The journal of pain : official journal of the American Pain Society
-
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.
-
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.
-
Randomized Controlled Trial
Intravenous bolus of ultra-low-dose naloxone added to morphine does not enhance analgesia in emergency department patients.
There is some evidence from in vitro, animal, and postoperative clinical studies that low doses of opioid antagonists combined with morphine increase analgesia. The theoretical model of this effect posits that ultra-low doses of opioid antagonists selectively antagonize excitatory, but not inhibitory, opioid receptor-mediated signaling. To determine whether this effect occurs in emergency department patients presenting with severe acute pain, we conducted a randomized, double-blind placebo-controlled trial to assess the relative analgesic effect of morphine administered with 3 different doses of naloxone versus morphine alone. Patients received 0.1 mg/kg morphine intravenously (IV) over 2 min plus one of 3 different doses of naloxone (0.1 ng/kg, 0.01 ng/kg, or 0.001 ng/kg) or normal saline. A 0 to 10 numerical rating scale (NRS) was used to measure pain intensity at baseline and every 30 min up to 4 hours. One hundred fifty-six patients with a median NRS of 10 (IQR: 8-10) were studied. There were no clinically or statistically significant differences in the mean pain intensity of patients in the 4 treatment groups over the 4-hour study period, nor were there differences in the administration of additional analgesics or incidence of side effects. ⋯ Ultra-low doses of naloxone in the 0.001 ng/kg to 0.1 ng/kg range do not enhance the analgesia provided by morphine alone among emergency department patients with acute, severe pain. This suggests that naloxone in these doses is not an effective adjunct to morphine for control of acute pain.
-
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.
-
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.