Impact of experimentally-induced expectancy on the analgesic efficacy of tramadol in chronic pain patients: A 2 x 2 factorial, randomized, placebo-controlled, double-blind trial
Impact of experimentally-induced expectancy on the analgesic efficacy of tramadol in chronic pain patients: A 2 x 2 factorial, randomized, placebo-controlled, double-blind trial
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DOI：
10.1016/s0885-3924(01)00265-2
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发表时间：
2001-03-01
影响因子：
4.7
通讯作者：
Kleijnen, J
中科院分区：
文献类型：
--
作者：
de Craen, AJM;Lampe-Schoenmaeckers, AJEM;Kleijnen, J
药物试验之间的治疗效果差异通常归因于不同的患者特征，结果评估的差异和随机误差。我们先前假设，药物试验之间治疗效果的部分差异可能是由非特异性因素的差异引起的。在一项随机临床试验中，我们的目的是研究实验诱导的预期是否可以改变曲马多相对于安慰剂在慢性疼痛患者中的镇痛作用。在一项2 × 2析因、随机、安慰剂对照、双盲试验中，慢性疼痛门诊就诊的慢性疼痛患者被随机分配接受单次口服剂量50 mg曲马多或安慰剂，并进一步随机接受由医生口头表达的关于药物预期镇痛效果的阳性或中性信息：在基线时以及0.5、1、2、4、6和8小时后使用10厘米视觉模拟量表测量疼痛强度。基线。1小时疼痛强度差异，计算为基线与0.5和1小时之间疼痛强度差异的总和，作为主要结局指标。28例患者在积极预期后接受治疗并随机分配至曲马多组，其1小时疼痛强度差异之和为1.4 cm，而27例随机分配至安慰剂组的患者，其1小时疼痛强度差异之和为0.8 cm。这对应于曲马多相对于安慰剂的镇痛作用为0.6 cm（95%置信区间[CI]，-0.5 cm至1.8 cm）。随机分配至曲马多组的中性预期组的28名患者报告疼痛强度差异之和减少1.4 cm，而安慰剂组的28名患者报告减少0.9 cm。这对应于曲马多相对于安慰剂的镇痛作用为0.5 cm（95% CI，-0.9 cm至1.8 cm）。阳性预期组与中性预期组的镇痛效果差异为0.1 cm（0.6 cm - 0.5 cm），无统计学意义（95% CI，-0.7 nn至1.0 cm）。该试验没有发现曲马多的镇痛效果在阳性和中性预期组之间有显著差异。这意味着这种现象要么不存在，要么我们有一个不适当的模型来证明它。无论如何，这项研究表明了应该进行的质量试验的类型，以找出哪些非特异性因素，如关于预期效果的信息，可以改变治疗效果。疼痛症状管理杂志2001; 21：210-217. (C)美国癌症疼痛缓解委员会，2001年。
Variations in treatment effects between drug trials are usually attributed to different patient characteristics, variations in outcome assessment, and random error. We have previously hypothesized that part of the variation in treatment effects between drug trials might be caused by differences in nonspecific factors. In a randomized clinical trial, we aimed to investigate whether experimentally induced expectancy can modify the analgesic effect of tramadol relative to placebo in chronic pain patients. In a 2 x 2 factorial, randomized, placebo-controlled, double-blind trial, chronic pain patients attending a chronic pain outpatient clinic were randomized to receive a single oral dose of 50 mg tramadol or placebo, and they were further randomized to receive positive or neutral information, verbally expressed by the physician, regarding the expected analgesic effect of the drug: Pain intensity was measured using a 10 centimeter visual analogue scale at baseline, and 0.5, 1, 2, 4 6, and 8 hours after. baseline. The one-hour pain intensity difference, calculated as the sum of pain intensity differences between baseline and 0.5 and 1 hour was taken as main outcome measure. The one-hour sum of pain intensity differences of 28 patients treated after positive expectation and randomized to tramadol was 1.4 cm, while in 27 patients randomized to placebo, if was 0.8 cm. This corresponds with an analgesic effect of tramadol relative to placebo of 0.6 cm (95% confidence interval [CI], -0.5 cm to 1.8 cm). The 28 patients in the neutral expectancy group who were randomized to tramadol reported a 1.4 cm decrease on the sum of pain intensity differences, while 28 patients in the placebo group reported a 0.9 cm decrease. This corresponds with an analgesic effect of tramadol relative to placebo of 0.5 cm (95% CI, -0.9 cm to 1.8 cm). The 0.1 cm difference (0.6 cm - 0.5 cm) in analgesic effect between positive and neutral expectancy group, was not statistically significant (95% CI, -0.7 nn to 1.0 cm). This trial did not discern a significant difference in the analgesic effect of tramadol between a positive and neutral expectancy group. This means that the phenomenon either does not exist, or we had an inappropriate model to demonstrate it. Regardless, this study demonstrates the type of quality trial that should be done to find out which non-specific factors, such as information regarding the expected effect, can modify treatment effects. J Pain Symptom Manage 2001; 21:210-217. (C) U.S. Cancer Pain Relief Committee, 2001.