Research methods in occupational health psychology robert r sinclair, mo wang, lois e tetrick, routledge, 2013 scan

Library of Congress Cataloging in Publication Data Research methods in occupational health psychology : measurement, design, and data analysis / edited by Robert R.. He also received Ear

Research Methods in Occupational Health

Psychology

Research Methods in Occupational Health

George Mason University

First published 2013

by Routledge

711 Th ird Avenue, New York, NY 10017

Simultaneously published in the UK

by Routledge

27 Church Road, Hove, East Sussex BN3 2FA

Routledge is an imprint of the Taylor & Francis Group, an informa business

© 2013 Taylor & Francis

Th e right of the editors to be identifi ed as the authors of the editorial material, and of the authors for their individual chapters, has been asserted in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988.

All rights reserved No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereaft er invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers.

Trademark notice: Product or corporate names may be trademarks or registered

trademarks, and are used only for identifi cation and explanation without intent to infringe.

Library of Congress Cataloging in Publication Data

Research methods in occupational health psychology : measurement, design, and data analysis / edited by Robert R Sinclair, Mo Wang, Lois E Tetrick.

p cm.

Includes bibliographical references and index.

ISBN 978-0-415-87932-3 (hardback : alk paper)

1 Industrial psychiatry 2 Clinical health psychology—Research—Methodology.

I Sinclair, Robert R II Wang, Mo III Tetrick, Lois E

Typeset in Minion and Optima

by EvS Communication Networx, Inc.

Bengt B Arnetz and Matthew Ventimiglia

Robert J Gatchel, Emily Brede, Yunhee Choi, Krista Howard,

and Whitney E Worzer

M Gloria González-Morales, Lois E Tetrick, and Ryan Ginter

June J Pilcher, Michelle L Burnett, and James A McCubbin

Seth Kaplan, Reeshad S Dalal, and Joseph N Luchman

6 How to Think About and Measure Psychological Well-Being 76

Peter Warr

7 Measurement of Interpersonal Mistreatment in Organizations 91

Lilia M Cortina and Lisa A Marchiondo

8 The Measurement of Depression and Anxiety in Occupational

Jay C Thomas, Björn Bergström, and Johan Rosqvist

9 Measurement of Posttraumatic Stress Disorder in an

Amy B Adler, Terence M Keane, and Paul D Bliese

Wilmar B Schaufeli

11 Cognitive Assessment: Implications for Occupational Health

Gerald Matthews, April Rose Panganiban, and Kirby Gilliland

12 Experimental and Quasi-Experimental Designs in

Peter Y Chen, Konstantin P Cigularov, and Lauren M Menger

13 Event-Sampling Methods in Occupational Health Psychology 208

Sabine Sonnentag, Carmen Binnewies, and Sandra Ohly

14 Sampling in Occupational Health Psychology: An

Sue Ann Sarpy, Felicia Rabito, and Nancy Goldstein

15 Quantitative Self-Report Methods in Occupational Health

Erin M Eatough and Paul E Spector

16 Strengths and Limitations of Qualitative Approaches to

Irvin Sam Schonfeld and Joseph J Mazzola

17 Use of Archival Data in Occupational Health Psychology

Research 290

Gwenith G Fisher and Janet L Barnes-Farrell

18 An Overview of Multilevel Modeling in Occupational Health Psychology 323

Lisa M Kath, Scott C Roesch, and Mark G Ehrhart

vi Contents

19 Person-Centered Analysis: Methods, Applications, and

Mo Wang, Robert R Sinclair, Le Zhou, and Lindsay E Sears

E Kevin Kelloway and Lori Francis

Robert R Sinclair, Mo Wang, and Lois E Tetrick

Contents vii

About the Editors

Robert Sinclair is an Associate Professor of Industrial and

Organiza-tional Psychology at Clemson University, where he also serves as the Graduate Program Coordinator for the Department of Psychology He completed his PhD in industrial/organizational psychology at Wayne State University in 1995 Prior to moving to Clemson University in 2008,

he held faculty positions at the University of Tulsa and Portland State University Dr Sinclair is a founding member and Past-President of the Society for Occupational Health Psychology He currently serves as an

editorial board member for the Journal of Occupational Health ogy, Journal of Management, and Journal of Organizational Behavior

Psychol-and as a panel member for the Occupational Safety Psychol-and Health Study Section of the National Institute for Occupational Safety and Health His recent work includes an edited volume (in press with Jonathan

Houdmont and Stavroula Leka), Contemporary Occupational Health Psychology: Global Perspectives on Research and Practice (Vol 2) and an edited volume (in press with Tom Britt) titled Psychological Resilience in

on individual (e.g., personality) and organizational (e.g., leadership) factors that contribute to occupational health concerns faced by mili-tary personnel, nurses, and entry-level hourly employees His specifi c interests include economic stress, the employment relationship, work schedules, counterproductive workplace behavior, and psychological resilience

Mo Wang is an Associate Professor of Management at University of

Florida, where he also serves as the codirector of the Human Resource Research Center He received his joint PhD in industrial-organizational psychology and developmental psychology at Bowling Green State Uni-versity in 2005 Prior to moving to University of Florida, he held faculty positions at Portland State University (2005–2008) and the University

of Maryland (2009–2011) Dr Wang specializes in research and tions in the areas of retirement and older worker employment, occupa-tional health psychology, cross-cultural HR management, leadership, and advanced quantitative methodologies He has received Academy

applica-of Management HR Division Scholarly Achievement Award (2008), Careers Division Best Paper Award (2009), and Erasmus Mundus Schol-arship for Work, Organizational, and Personnel Psychology (2009) for his research in these areas He also received Early Career Achievement Awards from Society for Industrial-Organizational Psychology (2012), Academy of Management’s HR Division (2011) and Research Methods Division (2011), and Society for Occupational Health Psychology (co-sponsored by the APA and NIOSH, 2009) He currently serves as an

Associate Editor for Journal of Applied Psychology He also serves on the Editorial Boards of Personnel Psychology, Journal of Management, Organizational Research Methods, Journal of Occupational Health Psy- chology, and Journal of Business and Psychology

Lois Tetrick received her doctorate in industrial and organizational

psychology from Georgia Institute of Technology in 1983 Upon pletion of her doctoral studies, she joined the faculty of the Department

com-of Psychology at Wayne State University and remained there until 1995 when she moved to the Department of Psychology at the University

of Houston She joined the faculty at George Mason University as the Director of the Industrial and Organizational Psychology Program in

2003 Dr Tetrick served as Editor of the Journal of Occupational Health Psychology (2006–2010), Associate Editor of the Journal of Occupational Health Psychology (2002–2006), and Associate Editor of the Journal

of Applied Psychology (1996–2001) She currently serves on the rial boards of Journal of Organizational Behavior, Journal of Manage- rial Psychology, Journal of Applied Psychology, and Management and Organizational Review She coedited the fi rst and second editions of the Handbook of Occupational Health Psychology with James C Quick and Health and Safety in Organizations with David Hofmann She also

Contextual Perspectives with Jacqueline Coyle-Shapiro, Lynn Shore,

and Susan Taylor Dr Tetrick is a founding member of the Society for Occupational Health Psychology and a fellow of the European Acad-emy of Occupational Health Psychology, the American Psychological Association (APA), the Society for Industrial and Organizational Psy-chology (SIOP) and the Association for Psychological Science (APS)

She served as 2007–2008 President of SIOP, the Chair of the Human Resources Division of the Academy of Management (2001–2002), and has represented SIOP on the American Psychological Association (APA) Council of Representatives (2003–2005), and the APA Board of Scientifi c Aff airs (2006–2009) Dr Tetrick’s research interests are in the areas of occupational health and safety, occupational stress, and the work–family interface Her other area of research focuses on psycho-logical contracts and the exchange relationship between employees and their organizations A common underlying interest in both of these lines of research is incorporating a global perspective in understanding employees’ experiences of the work environment.

About the Contributors

Reeshad S Dalal

George Mason UniversityFairfax, VA

Joseph J Mazzola

Roosevelt UniversitySchaumburg, IL

James A McCubbin

Clemson UniversityClemson, SC

Sue Ann Sarpy

Sarpy and Associates, LLC

Charlottesville, VA

Wilmar B Schaufeli

Utrecht University

Irvin Sam Schonfeld

University of New York

Matthew Ventimiglia

Wayne State UniversityDetroit, MI andUniversity of Detroit MercyDetroit, MI

Whitney E Worzer

University of Texas-ArlingtonArlington, TX

For the past 35 years, I have had the privilege of helping to foster the growth and development of the fi eld of occupational health psychology (OHP) In looking back at my experiences, an inescapable conclusion for me is that the growth of OHP as a discipline has been commensu-

rate with (and in part a result of) our attention to methodological rigor

In contrast to the early years of Journal of Occupational Health chology (JOHP) when both submission and rejection rates were low, we

Psy-now receive over 225 manuscripts per year with a rejection rate cipally for methodological reasons) of over 93% Over the years, scru-pulous attention to study design, measurement, and analytic issues has increasingly allowed OHP researchers to both successfully compete for funding and publish study results Needless to say, attention to meth-odological rigor continues to be an important key to successful OHP research funding, publishing, and the continued growth of our fi eld Indeed, given cutbacks by funding sources over recent years, this atten-

on OHP research methodology is both signifi cant and timely

Attention to methodological rigor has also brought a modicum of much needed recognition of OHP from scholars (and funding sources)

in other disciplines Exceptionally high quality studies examining work related psychological factors as principal predictors, mediators, or out-

comes are now published not only in JOHP and other well-respected

psychology journals but increasingly in a variety of “mainstream” occupational medicine, public health, and occupational safety jour-nals While this is encouraging, it is quite clear that OHP has not yet achieved the level of recognition we are aiming for and until we gain full-fl edged recognition within the broader contextual fi elds of psy-chology and, perhaps more importantly, occupational health and safety (OH&S), we cannot realize our full potential as a unique and indepen-dent discipline To this end, it is important for us to fully recognize that

our principal focus is on occupational health and safety, and while we may approach it from a psychological perspective, we share the occupa-tional health and safety focus with researchers in the fi elds of occupa-tional epidemiology, medicine, safety, and nursing; industrial hygiene; ergonomics; health physics; and others

Each of these fi elds has rich (and long standing) research traditions and utilizes research methodologies that have applicability to OHP Indeed, through the appreciation and use of these methodologies, we can attract greater research funding, make even greater contributions

to the understanding of occupational health and safety, more easily publish in mainstream OH&S journals, and further increase our fi eld’s

method-ological issues that arise in “traditional” OHP research, also provides the reader with an exposure to the benefi ts of some of the methodolo-

enormously important

Finally, OHP is oft en described as an interdisciplinary fi eld senting a broad range of backgrounds, interests and specializations As noted above, we share with a variety of other fi elds the common inter-est of advancing understanding of OH&S While I don’t believe we are yet a fully interdisciplinary fi eld, there has been a steady increase in interest in OHP and the methodologies of OHP among scholars in the more mainstream OH&S fi elds and others (e.g., sociology, industrial

such individuals with an excellent source of state of-the-art tion and, by so doing, help continue our growth and allow us to become truly interdisciplinary in nature

informa-Joseph J Hurrell, Jr., PhD,

Editor, Journal of Occupational Health Psychology

xviii Foreword

Occupational health psychology has arrived! Our discipline has lished healthy professional organizations such as the Society for Occu-pational Health Psychology (SOHP) and the European Academy of Occupational Health Psychology (EA-OHP), highly cited journals,

estab-including Work & Stress and the Journal of Occupational Health chology, and thriving professional conferences such as the Work Stress

Psy-and Health conference (sponsored by the National Institute for pational Safety and Health, the American Psychological Association, and SOHP) and the biannual conference of the EA-OHP Many doc-toral level training programs are producing graduates with OHP inter-ests (including several coauthors and reviewers of the chapters in this volume) And, observers of the job market will note both a growing interest in the particular knowledge and skill set of OHP profession-als and a steadily accumulating track record of success of OHP-trained graduates in competing for the best available jobs

year we see more and better research on occupational health—research that refl ects contributions from many scientifi c disciplines Similarly, there is been a steady growth of scholarly books on OHP including the

Handbook of Occupational Health Psychology (Quick & Tetrick, 2011), the Contemporary Occupational Health Psychology series published by Wiley-Blackwell, and the Research in Occupational Stress and Well- being series published by Sage In addition to these broad reviews, sev-

eral handbooks have focused on OHP topics such as stress (Barling, Kelloway, & Frone, 2005), safety (Barling & Frone, 2004; Hofmann & Tetrick, 2003), and workplace violence (Kelloway, Barling, & Hurrell, 2006) Further, although calls for more and better OHP-focused inter-ventions are a persistent refrain in the literature, many recent discus-sions of intervention-related topics suggest tremendous progress in this area in the last 5 to 10 years, both in terms of empirical support for

certain kinds of interventions (cf Lamontagne, Keegel, Louie, Ostry,

& Landsbergis, 2007) and in terms of understanding best practices in

Houdmont, 2007; Nielsen, Fredslund, Christensen, & Albertsen, 2006; Nielsen, Randall, Holten, & González, 2010; Scharf et al., 2008) Although there are many reasons for excitement about the develop-ment of OHP to date, we have unfi nished business OHP scholarship deals with complex problems, including interactions between person and situation factors and potentially dynamic changes in some of these factors over time Also the applied setting of OHP research oft en requires researchers to integrate multiple methods and/or levels of data

causal sequences among variables, both because critical health

con-duct ecologically valid experimental research on occupational health

by concerns about the appropriate conceptualization and ization of core OHP constructs

operational-Despite these concerns, few publications have discussed

in the literature and it is made even worse by the challenges of keeping

up with relevant methodological developments in multiple OHP-related

and make practical recommendations regarding methodological issues

in diff erent aspects of OHP research We sought a balance between chapters focused on state-of-the-art summaries of issues on topics of long-standing concern in applied psychology and topics from research-ers in other disciplines who brought their perspective to best practices

in OHP research Our goal was to help scholars by translating recent innovations in methodology into sets of useful concrete recommenda-tions to improve their own research as well as their training of future researchers

brief chapters that review measurement issues in several OHP topics

We chose these topics with a couple of goals in mind We wanted to include chapters on core OHP topics such as well-being, emotions,

intended to provide overviews of recent developments and best tices in rapidly growing areas of scholarship We also included several other chapters written by scholars who either (a) might not be regarded

prac-xx Preface

as traditional OHP scholars or (b) whose work is infl uenced by opments in related OHP disciplines With these chapters, we sought

devel-to provide scholars whose training background is more in traditional applied psychology (e.g., industrial-organizational psychology) with overviews of topics that are less likely to be addressed in their train-

stress disorder, depression and anxiety, musculoskeletal functioning, and immune system functioning

Because we wanted the chapters in the fi rst section to be brief and focused on best-practices, we specifi cally asked the contributors not to include lengthy reviews of specifi c studies utilizing each method In each case, we provided the authors with several questions related to their particular construct, process, or system, including: What are the common research questions/applications of this measurement strategy/data source in the OHP context? What are the various kinds of avail-able options for measurement in this area? What kinds of decisions/issues should a researcher consider before embarking on study using this measurement strategy/data source? And, what diff erentiates out-standing studies that use this measurement strategy/data source from

of emphasis on these questions, as appropriate to the topic; we expect readers to benefi t tremendously from the guidance provided by the authors in these chapters

design and statistical issues in OHP Some chapters review widely used approaches, such as experimental, longitudinal, and multilevel design/analyses, as well as survey sampling and self-report methods Other chapters address data sources and research strategies that, in our view, have been underutilized by OHP scholars; these chapters include archi-val research and person-centered methods, event sampling, and quali-tative research As with the measurement chapters, we asked authors to address best practices with respect to their particular topic We asked them to review, summarize, and integrate the literature on their chap-ter topic in relation to OHP research and to provide clear guidance and recommendations regarding practicing the research methods they dis-cuss As with the measurement chapters, we asked authors to consider some general questions about their topic, including: what are the impli-cations of your chapter for constructing better theories in OHP? Do issues discussed in your chapter raise any particular concerns/require-ments about samples? And, what are the common mistakes researchers Preface xxi

make when dealing with issues covered by your chapter? We hope ers will fi nd these chapters to be authoritative and informative reviews that will help them design better studies and more eff ectively and criti-cally analyze research fi ndings.

read-References

Washing-ton, DC: American Psychological Association

Oaks, CA: Sage

organizational-level work stress interventions: Beyond traditional methods Work & Stress, 21,

348–362

Hofmann, D A., & Tetrick, L E (Eds.) (2003) Health and safety in organizations: A

multilevel perspective San Francisco, CA: Jossey-Bass

Kelloway, E K., Barling, J., & Hurrell, J J, (Eds.) (2006) Handbook of workplace

vio-lence Th ousand Oaks, CA: Sage

Lamontagne, A D Keegel, T., Louie, A.M., Ostry, A., & Landsbergis, P.A (2007) A systematic review of the job-stress intervention evaluation literature, 1990–2005

International Journal of Occupational & Environmental Health, 13, 268–280.

Nielsen, K., Fredslund, H., Christensen, K B., & Albertsen, K (2006) Success or

fail-ure? Interpreting and understanding the impact of interventions Work & Stress,

20, 272–287.

Nielsen, K., Randall, R., Holten, A., & González, E R (2010) Conducting

organiza-tional-level occupational health interventions: What works? Work & Stress, 24,

We have many people to thank for their help with this book All three of

us are grateful for the love and support of our families, without whom our own work would be much less healthy We also wish to express our appreciation to Anne Duff y and her staff for their support throughout the publication process Of course, this would not be a book without the contributions of all of the chapter authors; one of the great things about doing work in Occupational Health Psychology is the people you meet—we are truly fortunate to have had the opportunity to work with

an incredible group of scholars, and we thank them all for their work, as well as their patience with and responsiveness to the editorial process Finally, we wish to think all of the graduate students who helped us with

Sears, Crystal Burnette, Chad Peddie, Le Zhou, Melissa Waitsman,

the book, and we look forward to seeing them as members of the next generation of leaders in the science and practice of occupational health psychology

Part I

Measurement

Measurement of Immune System

Functioning

Bengt B Arnetz and Matthew Ventimiglia

Immune System Functioning and Occupational Health

Psychology

Mind–Body Connections

of many research studies It is well documented that psychological cesses have a signifi cant impact on health Within the occupational health psychology domain, numerous studies have reported associa-tions among workplace stressors, unemployment, and adverse mental, somatic, and social health eff ects (Arnetz et al., 1987; Grawitch, Trares,

pro-& Kohler, 2007) In order to further develop the science and tion of occupational health psychology, it is important to enhance our understanding of the causal biological links between workplace stress-ors, resiliency factors, and health Such knowledge will inform theo-retical models and off er a complimentary means to evaluate workplace interventions

applica-Psychological stress, including occupational stress, has been widely linked to altered immune functioning, and thus is an important fac-tor to consider when assessing possible contributors to poor physical health (Meijman, von Dormolen, Herber, Rogen, & Kuioer, 1995; Zeier, Brauchi, & Joller-Jemelka, 1996) Occupational health psychologists should consider the bilateral relationship between the central nervous system and the immune system Not only does the brain infl uence the immune system; the immune system infl uences the brain For example, activation of proinfl ammatory parts of the immune system due to viral

4 Bengt B Arnetz and Matthew Ventimiglia

and bacterial infections or autoimmune disorders, such as rheumatoid disease, commonly induces “feeling sick” and “sickness behavior” (Rief, Hennings, Riemer, & Euteneuser, 2010) Sickness behavior is character-ized by loss of energy, social withdrawal, and impaired cognitive func-tioning, which can ultimately aff ect performance at work

feedback loop which includes the neuroendocrine, metabolic, and cardiovascular systems and involves cognitive, emotional, behavioral, and social processes (Howk & Bennett, 2010; McEwen, 1998) In this chapter, we briefl y review the role and structure of the immune sys-tem and discuss some common, readily available, feasible, and reason-ably priced measures of immune system functioning Furthermore, the chapter will discuss sampling considerations and other methodological issues researchers need to consider prior to choosing specifi c immune markers

The Role and Structure of the Immune System

applicable to occupational health research to monitor the functionality

of the respective layer of the immune system Table 1.1 summarizes the various immune markers, what part of the immune system they repre-sent, and means to sample bodily fl uids to determine the concentration and function of these markers

Mechanical Barrier

Surface barriers, such as skin, act to prevent pathogens from entering

additional means to defend against pathogens Coughing and sneezing mechanically eject foreign particles from the respiratory tract Mucus secreted by the respiratory and gastrointestinal tracts traps and ejects pathogens Flushing of tears and urine also facilitates the expulsion of pathogens

8 Bengt B Arnetz and Matthew Ventimiglia

Chemical Barrier

skin and respiratory tract secrete antimicrobial proteins (e.g., sins) Additionally, enzymes such as lysozyme and phospholipase A2

ß-defen-in saliva, tears, and breast milk are also part of the chemical defense system against pathogens

Further, salivary alpha-amylase is a salivary enzyme, which is secreted by the salivary glands Similar to salivary IgA, salivary amy-lase is a part of the oral mucosal defense system, the major function of which is to thwart the growth of antigens High levels of amylase have been reported to be linked to activation of the sympathetic nervous sys-

which decreases immune functioning

The Innate Immune System

once microorganisms or toxins have successfully entered the body Cell-mediated immunity is an important part of this defense system

It depends on the activation of cytotoxic T-lymphocytes, natural killer

innate response is triggered when pathogens are recognized by the body, or by damaged cells that send out chemical stress signals

to defend the body against a vast array of diff erent pathogens ness and swelling and signs of infl ammation are caused by increased blood fl ow to infected and damaged tissue Increased blood fl ow and increased temperature (fever) in the aff ected body region enhances the

is caused by specifi c immune factors released from the damaged cells Infl ammation is further promoted by the release of eicosanoids, such as prostaglandins which produce fever and dilation of blood vessels, and leukotrienes that attract certain white blood cells Damaged cells also release cytokines, including interleukins, such as interleukin 6 (IL-6), IL-8, and tumor necrosis factor-α, that are responsible for communica-tion between white blood cells; chemokines that promote the migra-tion of defensive white blood cells to aff ected tissue, and interferons with antiviral properties Interleukins also stimulate the production

Measurement of Immune System Functioning 9and release of C-reactive protein (CRP) from the liver; an important component of the innate immune system CRP, popular in psychoneu-roimmunologic research, is a reliable prognostic marker for future car-diovascular disease (Ridker, Hennekens, Buring, & Rifai, 2000) Concomitantly with the activation of the infl ammatory process, the repair system is activated to accelerate recovery from damage caused

important role in regulating the initial immune response, but also restore the system to the status quo following an infection Insulinlike growth factor (IGF)-1 is also an important anti-infl ammatory peptide, which might decrease during severe stress (Cankaya, Chapman, Talbot, Moynihan, & Duberstein, 2009)

innate immune system It contains more than 20 diff erent proteins, which “complement” other systems in the killing of pathogens to pro-

anti-bodies that are already attached to pathogens that the body wants to

carbohydrates on the surface of pathogens It contains enzymes, ases that destroy the structure of pathogens and also attract additional

important cascade system promoting the migration of immune cells

to damaged tissue, increasing vascular permeability to ensure cellular

also marks the surface of pathogens for destruction by other immune system components

Cellular Barriers

White blood cells, or leukocytes, are an additional aspect of the innate immune system White blood cells are part of the cellular (or cell-medi-

phagocytes, which include macrophages and neutrophils; mast cells

phagocytosis (consumption) of pathogens is an important feature of the innate immune system Phagocytes constantly circulate in the body

cytokines released from infected cells

10 Bengt B Arnetz and Matthew Ventimiglia

Adaptive Immune System

response to pathogens and also generates immunologic memory cifi c “memory cells” maintain a memory of the pathogen, which allows for an eff ective and speedy removal of the pathogen should it reappear

and lymphocytes Granulocytic cells consist of neutrophils which destroy bacteria; eosinophils which engulf antigen-antibodies and also defend against some parasites; and basophils which aid in infl amma-tion and reaction to allergens

Monocytes originate in the bone marrow and are able to move

the ability to divide into macrophages and dendritic cells Dendritic cells are phagocytes that are located in tissue that are in contact with

antigens to T cells, part of the adaptive immune system

Lymphocytes, one of the most important cells in the immune defense system, consist of natural killer cells (NK), T cells, and B cells NK cells are a part of the innate immune system, which is present

at birth, and are crucial in defending the body from both tumors and virally infected cells T cells are involved in cell-mediated immunity whereas B cells are primarily responsible for humoral immunity, pro-

responses that are tailored to maximally eliminate specifi c pathogens

or pathogen infected cells B cells respond to pathogens by dividing into plasma cells that secrete a large number of identical antigen-specifi c

antibod-ies bind to the specifi c antigen (pathogen) and mark them either for destruction by phagocytes or for destruction by the complement system

In response to pathogens, some T cells (i.e., T helper cells) produce kines that direct the immune response while other T cells (cytotoxic T

are numerous subtypes of T lymphocytes One type, CD4+ T cyte is of special interest in psychoneuroimmunologic research since

lympho-it has been shown to have prognostic validlympho-ity in HIV poslympho-itive patients When B and T cells have been activated and begin to divide, some

Measurement of Immune System Functioning 11

“remember” specifi c antigens (pathogens) and react promptly should they reenter the body Similarly, this same response is achieved by

as the concentration of specifi c antibodies, is weakened in response to intense and sustained stress

Infl ammation

Infl ammatory markers are strongly associated with cardiovascular disease, the leading cause of death in most developed countries, as well as Type 2 diabetes, arthritis, osteoporosis, Alzheimer’s disease, periodontal disease, some cancers, frailty, and functional decline (Kiecolt- Glaser, 2009) Markers of infl ammation include serum levels

of interleukin (IL)-6 and other proinfl ammatory cytokines (e.g., IL-8) Stress and negative emotions such as anxiety and depression enhance the production of proinfl ammatory cytokines and ultimately increase infl ammation (Sergerstrom & Miller, 2004)

Assessment of Humoral and Cellular Immune Reactions

Humoral and cellular immunity are the two main types of immune responses and can be measured with separate types of assays For humoral immune responses, available assays measure production of antibodies Cellular immune responses can be assessed through assays that measure functions of the responding T cells that occur from rela-tively early time points (major histocompatibility complex [MHC]-peptide binding, cytokine production, cytotoxicity) to later time points (proliferation) in the T cell activation process

Enumerative Immune Assays

Immunoassays can also be diff erentiated by two classes: enumerative and functional Enumerative assays consist of measures which assess the quantity or percentage of white blood cells (leukocytes) in the peripheral blood as well as those which measure the quantity of anti-bodies (e.g., immunoglobulins) or the antibody to pathogen ratio (Her-bert & Cohen, 1993)

12 Bengt B Arnetz and Matthew Ventimiglia

Measuring the quantity of specifi c types of white blood cells in the peripheral blood is a popular method researchers use to assess immune functioning Such methods are commonly used because they are relatively simple to perform On the other hand, the quantifi cation of

to interpret For instance, a greater number of diff erent cell types does not necessarily correspond with greater immune system functioning (Stites & Terr, 1991) Additionally, there exist alternative explanations such as cell migration outside the vascular system, which may explain a change in the number of cell types featured in blood samples (Herbert

& Cohen, 1993)

Functional Immune Assays

Functional immunoassays, like enumerative assays, are performed in vitro but are diff erent in that they measure not the quantity of cer-tain immune cells, but instead the cells’ abilities to combat antigens Researchers using functional immunoassays can measure immune functioning by, for example, exposing lymphocytes to mitogens and

assess how eff ectively lymphocytes divide when stimulated by mitogens (Arnetz et al., 1987; Davis, Kozinetz, & Noroski, 2006)

Another common activity performed by functional assays is to

by incubating immune cells with tumor cells, which are natural targets

cells with higher levels of immune cells indicating better immune response Several studies have reported a link between stress, including occupational stress, and reduced NK activity and immune functioning

Dinato et al., 2006; Nakata et al., 2000)

Neuroendocrine Markers

dis-cussed earlier, the immune system is closely integrated with a number of biological systems in order to maximize the body’s ability to withstand

Measurement of Immune System Functioning 13

(SAM) system and the hypothalamic-pituitary-adrenal (HPA) axis directly infl uence important aspects of the immune system, including modulating the expression of cytokines and chemokines, with implica-tions for the infl ammatory response (Glaser, Rabkin, Chesney, Cohen,

& Natelson, 1999; Ziemssen & Kern, 2007) Neuroendocrine markers include cortisol, catecholamines, and dehydroepiandrosterone

Cortisol

Cortisol, the main stress hormone released from the HPA axis, is cal in the acute stress response (Ekman & Arnetz, 2006) Sustained HPA activation and thus higher prolonged concentration of cortisol and other glucocorticoids result in a number of pathological changes, however, including suppressed immune response Glucocorticoids can enhance amygdala activity, heighten fear conditioning, and dam-age neurons, especially in the prefrontal cortex and the hippocampus (Charney, 2004; Makino, Gold, & Shulkin, 1994; Shepard, Barron, & Myers, 2000) In particular, elevated cortisol levels have been associated with several health problems including Type 2 diabetes, cardiovascular disease, cognitive impairment, and overall suppressed immune func-tioning Cortisol can be measured in blood, saliva, and urine Increas-ingly, assessment of free cortisol in saliva is used in occupational stress research (e.g., Groer et al., 2010; Rystedt, Cropley, Devereux, & Michal-ianou, 2008) However, glucocorticoids show substantial circadian variations; they respond to sleep deprivation, alcohol and other com-monly used drugs, as well as lifestyle factors, including exercise and nutritional habits Circadian variations can be controlled by restricting

stud-ies, and it is especially important when individuals are followed over time Switching from daylight saving time to standard time might also impact the validity of glucocorticoids in longitudinal studies

Catecholamines

Catecholamines such as epinephrine (adrenaline) and norepinephrine (noradrenaline) are secreted by the SAM system in response to stress Higher levels of catecholamines have been linked to health problems,

14 Bengt B Arnetz and Matthew Ventimiglia

such as cardiovascular disorders including higher blood lipid levels, increased blood clotting, atherosclerosis, hypertension, and myocardial infarction In occupational health research, catecholamines are typi-

though much more complex, is to sample catecholamines from arterial blood Concentration of catecholamines in arterial blood is a valid rep-resentation of the actual peripheral tissue exposure to stress hormones However, blood levels of catecholamines typically vary considerably over a short period of time

Dehydroepiandrosterone

Dehydroepiandrosterone (DHEA) counteracts the eff ects of ticoids in general, and cortisol in particular DHEA is also neuropro-tective During short-term stress, DHEA secretion is increased along with cortisol Sustained stress results in decreased DHEA levels, which hampers restorative processes and accelerates aging Dehydroepian-drosterone-sulphate can be easily measured either in blood or saliva

glucocor-Considerations in the Selection of Immune System Markers

occupational health research is, naturally, the overall objective of the study Is the topic of interest short-term stress or sustained stressor exposure? For short-term stress, CRP, immunoglobulins, and inter-leukins are excellent indicators of altered immune responses For lon-ger term stress, changes in cytoxic T-lymphocytes and cell-mediated immunity are excellent additions When the focus is on specifi c dis-ease processes (e.g., occupational stress and the risk for cardiovascu-lar disease), infl ammatory markers such as CRP are more relevant Is the design cross-sectional or longitudinal? All of these questions are important since they have an impact on the choice of immune mark-ers As discussed above, certain immune markers respond quickly to stress, while others could take days or weeks to respond Another issue

of great concern is the clinical validity of changes in immune eters Apart from CRP and, in the case of HIV positive persons, CD4+

param-T lymphocytes, there are few immune systems changes observed ing everyday stress that are truly linked to future morbidity or mortal-

Measurement of Immune System Functioning 15occupational health psychology researchers devote to the psychometric properties of psychological scales

immune markers from which to choose In controlled laboratory tings, or with infrequent sampling in naturalistic settings, blood sam-ples are feasible In workplace settings, saliva or collecting blood using blood spots (small sample of whole blood dried on fi lter paper) is more functional and acceptable Saliva sampling for salivary IgA, lysozyme, CRP, or other biomarkers is a relatively convenient, eff ective, and easy method However, saliva sampling does not allow for the assessment

set-of other important biomarkers (e.g., white blood cell functioning) whereas blood samples are able to provide data regarding leukocytes, the complement system, leukotrienes, and ultimately a bigger picture of the immune system and its functioning as a whole

Saliva or Blood

Many of the measures needed to assess the immune system require the collection of blood Venipuncture is invasive, potentially anxiety pro-voking, and relatively costly since it must be performed by a trained phlebotomist Samples also need to be promptly processed and stored

and today we can measure CRP and Immunoglobulin A in saliva We can also determine concentrations of a range of pathogen defense fac-tors in saliva and tears; for example lysozyme and phospholipase A2 Saliva can also be used to measure DHEA and cortisol Saliva is col-lected by having the participant place a cotton salivette dental swab in

is subsequently returned to a tube and frozen until further analysis Alternatively, tubes with saliva swabs can be shipped to the lab by over-

long-term and workplace based studies

Another important consideration is cost Saliva sampling and analysis is very cost-eff ective, particularly when compared to blood analysis Unfortunately, saliva-based sampling does not allow for the measurements of more advanced immune functions Increasingly the functional capacity of the immune system, for example, the ability of lymphocytes to react to pathogens, is of importance to assess the pos-sible health impact of sustained stress, or exposure to pathogens