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From: Chronic Pain: A Primary Care Guide to Practical Management Edited by: D. A. Marcus © Humana Press, Totowa, NJ
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Chronic Pain and Headache
1. CHRONIC PAIN: EPIDEMIOLOGY
Pain is a common chief complaint for patients in primary care, with approxi- mately 10 to 20% reporting chronic pain (1–3) (see Fig. 1). In a sample of general practices, chronic pain requiring pain medications and treatment was identified in 14% of patients, with 6% of these patients reporting high levels of disability because of pain (4). A World Health Organization survey of patients in primary care in 14 countries revealed that back, head, and joint pain are the three most commonly affected areas (3) (Fig. 2). Interestingly, two-thirds of patients reported pain affecting more than one body region.
Pain is even more prevalent in samples of patients in community settings.
Musculoskeletal complaints were reported by 80% of 15- to 84-year-olds in a general population survey, with 13% reporting substantial pain (5). The area most commonly affected by musculoskeletal pain is the back (6) (Fig. 3). In addition, musculoskeletal conditions (which frequently involve chronic pain) rank as fifth in terms of hospital costs and first in terms of costs related to work absenteeism and disability (7). A survey of health care expenditures for em- ployees showed that among all physical health complaints, mechanical low back pain was the fourth most expensive condition, with other back disorders collectively ranked as the seventh most expensive condition (8).
Patients reporting chronic pain often experience psychological distress and disability in addition to pain (Fig. 4). The significant impact of chronic pain was recently highlighted in a study by Blyth and colleagues (9). Their survey of Australian adults with chronic pain revealed that, although only 29% reported work restrictions owing to pain complaints, 58% reported reduced work effec- tiveness. Respondents reported working with pain for 84 days during a 6- month period, but only losing 4.5 days from work because of pain.
Considering both work absenteeism plus reduced-effectiveness workdays, an average of 16 workday equivalents was lost over 6 months.
Despite frequent patient complaints about chronic pain, a recent survey of primary care physicians noted that only 15% felt comfortable treating patients with chronic pain (10). Primary care physicians were also uncomfortable with
Fig. 1. Prevalence of a chief complaint of any pain and chronic pain in primary care (Based on refs. 1–3.)
Fig. 2. Pain location reported in international survey of primary care patients.
(Based on ref. 3.)
Fig. 3. Musculoskeletal pain prevalence. Percentage of patients from primary care physician practices reporting musculoskeletal pain lasting more than 1 week during the previous month. (Based on ref. 6.)
the expanded need to prescribe opioids to patients with chronic pain; 41% of doctors waited for patients to initiate a request for pain medication.
2. CHRONIC PAIN ASSESSMENT TOOLS
The evaluation of pain begins with identifying pain location. This is most conveniently done by asking patients to complete a simple pain drawing (Fig. 5).
This drawing effectively identifies all potentially important pain areas, rather than focusing only on a particular area of immediate concern to the patient.
Fig. 4. Chronic pain-associated distress and disability. Based on data derived from the World Health Organization survey of primary care patients in 14 countries. (Based on ref. 3.)
Fig. 5. Pain drawing. Instructions to pain drawing: please shade all painful areas, using the following key: ///// = pain; ::::: = numbness; *** = burning or hypersensitiv- ity to touch.
Although the majority of patients will report more than one active pain area (3), many patients may only express verbal complaints about the area that is most troublesome on the day of evaluation or for which the patient believes treatment is available. For example, patients with fibromyalgia may bring a chief com- Fig. 6. Chief complaints with sample pain drawings. (A) episodic, left-sided, inca- pacitating headache; (B) episodic, left-sided, incapacitating headache; (continued)
Fig. 6. (continued) (C) persistent low back pain; (D) persistent low back pain. Diag- noses: (A) migraine, (B) migraine plus fibromyalgia, (C) myofascial low back pain, and (D) low back pain with radiculopathy.
plaint of headache or low back pain to the doctor, despite having widespread pain areas. Failure to recognize additional pain complaints may result in an incomplete diagnosis and failure to adequately identify all of the patient’s dis- abling complaints. Samples of completed pain drawings are shown in Fig. 6.
location by 38%, throbbing quality by 29%, photophobia by 11%, or phonopho- bia by 11%.
Patients should also be asked to rate the severity of their pain. Verbal rating scales (using selected descriptive adjectives), visual analog scales (marking a severity score on a line scaled from 0 to 100), and numerical rating scales (e.g., 0 = no pain and 10 = excruciating pain) may all be used. Numerical rating scales (“select a pain severity rating between 0 and 10”) are easy for patients, valid, and sensitive to treatment impact (13). Furthermore, recorded numeri- cal pain scores can be easy to use to assess and document the effectiveness of treatment interventions.
3. SUMMARY
Clinicians can gain confidence and comfort with managing chronic pain by becoming more knowledgeable about the causes, diagnoses, and treat- ment options for patients with chronic pain. This can be achieved with easy-to- use pain assessment strategies and tools. This book is designed to provide practical information about the pathogenesis, diagnosis, and treatment of the most common chronic pain conditions seen in typical patients, as presented in case histories. In addition, patient assessment and educational materials are provided in formats that are easy to use in most busy primary care practices.
The practical information provided in this text should improve both the under- standing of these conditions and the efficacy of chronic pain management options in primary care. The information and tools provided in this book should help the busy clinician simplify broad patient complaints into manageable prob- lems, with tools for addressing commonly encountered problems.
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