Pain
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A computer and a hand search of the literature recovered 33 papers from which 25 trials suitable for meta-analysis were identified. We compared the effectiveness of cognitive-behavioural treatments with the waiting list control and alternative treatment control conditions. There was a great diversity of measurements which we grouped into domains representing major facets of pain. ⋯ Differences on the following domains were not significant; mood/affect (depression and other, non-depression, measures), cognitive coping and appraisal (negative, e.g. catastrophization), and social role functioning. We conclude that active psychological treatments based on the principle of cognitive behavioural therapy are effective. We discuss the results with reference to the complexity and quality of the trials.
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Fillingim and Maixner (Fillingim, R. B. and Maixner, W., Pain Forum, 4(4) (1995) 209-221) recently reviewed the body of literature examining possible sex differences in responses to experimentally induced noxious stimulation. Using a 'box score' methodology, they concluded the literature supports sex differences in response to noxious stimuli, with females displaying greater sensitivity. ⋯ Given the estimated effect size of 0.55 threshold or 0.57 for tolerance, 41 subjects per group are necessary to provide adequate power (0.70) to test for this difference. Of the 34 studies reviewed by Fillingim and Maixner, only seven were conducted with groups of this magnitude. The results of this study compels to caution authors to obtain adequate sample sizes and hope that this meta-analytic review can aid in the determination of sample size for future studies.
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The analgesic effectiveness and safety of oral tramadol were compared with standard analgesics using a meta-analysis of individual patient data from randomised controlled trials in patients with moderate or severe pain after surgery or dental extraction. Calculation of %maxTOTPAR from individual patient data, and the use of > 50%maxTOTPAR defined clinically acceptable pain relief. Number-needed-to-treat (NNT) for one patient to have > 50%maxTOTPAR compared with placebo was used to examine the effectiveness of different single oral doses of tramadol and comparator drugs. ⋯ There was a dose response with tramadol, tending towards higher incidences at higher doses. Single-patient meta-analysis using more than half pain relief provides a sensitive description of the analgesic properties of a drug, and NNT calculations allow comparisons to be made with standard analgesics. Absolute ranking of analgesic performance should be done separately for postsurgical and dental pain.
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The aim of this study was to examine whether mean data from categorical pain intensity and visual analogue scales for both pain intensity and relief could be used reliably to derive dichotomous outcome measures for meta-analysis. Individual patient data from randomised controlled trials of single-dose analgesics in acute postoperative pain were used. The methods used were as follows: data from 132 treatments with over 4700 patients were used to calculate mean %maxSPID (categorical pain intensity), %maxVAS-SPID (visual analogue pain intensity) and %maxVAS-TOTPAR (visual analogue pain relief); these were used to derive relationships with the number of patients who achieved at least 50% pain relief (%maxTOTPAR). ⋯ Reports of randomised trials of analgesics frequently describe results of studies in the form of mean derived indices, rather than using discontinuous events, such as number of proportion of patients obtaining at least 50% pain relief. Because mean data inadequately describe information with a non-normal distribution, combining such mean data in systematic reviews may compromise the results. Showing that dichotomous data can reliably be derived from mean SPID, VAS-SPID and VAS-TOTPAR as well as TOTPAR data in previously published acute pain studies makes much more information accessible for meta-analysis.
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The objective of this study was to review the effectiveness and safety of antidepressants in neuropathic pain. In a systematic review of randomised controlled trials, the main outcomes were global judgements, pain relief or fall in pain intensity which approximated to more than 50% pain relief, and information about minor and major adverse effects. Dichotomous data for effectiveness and adverse effects were analysed using odds ratio and number needed-to-treat (NNT) methods. ⋯ Compared with placebo, of 100 patients with neuropathic pain who are given antidepressants, 30 will obtain more than 50% pain relief, 30 will have minor adverse reactions and four will have to stop treatment because of major adverse effects. With very similar results for anticonvulsants it is still unclear which drug class should be first choice. Treatment would be improved if we could harness the dramatic improvement seen on placebo in some of the trials.