Psychological and Behavioral Assessment

Psychological and Behavioral Assessment

Chronic pain presents two broad challenges to proper assessment: 1) pain is personal and subjective, and 2) chronic pain impacts a wide range of patient functioning. These challenges necessitate a systematic approach to the standardized assessment of multiple domains of functioning using several assessment techniques, including interviews, questionnaires, behavioral observation, psychophysiologic measurement, diary data, and reports of significant others. This chapter will begin with a brief discussion of the clinical goals of psychological and behavioral assessment of patients with persistent pain, provide a rationale and context for the use of psychological assessment in the practice of pain management, articulate recommendations for the core domains of assessment, and provide an overview of the psychological assessment process. The chapter will then provide specific information about some of the most commonly employed psychological and behavioral assessment strategies for general use across chronic pain conditions. Finally, the chapter will provide information about the assessment of chronic pain in specific populations (e.g. pediatrics, older adults, and patients with mild cognitive impairment). Disease-specific measures may also be of interest to the clinician but are not specifically covered in this chapter. Examples include the Oswestry disability questionnaire (lower back pain), Western Ontario and McMaster Universities osteoarthritis index (osteoarthritis), and the neuropathic pain scale (neuropathic pain).

Clinical Objectives

A multidimensional psychological and behavioral assessment of patients with pain can assist a multi-disciplinary pain team or treating clinician in several ways. Multidimensional assessment serves as a foundation for treatment planning and subsequent evaluation of treatment outcomes. An important outcome of the assessment process is the development of specific, measurable, achievable, relevant, and time-based patient-centered goals for treatment. Data gathered in the assessment process provide important information about patients’ pain experiences, pain treatment history, current, and past emotional and physical functioning, and beliefs about pain. Assessment allows the clinician to identify patients’ strengths and weaknesses and the factors that contribute to the development and maintenance of problems in physical, social, and emotional functioning. Psychological and behavioral assessment may also reveal the need for adjunctive psychological treatment of preexisting or emerging psychosocial difficulties that may interfere with treatment. Psychological assessment can provide information about patients’ motivation and readiness to engage in treatment and the patients’ treatment preferences. Psychological assessment can also provide data about a patients’ suitability for surgical or other invasive procedures under consideration.

A thorough assessment of a patient’s pain complaint and functioning at baseline provides an important benchmark against which the efficacy of future treatments can be measured. Assessment should not stop after the initial visit but should be ongoing throughout the treatment process. This allows for the identification of new problems, quantifies progress across domains, and facilitates the refinement or revision of treatment if necessary. Posttreatment assessment is imperative to evaluate the overall success of the treatment and the differential success of the treatment across various domains of functions such as pain intensity, social, emotional, and physical functioning.

When making a request for a psychological and behavioral assessment, it is necessary to explicitly state the reasons for the request or pose a question about the patient or his/her treatment. It is helpful for the psychologist or behavioral specialist to understand the specific question the clinician or team is trying to answer about a patient to do a thorough evaluation and provide meaningful feedback. Although any psychological or behavioral assessment should be multidimensional and include all relevant domains of function, the specific measures used and the areas of most intense focus will differ depending on the consultation question. For example, an assessment to inform a decision about appropriateness for surgical intervention would have a different focus than an assessment to determine appropriateness for psychological pain treatment.

Overview of the Psychological and Behavioral Assessment Process

Ideally, psychological and behavioral assessment of patients with chronic pain should follow a hypothesis generating and testing approach. The assessment should begin broadly; as problems are identified, the clinician can hypothesize contributing and maintaining mechanisms. The assessment process will be increasingly focused and behaviorally oriented as the hypothesized mechanisms are investigated. Generally, the assessment process begins with a standardized interview that assesses the pain complaint and patients’ physical, emotional, social, and occupational functioning. This allows for the assessment of patients’ past and present levels of functioning and the temporal association of any changes in functioning to the pain complaint. Besides the information gained in the interview, questionnaires, diaries, behavioral observations, significant other reports, and medical record information may be used as adjunct sources of information. The use of multiple adjunct measures helps avoid the biases or error associated with reliance on a single assessment strategy. Hypotheses about the factors that initiated and maintain adjustment and functioning problems are generated and refined throughout the assessment process. Ultimately, the validity of hypotheses is tested by examining patients’ response to treatment.

For example, anxiety and fear of pain have been shown to contribute to unfavorable outcomes for persons with chronic pain complaints. Significant functional disability can be associated with fear of pain and further injury, such as behavioral avoidance, muscle deconditioning because of reduced activity, muscle hyperreactivity to stress, negative and distorted cognitions about the adverse effects of activity, and psychological distress secondary to restricted access to pleasant and rewarding activities. Thus when an initial interview provides evidence of a significant decline in physical functioning and anxiety is present as described above, it becomes a reasonable hypothesis and avenue for more targeted assessment through the use of specific questionnaires, diaries, or reports from significant others (e.g. spouses or partners) to determine the extent to which anxiety is present and interacting with the pain experience. Ultimately, the assessment process should result in a model that describes the patient’s specific pain experience, explicates how that patient’s beliefs, experiences, strengths, and weaknesses have resulted in their current level of functioning across domains and provide an individualized treatment plan that uses these hypotheses to target specific factors for intervention.

Domains of Functioning

The multidimensional nature of chronic pain necessitates a broad assessment of multiple domains of functioning to provide a valid snapshot of a patient’s unique pain experience and meaningfully guide intervention strategies. A useful guide for the assessment process is the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) group consensus statement regarding the core outcome domains that should be assessed and recommended instruments for measuring those domains when evaluating the efficacy of a pain treatment.

Although originally generated to aid researchers in increasing comparability across randomized controlled studies of pain treatments, these recommendations can be useful to the clinician in guiding assessment. The IMMPACT group, which consists of recognized experts drawn from academia, government agencies, and the pharmaceutical industry, recommend assessing the following chronic pain domains: pain, physical functioning, emotional functioning, patient ratings of improvement and satisfaction with treatment, treatment-related symptoms, and adverse events, and patient disposition. Additionally, through literature review and expert consensus, the group has provided recommendations regarding specific assessment instruments within each domain applicable across various pain complaints. This same group has also developed recommendations for the future development of patient-oriented outcome measures that may provide a more sensitive and efficient assessment of the key outcome domains relevant to a comprehensive assessment of patients with pain.

Overview of Assessment Strategies

Multiple assessment strategies such as interviews, standardized questionnaires, diaries, behavioral observation, psychophysiologic assessment, and assessment of family members and significant others are commonly used to investigate and quantify the pain experience and concomitant physical and emotional functioning. Multiple, standardized assessment measures are encouraged to obtain comprehensive, valid, and reliable information.

The well-conducted clinical interview can be a rich source of information regarding a patient’s pain and pain treatment history as well as the resulting physical, emotional, behavioral, and cognitive responses. ^, The interview also provides an opportunity for clinicians to interact with a patient, to establish rapport, and to develop an impression of that patient’s receptivity to rehabilitation and treatment efforts. Interviews may be standardized or unstandardized. Even when conducting an unstandardized interview, it is useful to systematically investigate a pre-specified set of domains. ( Table 22.1 is an example of an interview structure used in the author’s [RK] comprehensive pain management clinic.)

Questionnaires and inventories provide opportunities for focused assessment of specific domains of functioning and quantifying patient responses. Because published questionnaires have typically met standards for reliability and validity, greater confidence can be placed in the information provided by these measures. Questionnaires typically permit quantification of important dimensions of the experience of pain and allow for evaluation of within-person change over time. The concurrent administration of measures of multiple domains of functioning can assist in the identification of patient relative strengths and weaknesses across these domains, such as the identification of patients who report low levels of disability and distress despite an apparently severe level of pain intensity. Questionnaires with normative data offer the added benefit of providing a comparison point for evaluating the status of the respondent relative to others with similar painful conditions or within similar demographic (i.e. age, race/ethnicity, gender) groups. Ultimately, they may provide a more efficient and cost-effective option for more intensive and time consuming interviews. Following this brief overview of psychological and behavioral assessment strategies, several questionnaires and inventories frequently employed in assessing patients with pain in the clinical setting are reviewed.

Ecologic momentary assessment (EMA) is an umbrella term for measurement tools ranging from pen and paper diaries to smartphone apps and wearable technologies that sample biomarkers and physiologic parameters. Across these different tools, EMA measures seek to measure behaviors, perceptions, and physiologic markers in real-world contexts and offer many advantages over other assessment methods. They allow for information about pain, sleep, and physical and emotional functioning to be recorded prospectively and once or more times a day, eliminating distortions associated with memory and retrospective recall. EMA measures are also thought to increase the ecologic validity of assessments, as observations and ratings occur in patients’ natural environment during real (vs. contrived) situations. Additionally, EMA measures allow for recording the temporal association between pain and other factors. For example, many sleep diaries and smartphone applications collect information about pain intensity scores prior to sleep as well as sleep quality and duration. This allows for the investigation of the relationship between pain and functioning instead of examining either factor in isolation. The composition of EMA measures can vary from those designed to assess a single domain, such as pain intensity to those that are much more comprehensive and multidimensional. Patients may already engage in self-monitoring and recording and might be using pen and paper measures, smartphone applications, or a combination of modalities. It can be useful to ask patients about self-monitoring habits and consider the implantation of EMA technologies in routine patient assessment. The use of innovative technologies such as mobile telephone apps, web-based diaries, and interactive voice response systems are increasingly being promoted as more efficient strategies for the collection of prospective information.

Advances in wearable technologies also provide an efficient and powerful strategy for collecting EMA data. Consumer grade devices (e.g. AppleWatch and FitBit) and research grade devices (e.g. SenseWear Armbands, Step-Watch 3) can measure a range of biometric data, including steps taken per day, heart rate, and duration and intensity of physical activity. Steps taken per day, and other measures of physical activity and energy expenditure, can be particularly useful metrics to capture in patients with chronic pain, as reduced physical activity levels can cause worsening of comorbidities. Additionally, evidence suggests that routine physical activity can reduce pain severity and improve quality of life and physical functioning. Subsequently, wearable technologies can provide both clinicians and patients with objective measures of important modifiable health behaviors.

Behavioral observation is a useful adjunctive to self-report. Although pain is a private, subjective experience, it is possible to observe signs that patients are experiencing pain by direct behavioral observation. Patients can communicate that they are experiencing pain and the intensity of the pain through facial expressions, crying, moaning, limping, guarding, and rubbing affected areas. Behavioral observation of patients with chronic pain can provide valuable adjunct information beyond that gathered using a self-report format and is crucial to the evaluation of patients with cognitive or physical limitations that interfere with verbal communication. Behavioral observation methods have been developed to assess patients with a range of painful medical conditions, including cancer pain, rheumatoid arthritis, osteoarthritis, and low back pain. Prkachin and his colleagues reported on a method for assessment of pain behaviors in the context of a clinical evaluation of patients with low back pain. These methods have also been developed and used in studies of pain-relevant communication in partner dyads. To obtain reliable and valid behavioral observation data, it is necessary to have a systematic plan for behavioral observation, coding, and interpretation of the data; thus the use of these methods requires considerable technological sophistication and expense. The use of behavioral observation methods is commonly limited to the clinical research setting because of the time-intensive and costly nature of these methods.

The reports of families and significant others in the assessment of pain have been strongly encouraged in contemporary models of pain, particularly Fordyce’s operant conditioning model, and Turk’s cognitive behavioral model, which have specifically encouraged this focus given hypothesized roles of social contingencies in the perpetuation, if not etiology, of persistent pain and disability and the awareness of the frequent negative impact of persistent pain on significant others. In particular, the role of solicitousness in the development and maintenance of pain related disability has been a topic of a great deal of research. Operant principles specify that when spouses provide solicitous responses to pain behaviors, the pain behaviors are more likely to be emitted in the future, even in the absence of continued nociception. Positive or solicitous responses from spouses and family members, contingent on pain behaviors, may reinforce these maladaptive behaviors and encourage the development and maintenance of pain and pain related disability. Examples of solicitous behavior examined in the literature include expressions of sympathy or concern for the spouse, physical assistance or performance of a task, and encouraging rest and discouraging activity. In general, spouse solicitousness is significantly related to greater pain intensity, greater frequency of pain behaviors, higher levels of disability, and increased help-seeking behaviors. ^, Distracting responses from significant others, meaning responses that are intended to cue engagement in other behaviors in an effort to distract from pain, have been found to be positively related to poor outcomes despite the likely intent of these responses to encourage adaptive coping with pain. In addition to global measures of family and marital relationships, numerous questionnaires and inventories, diaries, and behavioral observation methods have been developed specifically for the assessment of pain-relevant communication and the impact of pain on family members and significant others.

Psychophysical measures are primarily used to demonstrate the influence of psychological factors on the initiation and maintenance of pain symptoms. For clinicians, psychophysical measures provide evidence that psychological factors are influencing biologic reactions in an individual patient and provide information regarding the utility of certain types of interventions (e.g. biofeedback). For patients, evidence that psychological factors are influencing physical responses related to pain can provide direct feedback regarding the successful use of behavioral strategies to manage a pain disorder and increase confidence to engage in these behavioral strategies.

The most common clinical use of psychophysical measures in the treatment of pain primarily occurs during biofeedback treatments. Biofeedback treatments utilize psychophysical measures to train patients in voluntary modifications of bodily reactions through the provision of feedback of physiologic processes. Surface electromyographic (EMG) recordings are the most widely used psychophysical measure in biofeedback for pain disorders because muscle tension is implicated in most musculoskeletal pain disorders. EMG readings typically target specific muscle groups associated with the patient’s pain disorder (e.g. trapezius muscle for patients with upper back pain and the erector spinae muscle for patients with lower back pain). Additionally, abnormal blood flow is linked to several chronically painful conditions, including migraine headaches and Raynaud’s disease. For these conditions, measures of blood flow and peripheral skin temperature (a proxy for peripheral circulation) can be used in biofeedback treatments.

In recent years, heart rate variability (HRV) has risen in prominence as a well validated psychophysical biofeedback measure. HRV, a measure of the duration of time between consecutive heartbeats, is an important indicator of autonomic nervous system functioning and reflects the balance in the parasympathetic and sympathetic nervous systems. Increased HRV generally indicates more adaptive physiologic reactions to environmental stressors. However, it should be noted that pathologic abnormalities in the heart’s conduction system can also increase HRV. Assuming healthy cardiac functioning, HRV provides a powerful biofeedback measure, especially for patients with chronic pain, as multiple chronic pain conditions including fibromyalgia, chronic lower back pain, and migraine have been associated with reduced HRV in the literature. ^{, ,} Preliminary pilot studies have suggested that HRV biofeedback is an effective biofeedback treatment for chronic pain. ^{, ,}