ASSESSING PAIN:Self-Report Methods, Behavioral Assessment Approaches

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Health Psychology PSY408

Lesson 25

ASSESSING PAIN

To summarize our previous lecture, the process by which people perceive pain involves a complex chain of

physiological and neuro-chemical events. These events can be affected by psychosocial processes, such as

people's beliefs about whether a drug will reduce their discomfort.

Pain also affects and can be influenced by people's learning, cognition, social experiences, and emotion.

Although people can indicate through their behavior that they are feeling pain, the pain they perceive is

actually a private and subjective experience.

How can researchers and clinicians who work with patients who have painful symptoms assess the level and

type of pain these individuals perceive? We will be answering this question in this lecture.

Assessing People's Pain

Researchers and clinicians have developed a variety of techniques for assessing people's pain. Although

virtually all these methods can be applied both in research and in treating pain patients, some techniques are

used more often in research, whereas others are used mostly to supplement a detailed medical history in

clinical practice. In either setting, it is advisable to use two or more different measurement techniques to

enhance the accuracy of the assessment. We will organize our discussion of techniques for measuring

people's pain by classifying them into three groups: self-report methods, behavioral assessment approaches,

and psycho-physiological measures.

1. Self-Report Methods

Perhaps the most obvious approach to measuring people's pain is to ask them to describe their discomfort,

either in their own words or by filling out a rating scale or questionnaire. In treating a patient's pain, health

care workers ask where the pain is, what it feels like, how strong it is, and when it tends to occur. With

chronic pain patients, medical and psychological professionals often incorporate this kind of questioning

within the structure of a clinical interview.

A. Interview Methods in Assessing Pain

To treat chronic pain effectively, professionals need more information than just a description of the pain.

Interviews with the patient and key others, such as family members and coworkers, provide a rich source of

background Information in the early phases of treatment. These discussions ordinarily focus on such issues

as:

· The history of the pain problem, including when it started, how it progressed, and what approaches have

been used for controlling it.

· The patient's emotional adjustment, currently and before the pain syndrome began.

· The patient's lifestyle--recreational interests, exercise patterns, diet, and so on--before the pain condition

began.

· The pain syndrome's impact on the patient's current lifestyle, interpersonal relations, and work.

· The social context of pain episodes, such as happenings in the family before an attack and how family

members respond when the pain occurs.

· Factors that seem to trigger attacks or make them worse.

· How the patient typically tries to cope with the pain.

The information obtained in these interviews can also be supplemented by having the patient and key

others fill out questionnaires.

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B. Pain Rating Scales

One of the most direct, simple, and commonly used ways to assess pain is to have individuals rate some

aspect of their discomfort on a scale. This approach is used very often to measure how strong the pain is.

Because rating scales are so easy and quick to use, people can rate their pain frequently. Averaging these

ratings across time gives a more accurate picture of the pain the person generally experiences than individual

ratings do. Repeated ratings can also reveal how the pain changed over time, such as during everyday

activities or during the course of an experiment. One use of repeated ratings is in showing the ebbs and

flows of pain intensity that patients often experience.

For instance, one patient's wife believed that her husband was experiencing incapacitating and severe pain

every waking hour of his life. This belief contributed to her preventing him from participating in any but the

simplest chores around the house. Their social life had deteriorated, and the couple had grown increasingly

depressed over the course of 4 years. Upon hearing that her husband experienced only moderate pain most

of the time, that he indeed felt capable of various tasks, and that he actually resented his wife's efforts at

pampering him, she was helped to alter her behavior.

Repeated ratings during each day may also reveal patterns in the timing of severe pain. Is the pain most

severe in the evening, or on certain days? If so, are there some aspects of the environment that may be

responsible and perhaps changeable?

C. Pain Diaries

Pain ratings can also be used in a pain diary, which is a detailed record of a person's pain experiences. The

pain diary a patient keeps would include pain ratings and information about the time and circumstances of

pain episodes, any medications taken, and comments about each episode.

D. Pain Questionnaires

Pain is only partly described by the intensity of the discomfort people feel--the experience of pain has

many qualities and dimensions. Ronald Melzack began to recognize the multidimensional nature of pain

through his interactions with pain patients. He described in an interview how this realization emerged from

talks he had with a woman who suffered from phantom limb pain. She would describe burning pains that

were like a red- hot poker being shoved through her toes and her ankle. She would cry out from the pain in

her legs. Of course, there were no legs. Well, that made me realize the utter subjectivity of pain-- no

objective physical measure is very likely to capture that.... I began to write down the words she used to

describe her pain. I realized that the words describing the emotional-motivational component of her pain--

"exhausting, sickening, terrifying, punishing--were very different from those for the sensory component---

shooting, scalding, splitting, cramping." Later I came to see there was also an evaluative component such as

"it's unbearable" or "it's annoying". I wrote down the words other patients used, too, but I didn't know

what to do with them.

Melzack determined that pain involves three broad dimensions--affective (emotional-motivational), sensory

and evaluative--by conducting a study in which subjects sorted over 100 pain-related words into separate

groups of their own making.

Melzack's research also indicated that each of the three dimensions consisted of sub-classes. For instance,

the sensory dimension included a sub-class with the words "hot," "burning," scalding' and "searing"--

words relating to temperature. Notice that these four words connote increasingly hot temperatures, with

searing being the hottest. Similarly, the affective dimension included a subclass of three words relating to

fear: "fearful," "frightful," terrifying." Then, by determining the degree of pain reflected by each word,

Melzack (1975)--a professor at McGill University--was able to construct an instrument to measure pain.

This test is called the McGill Pain Questionnaire (MPQ).

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2. Behavioral Assessment Approaches

Because people tend to exhibit pain behaviors when they are in discomfort, it should be possible to assess

their pain by observing their behavior. A person is likely to show different types and patterns of behavior if

the pain is intense as compared to moderate; if it involves a headache as opposed to low back pain; and if

chronic pain is recurrent than if it is intractable. Psychologists have developed procedures for assessing pain

behavior in two types of situations: in everyday activities and in structured clinical sessions.

A. Assessing Pain Behavior in Structured Clinical Sessions

Procedures are available whereby health care workers can assess the pain behavior of patients in structured

sessions that are usually conducted in hospital settings. They are structured by the specific pain behaviors to

be assessed and the tasks the patient is asked to perform. One approach of this kind has been developed

into a pain assessment instrument-- the UAB Pain Behavior Scale--for use by nurses during their standard

routines, such as in early morning rounds. The nurse has the patient perform several activities and rates

each of 10 behaviors, such as the patient's mobility and use of medication, on a 3-point scale: "none,"

"occasional," and "frequent." These ratings are converted into numerical values and summed for a total

score.

Some studies using structured clinical sessions have focused on assessing discomfort in individuals suffering

from low back pain. Each investigation had patients perform a standard set of activities. In one study, for

example, the people were asked to walk, pick up an object on the floor, remove their shoes while sitting,

and perform several exercises, such as trunk rotations, toe touching, and sit-ups. Patients in each

investigation were videotaped, and trained assessors rated their performance for several pain behaviors,

such as guarded movement, rubbing the pain area, grimacing, and sighing. These studies have shown that

pain behaviors can be assessed easily and reliably and that behavioral assessments correlate well with

patients' self-ratings of pain.

B. Assessing Pain Behavior in Everyday Activities

How does the pain patient behave in everyday activities especially at home? Does the person spend much

time in bed, complain of discomfort a lot, seek help frequently in moving, or walk with a limp most of the

time? How much of these behaviors do the person exhibit? Behavioral assessments of everyday activities

like these can be made.

Family members or key others in the patient's life are usually the best people to make these everyday

assessments of pain behavior. These people must, of course, be willing to help and be trained to make

careful observations and keep accurate records.

Researcher Wilbert Fordyce (1976) has recommended a procedure whereby the assessor--say, the client's

spouse--compiles a list of five to ten behaviors that generally signal when the patient is in pain. Then the

spouse is trained to watch for these behaviors, to keep track of the amount of time the patient exhibits

them, and to monitor how people, including the assessor, react to the client's pain behavior. This procedure

is useful not only in assessing the patient's pain experiences but in determining their impact on his or her

life and the social context that may maintain pain behaviors.

These supplemental procedures provide additional data that can be of value in dealing with interpersonal

issues that influence the pain experience.

3. Psychophysiological Measures

Another approach for assessing pain involves taking measurements of physiological activity, since pain has

both sensory and emotional components that can produce changes in bodily functions. Psychophysiology is

the study of mental or emotional processes as reflected by changes they produce in physiological activity.

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A. One psychophysiological measure researchers have used for assessing pain uses an apparatus called an

Electromyograph (EMG) to measure the electrical activity in muscles, which reflects their tension. The

findings of various researches suggest that differences between pain patients and controls may exist when

the subjects' muscles are active. And headache patients show different EMG patterns when they have

headaches than when they do not.

B. Researchers have also attempted to assess peoples' pain with measures of autonomic activity, such as

of heart rate and skin conductance.

Although some measures of autonomic activity may be useful in assessing the emotional component of

pain, they are not likely to be very useful because changes in autonomic activity also occur in the absence of

the sensation of pain.

C. The last psychophysiological measure of pain we will consider involves the electrical activity of the

brain, as measured by an electroencephalograph (EEG).

When a person's sensory system detects a stimulus, such as a clicking sound from earphones, the signal to

the brain produces a change in EEG voltage. Electrical changes produced by stimuli are called evoked

potentials and show up in EEG recordings as sharp surges or peaks in the graph. Pain stimuli produce

evoked potentials that vary in magnitude--the amplitudes of the surges increase with the intensity of the

stimuli, decrease when subjects take analgesics, and correlate with people's subjective reports of pain.

Even though psychophysiological measures provide objective assessments of bodily changes that occur in

response to pain, these changes may also be affected by other factors, such as attention, diet, and stress. In

clinical situations, measures of muscle tension, autonomic activity, and evoked potential are probably best

used as supplements to self-report and behavioral assessment approaches.

Assessing Pain in Children

When a patient has symptoms that include pain, the physician usually needs to know its location, intensity,

quality, duration, and temporal patterning. This information helps in making an accurate diagnosis.

Although children's ability to provide this information is limited, especially if they are young, researchers

have developed measures that use self-report, behavioral, and physiological methods. Effectively

interviewing children requires considerable skill in developing rapport with them, asking the right questions

in ways they can understand, and knowing what their answers mean.

What kinds of self-report methods are available to assess children's pain? One approach uses rating scales to

describe the intensity of their pain. Another approach uses questionnaires. These instruments assess the

pain itself and its psychosocial effects, such as how the child and family reacted to the pain. Adults may help

the children fill out portions of the questionnaires when they lack needed language skills.

Behavioral and physiological assessment approaches also provide valuable ways to measure children's pain,

especially in early childhood. The most obvious behavioral approach simply involves having the child or

parents report the child's pain behaviors in pain diaries. Other behavioral assessments can use structured

clinical sessions in which health care workers rate or record the occurrence of pain behavior. Methods for

physiological assessment are like those we considered earlier.

Children's pain experiences are affected by a variety of psychosocial factors, particularly the social

environment in which pain occurs. Parents serve as models and agents of reinforcement for the pain

behavior of their children. But little is known about the personality and family characteristics of children

that may contribute to the intensity and frequency of their pain. Most studies on pain have focused on adult

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subjects, not on children, and the studies conducted with children have generally produced unclear results

because they were often poorly designed and carried out. Now that researchers have methods to assess

children's pain, they can do the kind of high-quality research that is needed.

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