Guide to Chronic Pain Assessment Tools
Many busy clinicians struggle with finding the time to conduct a thorough assessment of the pain patient, especially the patient with chronic pain. This is the case even though pain is among the most common reasons patients seek medical care.
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.1
See article "Formulation: The Four Perspectives Of a Patient in Chronic Pain" for description of formulations.
Treating the Whole Patient
Chronic pain assessments are often more involved and complex than assessment of the patient with acute pain. It is now widely recognized that there is more to the management of pain than just analgesia. The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) has recommended a set of core outcome domains for clinical trials in pain. These domains include pain, physical functioning, emotional functioning, participant ratings of global improvement, symptoms and adverse events, and participant disposition.2 Although these domains are recommended for clinical trial outcome measures, they show the importance of viewing the patient comprehensively.
In chronic noncancer pain, pain is defined as lasting for 3 months or longer. It may be experienced by the patient as continuous or as intermittent and recurrent.3 Because chronic pain affects multiple areas of a patient’s life, the diagnosis and treatment should incorporate a multidisciplinary approach. To address the affective, cognitive, and behavioral aspects of pain management, a psychiatrist may be consulted. The psychiatrist should be involved early in the course of treatment, and comprehensive interdisciplinary care is recommended.4
The role of the psychiatrist should be to individualize the case formulation, diagnose co-occurring psychiatric disorders, and apply psychopharmacology to the treatment of chronic pain syndromes.5 The initial assessment is vitally important and will guide the proper diagnosis, treatment plan, and role of other clinicians and programs, as well as provide the patient’s baseline at the start of treatment.
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 (Table 1).
A comprehensive history and physical and neurologic examination should be performed when evaluating and identifying the patient’s subjective description of pain.6 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 (Table 2).7During the full assessment, consultants may perform further evaluations and diagnostic tests. Specialized assessments, such as imaging, neurophysiologic, laboratory, and psychological tests, must be determined on a case-by-case basis.8
A 10-step approach to long-term chronic pain management is useful (Table 3).9 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. The use of pain scales may be of benefit and is discussed in a separate section. A useful mnemonic to perform a comprehensive evaluation is L-DOC-SARA—location, duration, onset, characteristics, severity and pain goal, aggravating factors, relieving factors, and associate symptoms. Another mnemonic to assess treatment response is the four As (analgesia, adverse events, activities of daily living [ADLs], and aberrant behaviors). The four As should be followed and monitored throughout treatment.
Keep in mind during the assessment that multiple aspects of the patient’s well being are affected by a chronic pain disorder. 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.11,12 It is useful to keep the IMMPACT domains recommended for clinical trials in mind (eg, pain intensity, physical functioning, emotional functioning, participant ratings of global improvement, symptoms, and adverse events). Not every patient requires multiple scales as recommended by IMMPACT, but they should be kept in mind when performing an evaluation, generating the case formulation, and following the patient’s care (Table 4). For example, compare a patient’s ADLs on a typical day from visit to visit via an outline. Evaluate mood changes and anxiety symptoms along with possible comorbid depression or anxiety disorders. Always assess for suicide, because this population has a suicide rate two to three times the rate of that in the general population.13 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.