This article reviews how to properly assess a patient with chronic pain. A patient-centered approach includes a comprehensive history and thorough physical examination with supplemental information from diagnostic studies and psychometric instruments. The assessment is finalized using the organizational framework of four perspectives to assist in developing an individualized case formulation and treatment plan.
A common pitfall in the assessment of a patient with chronic pain is that all of the patient’s difficulties are assumed to be caused by the suffering associated with the experience of chronic pain. However, each case and the primary diagnosis, as well as comorbidities that may contribute to the overall condition, must be reviewed and examined. There is no single diagnostic test for chronic pain or each chronic pain disorder. There are numerous causes of chronic pain conditions to consider (see Table 1).
An initial functional and psychosocial assessment should be performed by the treating physician, with input from other team members. This information should verify the preliminary impression and guide the physician in the selection of laboratory, imaging, and further specialist consultations (see Table 2)
Specialized assessments, such as imaging, neurophysiologic, laboratory, and psychological tests, must be determined on a case-by-case basis
A 10-step approach to long-term chronic pain management is useful (see Table 3).
This structured approach provides a consistent and effective evaluation method. In assessing pain, the baseline descriptions and scores are important for diagnosis and for future assessment of treatment efficacy.
comprehensive evaluation includes location, duration, onset, characteristics, severity and pain goal, aggravating factors, relieving factors, and associate symptoms
treatment response measures include analgesia, adverse events, activities of daily living [ADLs], and aberrant behaviors
Patients with chronic pain suffer dramatic reductions in physical, affective, psychological, and social well being, and they rate their health-related quality of life lower than those with almost all other medical conditions.
Always assess for suicide, because this population has a suicide rate two to three times the rate of that in the general population. Sleep disturbances are a common complaint, and sleep patterns, nighttime rituals, and use of medications or substances should be addressed. Also evaluate changes in interpersonal interactions and, if possible, obtain collateral information.
There is substantial evidence that interdisciplinary pain rehabilitation programs improve functioning in several areas for patients with a number of chronic pain syndromes
Collaborative care initiatives that provide pain specialists’ assistance to primary care practitioners significantly improve pain-related outcomes
There are numerous types of psychometric testing, ranging from simple numeric scales to comprehensive questionnaires. A clinical evaluation with adjunctive psychometric testing should be part of the chronic pain assessment.
The gold standard of pain intensity is the patient’s self-report using a pain scale. The most frequently used and studied scales include the single-item visual analog scale (VAS) and the numeric rating scale.20 These scales are widely used, simple, reliable, and valid.
A decrease in pain greater than 30% reflects at least moderate improvement, and a decrease greater than 50% reflects substantial improvement.23 Documenting the use of rescue or breakthrough medication assists in determining the effectiveness of the current treatment regimen.
the McGill Pain Questionnaire (MPQ) may be used to reveal specific sensory attributes of pain. The MPQ has been validated as demonstrating that different pain syndromes can be consistently described with specific constellations of descriptors.
Interference or disability scales from the Multidimensional Pain Inventory (MPI) and Brief Pain Inventory (BPI) provide reliable and valid measures of the effect of chronic pain on physical and social function.27-29 These inventories provide generic measures available for all chronic pain conditions and are not disease specific like some scales.
Depression, anger, anxiety, and irritability all are accompaniments of chronic pain.12,30,31 The Beck Depression Inventory (BDI) and Profile of Mood States are widely used, reliable, and valid assessments.
People with chronic pain report that most aspects of their daily lives are affected by chronic pain. Enjoyment of life in general, emotional well being, fatigue, weakness, and sleep are difficult to assess if separate questionnaires are required
An aggregate of all aspects of the patient’s experience, including global improvement and satisfaction, can be measured by the Patients’ Global Impression of Change scale.
Types of Pain
There are numerous mechanisms of pain with potential overlapping presentations. Nociceptive, or inflammatory, pain results from activity in neural pathways caused by potentially tissue-damaging stimuli.37 Examples include postoperative pain, arthritis, mechanical low back pain, sickle cell crises, and injuries
Neuropathic pain is defined as pain initiated or caused by a primary lesion or dysfunction of the nervous system.38,39 Examples of peripheral neuropathic pain syndromes include HIV sensory neuropathy, postherpetic neuralgia, and diabetic neuropathy.
Examples of central neuropathic pain include central post-stroke pain, spinal cord injury pain, trigeminal neuralgia, and multiple sclerosis pain.
Patients with chronic pain may experience one or more types of pain syndromes simultaneously.
The patient with chronic pain has many comorbidities and consequences that require a comprehensive assessment. There are numerous scales and questionnaires that may assist the clinician with the physical examination and history. Developing a personalized “step approach” allows a thorough evaluation to take place. Organizing the clinical information into different perspectives directs attention to specific causes of the patient’s disorder and dysfunction. Patient-centered case formulations using standardized approaches and metrics provide more comprehensive health care to the patient suffering with disabling and refractory chronic pain syndromes. Addressing each pertinent perspective of the patient with chronic pain leads to a more effective treatment plan and successful management.