The journal of pain : official journal of the American Pain Society
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The current study compared the psychometric properties of 2 commonly used measures of pain-related interference, the Graded Chronic Pain (GCP) Disability scale and 3 modified versions of the Brief Pain Inventory (BPI) Interference scale. Participants were 127 persons with spinal cord injury (SCI) who reported pain on a survey. The results suggest that the GCP Disability scale and 3 versions of the BPI Interference scale are reliable and valid measures of pain-related interference in persons with SCI and pain. All 4 measures evidenced excellent internal consistency. The composite scores and individual items of the GCP Disability scale and each version of the BPI Interference scale were significantly related to average pain intensity during the past week and a global measure of psychological functioning. Finally, as pain intensity ratings increased (from mild to moderate to severe), so did the composite and item-level ratings of interference for each version of the BPI Interference scale and GCP Disability scale. Strengths and weaknesses of each measure for use with persons with disability and pain are discussed. ⋯ The GCP Disability scale and 3 versions of the BPI Interference scale (modified for use in persons with disabilities) appear to be reliable and valid measures of pain-related interference in persons with SCI. Future research should examine their psychometric properties in other disability populations.
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Pain intensity is commonly measured by patient ratings on numerical rating scales (NRS). However, grouping such ratings into categories may be useful for guiding treatment decisions or interpreting clinical trial outcomes. The purpose of this study was to examine pain intensity classification in 2 samples of persons with spinal cord injuries (SCI) and chronic pain. The first sample (n = 307) rated the average intensity and activity interference of pain in general, and the second sample (n = 174) rated their worst pain problem. Pain intensity was categorized as mild, moderate, or severe using 4 possible classification systems; analyses were performed to determine the classification system that best distinguished the pain intensity groups in terms of activity interference. In both samples, the optimal mild/moderate boundary was lower (mild = 1-3 on a 0-10 NRS scale) than that reported previously for individuals with other pain problems. The possibility that pain may interfere with activity at lower levels for individuals with SCI requires further exploration. The moderate/severe boundary suggested by previous research was confirmed in only one of the samples. Implications for the assessment of pain intensity and functioning in persons with SCI and pain are discussed. ⋯ Although pain in individuals with SCI is common, more research is needed regarding its characteristics and treatment. This study sought to develop an empirically based classification system for mild, moderate, and severe pain that could be useful for applying clinical treatment guidelines and for interpreting the results of much-needed clinical trials.
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Self-report ratings of pain intensity are ubiquitous in research and clinical practice. In addition to rating their current pain, patients are often asked to provide ratings to represent pain intensity over several days or weeks. Few data are available that provide insight into how people understand and accomplish this recall task. This study describes the results of structured interviews with 106 rheumatology patients with chronic pain about how they arrived at their ratings of pain intensity on a visual analog scale referenced to the past week. Most patients were unable to coherently articulate how they derived their ratings. Moreover, there was no consistency across patients. A variety of different strategies were identified that guided their responses. These results support the concern about the meaning and validity of retrospective recall ratings. Recall of pain, a seemingly simple task, is a deceptively more complex phenomenon. Efforts to improve the measurement of recalled pain need to be explored. Improving instructional sets, clearer specification of the dimensions of pain being targeted, avoiding use of a single item to measure pain, improved description of intended reference groups, and determining the length of time that patients are able to remember pain and limiting recall periods are reasonable methods that need to be explored. ⋯ These results emphasize our lack of a full understanding of the meaning of the information elicited by commonly used pain recall questions. They point to the potential importance of clearly specifying what qualities of pain are sought and how the patient should summarize them over the reporting period.
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The effectiveness of amitriptyline, carbamazepine, gabapentin, and tramadol for the treatment of neuropathic pain has been demonstrated, but it is unknown which one is the most cost-effective. We designed a cost-utility analysis of a hypothetical cohort with neuropathic pain of postherpetic or diabetic origin. The perspective of the economic evaluation was that of a third-party payor. For effectiveness and safety estimates, we performed a systematic review of the literature. For direct cost estimates, we used average wholesale prices, and the American Medicare and Clinical Laboratory Fee Schedules. For utilities of health states, we used the Health Utilities Index. We modeled 1 month of therapy. For comparisons among treatments, we estimated incremental cost per utility gained. To allow for uncertainty from variations in drug effectiveness, safety, and amount of medication needed, we conducted a probabilistic Monte Carlo simulation. Amitriptyline was the cheapest strategy, followed by carbamazepine, and both were equally beneficial. Gabapentin was the most expensive as well as the least beneficial. A multivariable probabilistic simulation produced similar results to the base-case scenario. In summary, amitriptyline and carbamazepine are more cost-effective than tramadol and gabapentin and should be considered as first-line treatment for neuropathic pain in patients free of renal or cardiovascular disease. ⋯ Prescription practices should be based on the best available evidence, which includes the evaluation of the medication's cost-effectiveness. This does not mean that the cheapest or the most expensive, but rather the most cost-effective medication should be chosen-the one whose benefits are worth the harms and costs. We report a cost-effectiveness evaluation of treatments for neuropathic pain.
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This study investigated the extent to which psychosocial factors (partner responses to pain behaviors, social support) are associated with pain-related activity interference and depressive symptom severity among individuals with spinal cord injury (SCI) and chronic pain. Seventy adults (45 men, 25 women) with SCI and pain and 68 partners completed Part II of the West Haven-Yale Multidimensional Pain Inventory, a measure of partner responses to pain behaviors. Individuals with SCI and pain also completed the Social Support Questionnaire-6, a modified Brief Pain Inventory Pain Interference Scale, and the Center for Epidemiological Studies-Depression scale. SCI subject ratings of partner responses to pain behaviors, but not partner ratings, were associated significantly with pain-related activity interference and depressive symptom severity. Negative partner response to pain behaviors explained the most variance in these 2 outcome measures. The results provide preliminary support for the importance of partner responses to pain behaviors in outcomes of individuals with chronic pain and SCI. ⋯ Chronic pain is a significant problem for many persons with spinal cord injury. In this sample of individuals with spinal cord injury and pain, perceived partner negative responses to pain behaviors were associated positively with activity interference and depression. Decreasing negative partner responses to pain behaviors might be a potentially important clinical intervention in this population.