Definition and Background

Three broad traditions of assessing the role of stress in disease risk can be distinguished. The environmental tradition focuses of assessment of environmental events or experiences that are normatively (objectively) associated with substantial adaptive demands. The psychological tradition focuses on individuals’ subjective evaluations of their abilities to cope with the demands posed by specific events or experiences and their affective response to that evaluation. Finally, the biological tradition focuses on activation of specific physiological systems that have been repeatedly shown to be modulated by both psychologically and physically demanding conditions. We will focus on the first two approaches here.

In addressing the environmental tradition, we will discuss questionnaire and interview measures of major stressful life events, measures of chronic stress, as well as measures of daily events. In addressing the psychological tradition, we will discuss measures of perceived stress and of negative affect. The reader is referred to the volume edited by Cohen, Kessler and Underwood Gordon (1995) for detailed descriptions of measurement issues and measures for each of these approaches.

Measurement

Checklist measures of major life events. Major stressful life events instruments ask respondents to report which of a list of events (ranging from 10 to 200) happened to them in a specific time line, usually the last year. The events on the list are supposed to be representative of the population of major stressful life events that occur in people’s lives. Examples of events include: death of a loved one, loss of a job, being divorced, moving, and going to court. In general, the idea of life events instruments is that whatever major events do to us (e.g., require adaptation, induce negative affect and cognition), this accumulates as the number of events accumulate. The more events, the greater the stress. Some scales make explicit assumptions about the underlying cause by weighing events on certain dimensions instead of just counting the number of events. Examples of such dimensions include: the amount of adaptation required as determined by objective judges and the negative impact of each event as weighted by the respondent or in some cases by judges. Weighting schemes, no matter what there underlying assumptions, have not proven to add substantially to the prediction of either mental or physical health outcomes.

Many of the studies of stressful life events and health have used the Schedule of Recent Experiences, an instrument developed in the mid 1950s, or the Social Readjustment Rating Scale, an elaboration of this instrument developed by Holmes & Rahe in the mid 1970s. These instruments are not considered state-of-the-art at this time. A detailed history of the evolution of major stressful life event scales can be found in Cohen, Kessler and Underwood Gordon (1995; Chapter 1) and Wheaton & Turner (1995). Moreover, a reader planning to use a life events instrument is strongly encourage to read Wheaton & Turner’s (1995) detailed discussion of issues in measuring stressful life events. There are a range of complex questions involved that cannot be address in this forum.

There is no life event instrument that is appropriate for all populations or one that is generally accepted in the field. An instrument often used in large general population surveys is the PERI life events scale (Dohrenwend et al., 1982). List of major life events scales designed specifically for various populations, e.g., children, adolescents, adults, and the aged, are provided by Wheaton and Turner (1995). As discussed earlier, an appropriate scale is supposed to have items that represent the population of events that occur in the population under study. This raises questions about the sensitivity (appropriateness) of any of the standard life events instruments for those studying lower SES, or specific ethnic populations.

Interview measures of major life events. Intensive personal interview measures use qualitative probes in order to specify more precisely the characteristics of life events believed to produce stress. There are a number of differences between interview measures and checklist measures. Most importantly, the two validated interview techniques are designed to elicit reports of specific events that put people at risk for disease rather than taking the "cumulative" measurement approach of the checklist measures. This allows the investigator to identify specific types of stressors that put people at risk (e.g., specific domains, or durations). Although they provide a much richer description of the nature of stressful events in persons’ lives and have better psychometric characteristics (both validity and test-retest reliability), interviews are time consuming (for both respondent and interviewer), expensive, and require training of interviewers and in some cases raters as well. The reader is encouraged to read Wethington, Brown & Kessler (1995) for detailed descriptions of available interview measurement techniques.

There are two major interviews: The Life Events and Difficulties Schedule (LEDS), and the Standardized Event Rating System (SEPRATE). The LEDS diverges from other life stress measures in providing consensually-defined contextual ratings of threat. For example, although loss of employment receives a uniform score within many checklist approaches, the LEDS differentiates leaving an unsatisfying job because of lack of financial need from being fired following twenty years of dedicated and fulfilling service. Raters who are blind to the individual's subjective response to an event are provided with extensive information regarding each event and the context in which it occurred, and then rely on thorough "dictionaries" of precedent examples to rate several scales, including long-term threat, timing of the event (onset and offset), and extent to which the event is focused on S or others. The dictionary ratings are based on the likely response of an average person to an event occurring in the context of a particular set of biographical circumstances.

The primary scores from the LEDS are based on whether an acute or chronic stressful event was experienced during the last year. In LEDS terminology, acute events are termed "events" and chronic stressful conditions are termed "difficulties". Events have durations of less than a month, while difficulties last more than a month. Events and difficulties that are thought to play a role in health are those that are rated by the judges as having marked or moderate long-term threat.

Unlike the LEDS, the SEPRATE attempts to identify objective events independent of the situational and individual characteristics that determine individual vulnerability. The SEPRATE is derived from the PERI life events checklist (see above) and consists of a series of yes/no questions regarding 84 types of events or difficulties that may have occurred and been severely stressful (Dohrenwend et al., 1993). Each "yes" answer is probed with a number of structured questions. The purpose of the probes is to provide a narrative description of each event and to produce a standardized assessment of separate aspects of situations thought to produce the experience of stress. These assessments include magnitude of change brought about by the event, desirability of the event (from the "average" perspective), disruptiveness to daily life routines, threat to life, fatefulness (occurrence independent of respondent control), etc. Narratives of each event that strip them of any material that might be used to infer "social vulnerability" are prepared. The narratives are then rated by two independent raters on the dimensions mentioned.

Chronic stress measures. Major stressful life checklists often contain both relatively acute and chronic events. On the other hand, the interview techniques allow one to distinguish between acute and chronic stressors, but are often impractical in studies of large samples. There have been attempts, however, at questionnaires designed specifically to assess chronic stress in important role domains, e.g., work and marriage. The reader is referred to Lepore (1995) for a detailed discussion of these measures.

It is probably inappropriate to include existing chronic stress measures in the section on environmental sources of stress since the vast majority of these questionnaires are self-report and ask about perceptions of aspects of a specific social role that may be stressful. In the work domain there are many fairly reliable and multidimensional measures of role stressors (e.g., WES; Moos, 1981; OSI; Osipow & Spokane, 1987; and JCQ; Karasek, 1985). Questionnaires in the marital domain include the FES (Moos & Moos, 1981), the MSI (Smolen et al., 1985), the ENRICH (Fournier et al., 1983), and the MAP (Notarius & Vanzetti, 1983). The work stressor questionnaires typically include items or scales related to role conflict, quantitative and qualitative demands or overload, role ambiguity, lack of control or autonomy, lack of support or cohesion, inadequate career opportunities, job insecurity, and interpersonal conflict. The marital role stressor questionnaires typically include items related to problems in communication, verbal and physical abuse, lack of emotional closeness and affection, infidelity or sexual problems, excessive role demands, or inequity in division of labor. The LEDS (described in section on Major Life Event Interviews) can be used to measure specific chronic stressors. An interview on a focused area or areas would require considerable less time in both administration and scoring than the standard LEDS.

Daily event measures. Stressful experiences on the daily level are assessed with self-report using a daily diary or record. These diaries allow the investigator to examine stress at the level of daily experiences, rather than the more encompassing events assessed with major stressful life events instruments. This can be used to tackle important theoretical problems such as the nature of chronic stress, the mechanisms through which major stressors exert their effects, and the role of personality and social structure in the stress process. The reader is referred to Eckenrode and Bolger (1995) for detailed discussion of daily events and the various measures that are available.

Depending on the situation, one of three types of assessment techniques needs to be selected: interval-contingent recording, signal-contingent recording, or event-contingent recording (see Wheeler & Ries, 1991). In interval-contingent recording, data are collected at regular intervals determined in advance by the investigator, e.g., once an hour, once every three hours, or once a day. In signal-contingent recording respondents record their experiences whenever signaled by the researcher. This is often done with beepers, electronic watches, hand-held computers, or pagers. In event-contingent reporting, respondents make a report every time a predetermined event has occurred. Choosing the appropriate measure requires consideration of the nature of the stressors and the questions the investigator in asking (refer to Eckenrode & Bolger, 1995).

There are a number of standardized daily event measures used on an interval-contingent schedule. The Daily Life Experiences Checklist (DLE) contains 78 events categorized into five domains--work, leisure, family, friends, financial, and other (Stone & Neale, 1982). Respondents are asked to rate the events that happened since they "first awoke this morning." For each checked event they also rate its desirability and meaningfulness. The diary takes about 10 minutes to complete. The Daily Stress Scale (e.g., Bolger & Schilling, 1991) has 22 events selected on the basis of piloting testing with married couples. Respondents are asked to check events that happened to them in the last 24 hours. Follow-up questions are also possible with this scale.

Several daily event scales have been designed as retrospective reports of "hassles" that have occurred over the last month or so. This includes the "revised" Hassle Scale (DeLongis et al., 1988), a 53-item scale that includes both undesirable (hassles) and desirable (uplifts) events and the Inventory of Small Life Events (ISLE) which contains 178 items, 98 undesirable and 80 desirable (Zautra et al., 1986). Similarly, the Daily Stress Inventory (DSI; Brantley & Jones, 1993) is a 58-item questionnaire that asks about minor events occurring in the last 2-weeks.

As with major stressful life event checklists, daily event instruments are presumed to contain items that represent the population of daily events that occur in the lives of people they sample. Many of these scales have been developed through open ended questioning of their samples. However, the question still remains whether they would be appropriate for people of low SES or those from specific ethnic communities.

Perceived stress measures. Although psychological stress theory focuses on people’s appraisal of events as threatening or challenging, there has been very little development of perceived stress measures. The reader is referred to Monroe & Kelley (1995) for an overview of measurement of perceived stress.

The Stress Appraisal Measure (SAM) was developed to assess the dimensions of primary appraisal (threat, challenge, centrality) for a specific anticipated stressor (Peacock & Wong, 1990). Unfortunately, this scale has been only used with college students and its applicability and usefulness for broader populations is questionable. However, it might provide the basis of questions for assessing appraisal of a specific stressor.

Negative affect measures. Appraisal of events as threatening is presumed to cause a negative affective response that provides the proximal link to behavioral and biological responses thought to be responsible for illness susceptibility. There has been considerable effort in the area of measuring negative affect and the reader is referred to Stone (1995) for detailed discussion of approaches and measurement instruments.

The most commonly used mood measures are adjective checklists. In this procedure, a number of adjectives representing mood states are presented and the respondents are instructed to indicate whether the presented mood reflects their own feelings. There are many variations on this basic theme, involving different response scales, different sets of adjectives, and different instruction sets. Popular scales include the 36 adjective Nowlis Mood Adjective Checklist (MACL; Nowlis & Green, 1965); the 132 adjective Multiple Affect Adjective Checklist (MAACL; Zuckerman & Lubin, 1965); the 65 adjective Profile of Moods States (POMS; McNair et al., 1971); and the 20 adjective Positive Affect-Negative Affect Schedule (PANAS; Watson et al., 1988). The choice of scales would depend on the level of differentiation one wants (e.g., separate measures of anxiety, depression, anger or just negative mood), and the theoretical approach to the structure of moods that is most consistent with research interests (see discussion by Stone, 1995).

Relationship to SES

Those with lower levels of SES report more stressful life events, although these studies have focused on lower versus higher SES and not on determining a gradient. The PSS has a nice graded relation with both education and income as do negative affect measures.

Relationship to Health

Virtually all the measures we have discussed have been associated with some kinds of health outcome measures, although in many cases this would be self-reported psychological distress or psychosomatic symptoms. However, most of the life events scales, negative affect, and the perceived stress measures have been associated with a "hard" physical disease outcome in one context or another.

Limitations

Each type of measurement procedure has its own limitations. The reader is referred to Cohen, Kessler & Underwood Gordon (1995) for discussion of these limitations. A particular issue in the context of the network is the applicability of these measures in low SES and select ethnic groups.

Network Usage

Sheldon Cohen is using the LEDS, a daily stress interview, the PSS in his work in susceptibility to colds; a major life events scale and the PSS in his work on the onset of wheezing in children at risk for asthma; and a major life events, PSS, and negative affect scale in his laboratory work on the stability of stress-reactivity over time.

Conclusions

The exact stress measure one chooses depends on the question that is being posed. For example, one could ask whether there are those with lower SES experience more or different kinds of life events, whether they perceived the same events as more threatening, or whether they respond to threat with greater negative affect? Each of these question demands a different measure. Although it is commonly thought that SES is associated with greater stress, especially chronic stressors, there is little existing evidence on the types or magnitude of stress experienced at different levels of the SES gradient.

Selected Bibliography

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Brantley, P. J., & Jones, G. N. (1993). Daily stress and stress-related disorders. Annals of Behavioral Medicine, 15, 17-25.

Cohen, S., Kamarck, T. & Mermelstein, R. (1983). A global measure of perceived stress. Journal of Health and Social Behavior, 24, 385-396.

Cohen, S. & Williamson, G. (1988). Perceived stress in a probability sample of the United States. In S.Spacapan & S. Oskamp (Eds.) The social psychology of health: Claremont Symposium on applied social psychology. Newbury Park, CA:Sage.

Cohen, S., Kessler, R., & Underwood Gordon, L. (eds.) (1995). Measuring Stress: A guide for health and social scientists. New York: Oxford University Press.

Cohen, S., Kessler, R., & Underwood Gordon, L. (1995). Strategies for measuring stress in studies of psychiatric and physical disorders. In S. Cohen, R. Kessler, & Underwood Gordon, L. (Ed.), Measuring Stress (pp. 3-28). New York: Oxford University Press.

DeLongis, A., Folkman, S., & Lazarus, R.S. (1988). The impact of daily stress on health and mood: Psychological and social resources as mediators. Journal of Personality and Social Psychology, 54, 486-495.

Dohrenwend, B. S., Krasnoff, L., Askenasy, A. R., & Dohrenwend, B. P. (1982). The psychiatric epidemiology research interview life events scale. In L. Goldberger & S. Breznitz (Eds), Handbook of stress: Theoretical and clinical aspects. New York: Free Press.

Dohrenwend, B. P., Raphael, K. G., Schwartz, S., Stueve, A., & Skodol, A. (1993). The structured event probe and narrative rating method for measuring stressful life events. In L. Goldberger & S. Breznitz (Eds.), Handbook of Stress (pp. 174-199). New York: Free Press.

Eckenrode, J. & Bolger, N. (1995). Daily and within-day event measurement. In S. Cohen, R. Kessler, & Underwood Gordon, L. (Ed.), Measuring Stress (pp. 80-101). New York: Oxford University Press.

Fournier, D. G., Olson, D. H., & Druckman, J. H. (1983). Assessing marital and premarital relationships: The PREPARE-ENRICH Inventories. In E. E. Filsinger (Ed.), Marriage and family assessment: A sourcebook for family therapy (pp. 229-250). Beverly Hills, CA: Sage.

Holmes, T. H., & Rahe, R. H. (1967). The social readjustment rating scale. Journal of Psychosomatic Research, 11, 213-218.

Karasek, R. (1985). Job Content Questionnaire and user’s guide. Lowell, MA: University of Massachusetts.

Lepore, S. (1995). Measurement of chronic stressors. In S. Cohen, R. Kessler, & Underwood Gordon, L. (Ed.), Measuring Stress (pp. 102-121). New York: Oxford University Press.

McNair, D., Lorr, M., & Droppleman, L. (1971). Psychiatric Outpatient Mood Scale. Boston, MA: Psychopharmacology Laboratory, Boston University Medical Center

Monroe, S., & Kelley, J. (1995). Measurement of Stress Appraisal. In S. Cohen, R. Kessler, & Underwood Gordon, L. (Ed.), Measuring Stress (pp. 122-147). New York: Oxford University Press.

Moos, R. H., & Moos, B. S. (1981). Family Environment Scale manual. Palo Alto, CA: Consulting Psychologists Press.

Moos, R. H. (1981). Work Environment Scale manual. Palo Alto, CA: Consulting Psychologists Press.

Notarius, C. I., & Vanzetti, N. A. (1983)/ The Marital Agendas Protocol. In E. E. Filsinger (Ed.), Marriage and family assessment: A sourcebook for family therapy (pp. 209-227). Beverly Hills, CA: Sage.

Nowlis, V., & Green, R. (1957). The experimental analysis of mood. Technical Report, Office of Naval Research: Contract No. Nonr-668(12).

Osipow, S. H., & Spokane, A. (1987). Occupational stress inventory: Manual research version. Odessa, FL Psychological Assessment Resources

Peacock, E. J., & Wong, P.T.P. (1990). The Stress Appraisal Measure (SAM): A multidimensional approach to cognitive appraisal. Stress Medicine, 6, 227-236.

Remor, E., Penedo, F. J., Shen, B.J., and Schneiderman, N. (2006). Perceived stress is associated with CD4+ cell decline in men and women living with HIV/AIDS in Spain. AIDS Care (online).

Smolen, R. C., Spiegel, D. A., Bakker-Rabdau, M. K., Bakker, C. B., & Martin, C. (1985). A situational analysis of the relationship between spouse-specific assertiveness and marital adjustment. Journal of Psychopathology and Behavioral Assessment, 7, 397-410.

Stone, A. (1995). Measurement of affective response. In S. Cohen, R. Kessler, & Underwood Gordon, L. (Ed.), Measuring Stress (pp.148-174). New York: Oxford University Press.

Stone, A. A., & Neale, J. M. (1982). Development of a methodology for assessing daily experiences. In A. Baum & J. E. Singer (Eds.), Advances in Environmental Psychology: Environment and health (Vol. 4, pp. 49-83). Hillsdale, NJ: Lawrence Erlbaum.

Turner, R. J., & Wheaton, B. (1995). Checklist measurement of stressful life events. In S. Cohen, R. Kessler, & Underwood Gordon, L. (Ed.), Measuring Stress (pp. 29-58). New York: Oxford University Press.

Watson, D., Clark, L., & Tellegen, A. (1988). Development and validation of brief measure of positive and negative affect: The PANAS scales. Journal of Personality and Social Psychology, 54(6), 1063-1070.

Wethington, E., Brown, G., & Kessler, R. (1995). Interview measurement of stressful life events. In S. Cohen, R. Kessler, & Underwood Gordon, L. (Ed.), Measuring Stress (pp. 59-79). New York: Oxford University Press.

Wheeler, L., & Ries, H. T. (1991). Self-recording of everyday life events: Origins, types, and uses. Journal of Personality, 59, 339-354.

Zautra, A. J., Guarnaccia, C.A., & Dohrenwend, B. P. (1986). Measuring small life events. American Journal of Community Psychology, 14, 629-655.

Zuckerman, M., & Lubin, B. (1965). The Multiple Affect Adjective Check List. San Diego, CA: Educational and Industrial Testing Service.