The best magazine
Chronic/persistent pain places a significant burden on patients, the health care system, and society, because it is associated with substantial personal suffering, lost productivity, and health care costs. Along with its significant socioeconomic impact, chronic/persistent pain can also alter normal sleep patterns in patients, which in turn may affect multiple aspects of daily life, such as interference with social relationships, diminished cognitive functions, interference with daily activities, and increased levels of anxiety and depression. Therefore, a clinical understanding of the relationship between chronic pain, pain relief, and pain-related sleep disturbances is essential for creating an effective pain management regimen. As an example, if sleep assessments are performed consistently over time (i.e., before the initiation of analgesic therapy and during treatment), changes in sleep patterns may signal the need for a change in treatment. An optimal treatment for the management of chronic/persistent pain should provide continuous around-the-clock pain control and subsequently improve sleep, thereby improving health-related quality of life in many patients. This article focuses on the disruptions in sleep that are commonly seen in patients with chronic/persistent pain, and their utility as a measure of effective pain management in clinical studies evaluating pharmacologic approaches to chronic pain management.
Chronic pain has been estimated to affect approximately 57% of the U.S. population (Peter D. Hart Research Associates, 2003). It places a significant burden on patients, resulting in decreased overall quality of life (Elliott, Renier, & Palcher, 2003), decreased sleep, interference with social relationships, diminished cognitive functions, interference with daily activities, and increased levels of anxiety and depression (Otis et al 2003, Romano and Turner 1985). In addition, chronic pain has a significant socioeconomic impact; for example, osteoarthritis, a common chronic pain condition, has been reported to be responsible for an estimated $7.11 billion per year in lost work productivity, with 65.7% of these costs attributed to chronic pain (Ricci et al., 2005).
Sleep disruptions and nonrestorative sleep are common complaints among people suffering from chronic pain, particularly among patients with conditions such as fibromyalgia, low back pain, rheumatoid arthritis, and osteoarthritis (Drewes 1999, Drewes and Arendt-Nielsen 2001, Leigh et al 1987, Leigh et al 1988; Wilcox et al., 2000). Approximately 65% of patients with chronic pain report some type of sleep problem (Deardorff, 2005), with the most common issues including delayed onset of sleep, frequent awakenings during the night, decreased duration of sleep, daytime fatigue, and sleep that is nonrestorative (Cohen et al., 2000).
For example, the National Survey of Self-Care and Aging (n = 937) found that 32.8% of Medicare beneficiaries who were aged ≥65 years reported arthritis-related sleep disruptions (Jordan, et al., 2000). In another study involving men and women >65 years of age who had chronic knee pain due to osteoarthritis (n = 429), 31% of patients reported having difficulty falling asleep; 81% reported problems maintaining sleep, and 51% reported problems with early morning awakenings (Wilcox, et al., 2000). Specific sleep problems experienced by patients with chronic pain have also been identified, such as altered sleep architecture (with more time spent in stage 1 sleep, i.e., drowsiness) and more frequent night-time awakenings and body movements (Drewes 1999, Drewes and Arendt-Nielsen 2001). A similar study reported significant increases in stage 1 sleep and significant decreases in stage 2 sleep (intermediate stage of sleep) in patients with osteoarthritis compared with healthy controls (Leigh, et al., 1988), providing further evidence of the widespread nature of sleep disturbances in patients with osteoarthritis. Interestingly, the investigators in the latter study noted that the degree of sleep disturbance was limited by continued treatment with concurrent antiinflammatory and analgesic medications, suggesting that sleep may be an appropriate marker for treatment efficacy in these patients. The present article reviews the disruptions in sleep that are commonly seen in patients with chronic pain and their utility as a measure of effective pain management in clinical studies evaluating pharmacologic approaches to chronic pain management.
Source: ...