and Sons.World View PerspectiveUnit of Analysis over Time

Observers & Focus

Trait

person & individual psychological processes; emphasis on stable features; change is reflected in predictable, ordered, usually developmental stages.

separate, objective, & detached observers; emphasis on traits and universal laws.

Interactional

person, social, & physical environment are independent entities; interaction of the separate entities, resulting in changes of state in the separate entities.

separate, objective, & detached observers; focus on relations between separate elements.

Organismic

h

olistic

entities or integrated systems composed of distinct person & environment components in interaction; interactions are predictable and trend toward homeostasis.

separate, objective, & detached observers; holistic systems in a hierarchy with subsystems.

Transactional

h

olistic

entities composed of aspects of the whole, where the aspects are mutually defining; change is continuous, intrinsic, and not pre-determined.

observers are aspects of the phenomena, yielding different observations from different observers; focus on identifying the patterns of the event

under

examination.Slide18

Example: The “classic” hierarchy of control.

I. Engineering Controls A. eliminate the hazard

B. substitution of material, equipment, or process

C. isolation of hazard, e.g., barriers and/or removing the worker(s)

D. ventilation of airborne contaminants

II

. Administrative Controls to reduce exposure

A. reduced work hours

B. employee education and training

1. improved hazard recognition

2. improved work practices

III. Personal Protective Equipment (PPE

)

(Adapted from

Raterman

, 1996, and Office of Technology Assessment, 1985

.)Slide19

what else do we know about hazardous work environments ??Slide20

Common features in hazardous work environments – constant change:Variability in: time space

/ location motionCharacteristics or properties of workplace hazards: force(s) creating or causing the hazard types of efforts to control the hazard

traditional hierarchy of control degree worker control

likelihood of failure of controls

predictability and salience

work process hazard

severity of risk, following exposure

interactions with other hazardsSlide21

Worker-centered approach to hazardous work environments:Contrary to the traditional Hierarchy of Control:

1) except where a hazard has been completely eliminated from the environment, worker control and participation in managing the hazard are essential; and 2) when the work process is extremely time-limited ‑ or is an actual emergency ‑ workers are most likely to neglect their own safety to complete the emergent task.Slide22

dual-attention demand:safety vs. productivity

thus, especially in hazardous work environments, there appears to be an incompatible and conflicting set of demands that impinge on front-line workers (in particular):Slide23

dual-attention demand:safety AND

productivityHOWEVER, from the point-of-view of OHP, our perspective on this problem must be:How can we approach this problem?How can we train workers to adopt this perspective and attitude?Slide24

brief digression:Aren’t we compromising safety when we permit considerations of productivity to enter into discussions of safety?Slide25

brief digression:Aren’t we compromising safety when we permit considerations of productivity to enter into discussions of safety?

Traditional workplace safety and health viewpoint: - economics and productivity never mentioned with respect to safety - to include economics is to balance a worker’s life in the same equation with the costs of production - fundamental principle: safety may not be compromised for any reasonSlide26

brief digression:Aren’t we compromising safety when we permit considerations of productivity to enter into discussions of safety?

The real world: - safety is compromised every day on the job, especially in hazardous work environments - employees will take risks with their own lives to maintain production, (including in situations where they will not directly benefit) - especially when fatigued, attention to the production task becomes rote, and attention to changing hazards in the surrounding environment ceasesSlide27

brief digression:Aren’t we compromising safety when we permit considerations of productivity to enter into discussions of safety?

NIOSH and others have come to realize that if we are truly interested in worker safety, we must develop realistic safety training that incorporates day-to-day productivity pressures into the training. By addressing safety in its real-world context, we: - enhance safety as a practical, usable, workplace skill - strive to incorporate safety into the production process, such that, “the safest way is also the easiest and most productive way.” (Susan Baker, Johns Hopkins)Slide28

“what gets measured, gets managed”

Professor Peter ChenColorado State UniversityUniversity of South AustraliaOrlando, FL., May 18, 2011Slide29

Stokols, D. (1987). Conceptual strategies of environmental psychology. In: D. Stokols and I. Altman, (Eds.). Handbook of environmental psychology. v.1. New York: John Wiley and Sons

.andStokols, D. (1992). Establishing and maintaining healthy environments: Toward a social ecology of health promotion. American Psychologist. v.47, no.1, pp.6-22.andStokols, D. (2006). Toward a science of

transdisciplinary action research. American Journal of Community Psychology, v.38, pp.63-77.Slide30

Establishing a contextual perspective; the core assumptions (Stokols, 1987, pp.42-43):1. psychological phenomena should be viewed in the spatial, temporal, and sociocultural milieu in which they occur;2. a focus on individuals’ responses to discrete stimuli and events in the short run should be supplemented by more molar and longitudinal analyses of people’s everyday activities and settings;3. the search for lawful and generalizable relationships between environment and behavior should be balanced by a sensitivity to, and an analysis of, the

situation specificity of psychological phenomena;4. the criteria of ecological and external validity should be explicitly considered (along with the internal validity of the research) not only when: - designing behavioral studies,but also when: - judging the applicability of research findings to the development of public policies and community interventions.Slide31

This is the search for and identification of the target phenomenon and the relevant contextual variables.The contextual variables may be identified through: - an exploratory and atheoretical process, or - a fully developed contextual theory Slide32

Example: Florida Department of Health responses to the 2004 hurricane seasonSlide33
Slide34
Slide35
Slide36

Structural equation (two) models:

1. Both work organization and hurricane exposure measures. Purpose: to establish that the work organization measures contribute to a model in which the hurricane exposure measures are included as predictors.2. Work organization measures alone. Purpose: to

identify an upper-bound estimate for the effects of the work organization measures (i.e. without competing with hurricane exposure measures). Slide37

ill

health6/2005badmentalhealthdays6/2005presenteeism

6/2005return

to normal2004-2005

job

dissatisfaction

2004-2005

difficulty

balancing

work & family

2004

distress

during

hurricanes

2004

emotional

experiences of

hurricanes

2004

USUHS

hurricane

exposure

scale - 2004

amount

of sleep

2004

hours

worked

2004

number of

hurricanes

worked

2004

prior

hurricane experience

before

2004

prior

hurricane

training

before

2004

W

O

R

K

O

R

G

A

N

I

Z

A

T

I

O

N

T

O

P

I

C

S

2004Slide38

hypothesized direction (sign of the coefficient)

opposite the hypothesized direction (opposite sign of the coefficient)

measured

variablelatent

variable

(construct)

p<0.05

p<0.01

p<0.001Slide39

Structural equation (two) models:

1. Both work organization and hurricane exposure measures. Purpose: to establish that the work organization measures contribute to a model in which the hurricane exposure measures are included as predictors.2. Work organization measures alone. Purpose: to

identify an upper-bound estimate for the effects of the work organization measures (i.e. without competing with hurricane exposure measures). Slide40

ill - health

6/2005badmentalhealthdays6/2005presenteeism6/2005

return

to normal2004-2005

job

dissatisfaction

2004-2005

difficulty

balancing

work & family

2004

distress

during

hurricanes

2004

communication

& work

organization

prob. 2004

safety

conflict

2004

role conflict/

compatibility

2004

social

support

2004

control

2004

workload

2004Slide41

The social ecology of health promotion core assumptions (Stokols, 1992, pp.7-8):1. efforts to promote human well-being should be based on an understanding of the dynamic interplay among diverse environmental and personal factors;2. analyses of health and health promotion should address the multidimensional and complex nature of human environments, including: - physical and social components - objective and subjective qualities - scale or immediacy (proximal vs. distal) to individuals and groups

- independent environmental attributes or composite relationships among several environmental features; Slide42

The social ecology of health promotion core assumptions (Stokols, 1992, pp.7-8), continued:3. environmental scale and complexity: - individuals - small groups - organizations - populations i.e. multiple levels of analysis using diverse methodologies;4. dynamic interrelations (or transactions) between people and

environments: - physical and social features of settings influence participants’ health - participants modify their surroundings - interdependencies between immediate & distant environments, e.g. local, state, and national-level regulations for safety & healthSlide43

Scope of transdisciplinary research, (Stokols

, 2006, p.66):Slide44

What are the disciplinary boundaries of OHP ?Put another way, what are the most important disciplines with which OHP must interact ?Slide45

Some candidate disciplines that are essential to OHP: health, industrial/organizational, community, and environmental psychology,plus

epidemiology, public health, occupational medicine, industrial hygiene, safety engineering, and anthropology, sociology, economics. Slide46

Stokols, D. (2006). Toward a science of transdisciplinary action research. American Journal of Community Psychology, v.38, pp.63-77.

andRosenfield, P.L., (1992). The potential of transdisciplinary research for sustaining and extending linkages between the health and social sciences. Social Science and Medicine. v.35, no.11, pp.1343-1357.Continuum of collaboration

Characteristics of the degree of collaboration and subsequent approach to investigation and research

disciplinary

the study of a scientific phenomenon from one perspective, typically reflecting 1) distinctive substantive concerns, 2) analytic levels, and 3) concepts, measures and methods; boundaries between disciplines may be overlapping, and may spawn a new focused discipline

multidisciplinary

different disciplines working independently or sequentially on a common problem

interdisciplinary

different disciplines sharing information, but the component disciplinary models and methods remain unchanged

transdisciplinary

researchers from different disciplines create a shared conceptual framework that integrates and extends discipline-based concepts, theories, and methods to address a common research topic.Slide47

something to ask your students: “which comes first . . . the question or the answer ?”Slide48

and: “where do research hypotheses come from ?”Slide49

brief review:quantitative methods – - test existing hypotheses (e.g., consider or rule-out) - assess concepts we have measured (quantitatively) - reduce observed results to manageable findings - enable systematic, replicable, and verifiable

measurement, i.e. fundamental sciencequantitative methods do not – - generate novel explanations about things or events, e.g. propose new causal pathways - suggest explanations not previously measuredSlide50

qualitative methods – - describe and/or explain phenomena or events - interpret and/or “model” processes or events - may replicate and verify . . . or suggest unknown processes

or relationships, at same time they provide empirical data to generate hypotheses or verify a quantifiably testable hypothesisqualitative methods provide data specific to a sample and target population from which it was derivedseries of qualitative interviews or focus groups produces an iterative and progressive investigation of the selected topicSlide51

qualitative methods usually are not designed to – - generalize beyond the actual sample, unless data collected for this purpose, and replicated with subsequent,

independent groups - test hypotheses empirically, unless the sample size is appropriate, i.e., group characteristics sufficiently known to determine heterogeneous or homogeneous, and every participant responds to each question or hypothesis Slide52

Example using qualitative methods: topic of investigation: risks for injury among family farmers, e.g. Kidd, et al., 1996 method of investigation:

series of focus groups farm family members are judges regarding the farm environment – look for agreement between the participants both within groups and across the series of groups sample the maximum variability in farm environments different regions different enterprises (crops, livestock, etc.) different sizes of operations

each group should be relatively cohesive / homogenousSlide53

Example of a qualitative method generating a model to be tested quantitatively:Kidd, et al., 1996Slide54

Building a Research TeamOrganizational representation (local) clinic professionals & staff

business owners/managers labor union(s) representatives social service agenciesCommunity representationProfessional / technical expertise academia/research manufacturer(s) non-governmental organizations (NGO’s) public health & other government orgs.Slide55

Also:Research subjects / patientsPatient advocatesFamily members of clients, patients, or workersOther workers & community membersTypically NOT part of research team – why? – why not?Slide56

Traditional experimental science measures subjects’ behavior, attitudes, etc., but does not involve the “objects” of the research in the planning.However, qualitative methods show us the way to systematically elicit research hypotheses from our subjects.Therefore, asking members of the subject class or group to help plan the implementation of the research is just an extension of our focus group example. Result: ordinary research / evaluation study with the insight and participation of representatives of your subjects as research team members.Slide57

Example:Simple Solutions – nursery tool development processmulti-disciplinary team from University of California, Davisthree large nursery companiesOSHA 200 logsergonomic checklist completed by workers and supervisorsinterviews with workers and supervisors

Janowitz, et al., 1998; and Prof. John Miles, personal communication, 2004.Slide58

Simple Solutions – nursery tool development processhigh risk job tasks selected (high risk for work-related musculo-skeletal disorders)tool design involved nursery workers and university teamworkers and team – together – designed the toolsimperfect or incorrect designs were manufactured because workers made the suggestionthen the workers helped design improvementsJanowitz, et al., 1998; and Prof. John Miles, personal communication, 2004.Slide59

Summary: Participatory Action Research (PAR) in hazardous work environments.

ProjectPartners

Partners’ role

Researchers’ role

p – 2 – r

results

Kentucky Farm Family Health and Hazard Surveillance Program

Kentucky farmers

Describing, explaining, and interpreting the key issues and how these topics are linked.

Creating a model based on the farmers’ interpretations

Model: “Linking stress and injury in the farming environment:...”

Cross-cutting Research and Interventions in Hazardous Work

Environments

KY

livestock farmers/ ranchers

Iteratively developing and testing checklist items; prioritizing checklist items; suggesting modifications and additional items in subsequent iterations

Recording and organizing the results; seeking input from independent subject matter experts; editing the final lists; developing formal evaluation studies with new groups of workers.

Checklist: Safe Cattle Handling Critical Action Factors.

Small construction company owners in

KY

Checklists: Guidelines for Extension Ladder

Safety

Hazard recognition: preventing falls and close calls

Journeymen ironworkers; primarily apprentice trainers

Participate in exploratory and confirmatory focus groups; confirmatory groups proposed the project: “Unreported Incidents...” (below).

Developing and revising focus group interview guide; probing new areas of inquiry identified by focus group participants; identifying new questions based on the focus group statements.

Summary

of the focus group findings

Proposed project:

Unreported Incidents, Injuries, & Illnesses with Ironworkers.

Core team composed of journeymen ironworkers who train apprentices in union locals.

Create, direct, and implement an investigation of the actual number of incidents, injuries, and illnesses among Ironworkers, starting with

apprentices.

Technical support to the project: assembling Core Team decisions into the components of a research project; HSRB protocol and review; developing analytic templates for reporting the findings.

Goal: on-going electronic surveillance tool for use by the Ironworkers and other union locals

.Slide60

What does all this mean for OHP, NIOSH and all of CDC?National Institute FOR Occupational Safety and HealthNational Center FOR Injury Prevention and Control

National Center FOR Environmental HealthNational Center FOR HIV/AIDS, Viral Hepatitis, STD, and TB PreventionNational Center FOR Chronic Disease Prevention and Health PromotionAll in the:Centers FOR Disease Control and PreventionConclusion: like NIOSH, Occupational Health Psychology promotes safety and health at work.Slide61
Slide62
Slide63

Health care interventions, changes to improve workplace safety and health, and even pre-placement exams are (essentially) components of natural experimentsIdentifying and developing systematic measurements of interventions and workplace programs are tasks of

researchOnce systematic measurements are collected, the interventions and workplace programs will then include a study of intervention effectivenessResults from the evaluation of effectiveness may be used to:improve current effectivenessidentify additional program needspromote diffusion of the intervention to additional communities, occupations, other participantsPerspective on evaluation methodology:Slide64

Interventions for injury prevention and health promotion, or a few specifics that illustrate the preceding discussion:

Training style:

learner centered training active participation

problem solving

discussions among / between co-workers

crew-based solutions to problems

encourage creative approaches to problems

transfer of skills

from experienced to less

experienced job / task performers

site-specific focus,

especially with intact work crews:

discuss

prior workplace hazards,

problems,

and the solutions developed

promote

crew approaches

to specific

problems on-siteSlide65

Training principles:

front-line worker control is essential where hazards are present promote good communication, cooperation, and pre- planning between workers and front-line supervisors safety is a skill integrate safety with production as the performance standard, i.e.

safety and productivity are inter- dependent in the work organization and processes

subject-matter experts (including veteran workers) identify hazards and develop plans to reduce riskSlide66

Training principles - 2:

hazard recognition: is not simply identifying existing problems in the work environment includes anticipating incipient problems that may be likely to develop once identified, hazards can be prioritized for elimination or mitigation, with an emphasis on

reducing risk

crew-based solutions promote: improved safe-work practices

reduction in variability on critical tasks

improved safety climateSlide67

References:Altman, I., Rogoff, B., (1987). World views in psychology: Trait, interactional, organismic, and transactional perspectives. In: D. Stokols and I. Altman, (Eds.). Handbook of environmental psychology. v.1. New York: John Wiley and Sons. Angell, M. (1997). The ethics of clinical research in the third world. New England Journal of Medicine. v.337, no.12. (September 18, 1997.) pp.847-849.  Baron, S., Estill, C.F., Steege, A., and

Lalich, N., (Eds.) (2001). Simple solutions: Ergonomics for farm workers. National Institute for Occupational Safety and Health, Cincinnati, Ohio. DHHS (NIOSH) Publication No. 2001-111. Campbell, D.T. (1984). Can we be scientific in applied social science? In: Conner, R.F., Altman, D.G., and Jackson, C. (Eds.). Evaluation studies: Review Annual. v.9, 1984. Beverley Hills, Sage Publications, pp. 26-48.)  Campbell, D.T., & Stanley, J. (1966). Experimental and quasi-experimental designs for research. Boston: Houghton Mifflin Co. Cole, H.P. (1997). Stories to live by: A narrative approach to health behavior research and injury prevention. In: Gochman, D.S., ed. Handbook of health behavior research IV: Relevance for professionals and issues for the future. New York, NY: Plenum Press., pp. 325-349.Cole, H.P., Lehtola, C.J., Thomas, S.R., and Hadley, M. (2005). No way to meet a neighbor, 2ed. Simulation exercise. Available at: http://nasdonline.org/document/1014/9/d000997/the-kentucky-community-partners-for-healthy-farming-rops-project.html.Slide68

References - 2Cole, H.P., Lehtola, C.J., Thomas, S.R., and Hadley, M. (2000). Facts about tractor/motor vehicle collisions. Available at: http://nasdonline.org/static_content/documents/1014/TMVC%20doc.pdf. Cook, T.D., and Campbell, D.T. (1979). Quasi-experimentation: Design and analysis issues for field settings.

Chicago: Rand McNally. Glascock, L.A., Bean, T.L., Wood, R.K., Carpenter, T.G., and Holmes, R.G. (1995). A summary of roadway accidents involving agricultural machinery. Journal of Agricultural Safety and Health. v.1, no.2, pp.93-104. Janowitz, I., Meyers, J.M., Tejeda, D.G., Miles, J.A., Duraj, V., Faucett, J., and Kabashima, J. (1998). Reducing risk factors for the development of work-related musculoskeletal problems in nursery work. Applied Occupational & Environmental Hygiene. v.13, no.1, pp 9-14. (Now published as the Journal of Applied Occupational & Environmental Hygiene.)  Kidd, P.S., Scharf, T., and Veazie, M.A. (1996). Linking stress and injury in the farming environment: A secondary analysis of qualitative data. In: C.A. Heaney and L.M. Goldenhar, (Eds.). Health Education Quarterly. Theme: Worksite health programs. v.23, no.2, pp. 224-237.

Kowalski, K.M., Fotta, B., and Barrett, E.A. (1995, August). Modifying Behavior to Improve Miners' Hazard Recognition Skills Through Training. Proceedings of the Twenty-Sixth annual Institute on Mining Health, Safety and Research. Blacksburg, VA, pp.95-104. Slide69

References - 3Lurie, P., and Wolfe, S.M. (1997). Unethical trials of interventions to reduce perinatal transmission of the human immunodeficiency virus in developing countries. New England Journal of Medicine. v.337, no.12. (September 18, 1997). pp.853-856.Mohr, L.B. (1995). Impact analysis for program evaluation. 2ed. Thousand Oaks, CA., Sage.National

Highway Transportation Safety Administration (2011, April). Early estimate of motor vehicle traffic fatalities in 2010. Traffic Safety Facts: Crash Stats. DOT HS 811 451. Available at: http://www-nrd.nhtsa.dot.gov/Pubs/811451.pdfNational Highway Transportation Safety Administration (2011, July). Seat belt use in 2010 – Use rates in the states and territories. Traffic Safety Facts: Crash Stats. DOT HS 811 493. Available at: http://www-nrd.nhtsa.dot.gov/Pubs/811493.pdfNational Highway Transportation Safety Administration (2008). 2006 motor vehicle occupant protection facts. DOT HS 810 654. Available at: http://www.nhtsa.gov/DOT/NHTSA/Traffic%20Injury%20Control/Articles/Associated%20Files/810654.pdf.NORA Intervention Effectiveness Research Team, (May, 2001). May 2000 Supplement on preventing occupational injuries. Letter to the Editor. American Journal of Preventive Medicine. v.20, no.4. pp. 308-309.Slide70

References - 4Office of Technology Assessment, U.S. Congress. 1985. Preventing Illness and Injury in the Workplace. ch.9, pp.173-185. OTA‑H‑256 Washington, D.C.Perdue, C., Kowalski, K.M., and Barrett, E.A. (1994). Hazard Recognition in Mining: A Psychological Perspective. US Bureau of Mines, Department of the Interior, Circular IC #9422. Raterman, S.M. 1996. Methods of control. In: Plog

, B.A., Niland, J., and Quinlan, P.J., (eds). Fundamentals of Industrial Hygiene. 4th ed, ch.18, pp.531-552. National Safety Council, Itasca, IL. Revised from: Olishifski, J.B. 1988. Methods of control. In: Plog, B.A., Benjamin, G.S., and Kerwin, M.A. (eds). Fundamentals of Industrial Hygiene. 3rd ed, ch.20, pp.457-474. National Safety Council, Chicago, IL.Rethi, L., Flick, J., Kowalski, K., and Calhoun, R. (1999). Hazard recognition training program for Construction, maintenance and repair activities. Pittsburgh, PA., DHHS (NIOSH): 99-158.Robson, L.S., Shannon, H.S., Goldenhar, L.M., and Hale, A.R. (2001). Guide to evaluating the effectiveness of strategies for preventing work injuries: How to show whether a safety intervention really works. National Institute for Occupational Safety and Health, Cincinnati, Ohio. Institute for Work and Health, Toronto, Canada. DHHS (NIOSH) Publication No. 2001-119.Rosenfield, P.L., (1992). The potential of transdisciplinary research for sustaining and extending linkages between the health and social sciences. Social Science and Medicine. v.35, no.11, pp.1343-1357.Slide71

References - 5Rosenstock, L. and Thacker, S. B. (May, 2000). Toward a safe workplace: The role of systematic reviews. American Journal of Preventive Medicine. Supplement. v.18, no.4S. Rivara, F.P., and Thompson, D.C. (Eds). , pp.4-5. Scharf, T., Hunt, J., III, McCann, M., Pierson, K., Repmann, R., Migliaccio

, F., Limanowski, J., Creegan, J., Bowers, D., Happe, J., and Jones, A. (2011). Hazard Recognition for Ironworkers: Preventing Falls and Close Calls – Updated Findings. In, Hsaio, H., Keane, P. (Eds.). “Research and Practice for Fall Injury Control in the Workplace: Proceedings of International Conference on Fall Prevention and Protection.” Morgantown, WV., NIOSH. May 18-20, 2010. Scharf, T., Vaught, C., Kidd, P., Steiner, L., Kowalski, K., Wiehagen, B., Rethi, L., and Cole, H. (2001). Toward a typology of dynamic and hazardous work environments. Human and Ecological Risk Assessment. v.7,no.7, pp.1827‑1841.Shadish, W.R., Cook, T.D., and Campbell, D.T. (2002). Experimental and quasi-experimental designs for generalized causal inference. Boston: Houghton Mifflin Co. Stokols, D. (1987). Conceptual strategies of environmental psychology. In: D. Stokols and I. Altman, (Eds.). Handbook of environmental psychology. v.1. New York: John Wiley and Sons. Stokols, D. (1992). Establishing and maintaining healthy environments: Toward a social ecology of health promotion. American Psychologist. v.47, no.1, pp.6-22.Slide72

References - 6  Stokols, D. (2006). Toward a science of transdisciplinary action research. American Journal of Community Psychology, v.38, pp.63-77. Victora, C.G., Habicht, J-P., and Bryce, J. (2004). Evidence-based public health: Moving beyond randomized trials.

American Journal of Public Health, v.94, no.3, pp. 400-405.Villarejo, D., Lighthall, D., Williams, D., Souter, A., Mines, R., Bade, B., and Samuels, S., (2000). Suffering in silence: A report on the health of California’s agricultural workers. California Institute for Rural Studies, Davis, CA. Available at: http://www.cirsinc.org/news.html#SiS Wiehagen, B., Conrad, D., Friend, T., and Rethi, L. (2002). Considerations in training on-the-job trainers. pp.27-34. In: Peters, R.H., (Ed.). Strategies for improving miners’ training. Information Circular 9463. Pittsburgh, PA., DHHS (NIOSH) Publication No. 2002-156.  Wiehagen, W.J., Conrad, D.W., and Baugher, J.M. (2006). Job training analysis: A process for quickly developing a roadmap for teaching and evaluating job skills. Information Circular (IC) 9490. Pittsburgh, PA: National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, DHHS (NIOSH) Publication No. 2006-139. August, 2006. Wiehagen, W.J., Lineberry, G.T., and Rethi, L.L., (1996). The Work Crew Performance Model: A Method for Defining and Building Upon the Expertise Within an Experienced Work Force,

SME Transactions, Vol. 298, pp. 1925-1931.Slide73

Thank you . . . .