Pain
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Randomized Controlled Trial Multicenter Study Clinical Trial
Gabapentin in postherpetic neuralgia: a randomised, double blind, placebo controlled study.
A multicentre double blind, randomised, placebo controlled 7-week study evaluated the efficacy and safety of gabapentin 1800 or 2400 mg/day in treating postherpetic neuralgia. Three hundred and thirty-four men and women aged at least 18 years (mean 73) received gabapentin 1800 or 2400 mg daily or placebo in three divided doses with a forced titration schedule. The primary outcome measure was change in average daily pain diary score (baseline week v final week). ⋯ Overall gabapentin was well tolerated. The most common adverse events were dizziness and somnolence, particularly during the titration phase. Thus, this study confirms the role of gabapentin as an efficacious and well-tolerated treatment for postherpetic neuralgia.
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Multicenter Study Clinical Trial Controlled Clinical Trial
Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale.
Pain intensity is frequently measured on an 11-point pain intensity numerical rating scale (PI-NRS), where 0=no pain and 10=worst possible pain. However, it is difficult to interpret the clinical importance of changes from baseline on this scale (such as a 1- or 2-point change). To date, there are no data driven estimates for clinically important differences in pain intensity scales used for chronic pain studies. ⋯ The relationship between percent change and the PGIC was also consistent regardless of baseline pain, while higher baseline scores required larger raw changes to represent a clinically important difference. The application of these results to future studies may provide a standard definition of clinically important improvement in clinical trials of chronic pain therapies. Use of a standard outcome across chronic pain studies would greatly enhance the comparability, validity, and clinical applicability of these studies.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Prediction of physician visits and prescription medicine use for back pain.
The primary purpose of this study was to examine the extent to which specific patient attitudes and beliefs about medical care and self-care for back pain predict future healthcare use. An automated database allowed examination of the predictive relationships in two primary care patient samples. In general, beliefs that physicians should find a definitive cause and permanent cure for back pain predicted neither physician visits nor prescription medication fills. ⋯ Factor analyses of the item set yielded three factors, but inconclusive results; the internal consistency of the identified sub-scales was only moderate. However, findings that a subset of items predicted physician visits and prescriptions medication fills, and was sensitive to change following a self-care intervention, suggest avenues for improving measurement of self-care orientation. These findings help clarify specific patient attitudes and beliefs that are related to healthcare utilization and suggest that a subset of these beliefs can be modified through a brief educational intervention.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Comparative reliability and validity of chronic pain intensity measures.
Reliable and valid measures of pain are essential for conducting research on chronic pain. The purpose of this longitudinal study was to compare the reliability and validity of several measures of pain intensity. One hundred twenty-three patients with chronic pain were administered telephone interview versions of 0-10 scales of current, worst, least and average pain, immediately prior to beginning a multidisciplinary treatment program. ⋯ Contrary to prediction, the composite measures did not show a statistically significant superiority to the individual ratings in terms of their ability to detect change in pain intensity from pre-treatment to various points after treatment. The composite scores did, however, show greater stability than did the individual ratings after treatment. The practical conclusions of this study are; (1), individual 0-10 pain intensity ratings have sufficient psychometric strengths to be used in chronic pain research, especially research that involves group comparison designs with relatively large sample sizes, but, (2), composites of 0-10 ratings may be more useful when maximal reliability is necessary, (e.g. in studies with relatively small sample sizes, or in clinical settings where monitoring of changes in pain intensity in individuals is needed).
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Randomized Controlled Trial Multicenter Study Clinical Trial
N of 1 randomised controlled trials of oral ketamine in patients with chronic pain.
Anecdotal reports suggest that the general anaesthetic drug ketamine, taken orally in low doses, can give rise to some extra analgesia in patients with refractory neuropathic pain. This study was designed to determine the proportion of patients with chronic neuropathic pain responding to oral ketamine, and then to separate the true treatment effect from non-specific effects by means of an n of 1 randomised controlled trial. Twenty-one patients gave informed consent and completed daily pain diaries and continued on their usual treatments (drug and non-drug) for the duration of the study. ⋯ We conclude that oral ketamine only gave rise to an extra analgesic response in three out of 21 patients with chronic neuropathic pain (14%). Adverse effects limited the use of the drug in almost half of the patients. The n of 1 trial was useful in demonstrating no true therapeutic effect for the ketamine in two thirds of the patients progressing to that part of the trial.