Turner J A, Deyo R A, Loeser J D, Von Korff M, Fordyce W E
Department of Psychiatry, University of Washington, Seattle 98195.
JAMA. 1994 May 25;271(20):1609-14.
To estimate the importance and implications of placebo effects in pain treatment and research from the existing literature, with emphasis on their magnitude and duration, the conditions influencing them, and proposed explanations.
English-language articles and books identified through MEDLINE (1980 through 1993) and PsycLIT (1967 through 1993) database searching, bibliography review, and expert consultation.
Articles were included if they pertained to the review objectives.
Placebo response rates vary greatly and are frequently much higher than the often-cited one third. Placebos have time-effect curves, and peak, cumulative, and carryover effects similar to those of active medications. As with medication, surgery can produce substantial placebo effects, and this possibility is commonly overlooked in case series reports on back surgery. Individuals are not consistent in their placebo responses, and a placebo-responder personality has not been identified. Models advanced to explain placebo effects emphasize the role of anxiety, expectations, and learning.
Placebo effects influence patient outcomes after any treatment, including surgery, that the clinician and patient believe is effective. Placebo effects plus disease natural history and regression to the mean can result in high rates of good outcomes, which may be misattributed to specific treatment effects. The true causes of improvements in pain after treatment remain unknown in the absence of independently evaluated randomized controlled trials.
根据现有文献评估安慰剂效应在疼痛治疗及研究中的重要性和影响，重点关注其程度和持续时间、影响因素及相关解释。
通过检索MEDLINE（1980年至1993年）和PsycLIT（1967年至1993年）数据库、查阅参考文献及咨询专家获取英文文章和书籍。
纳入与综述目标相关的文章。
安慰剂反应率差异很大，且常常远高于经常提及的三分之一。安慰剂具有时间效应曲线，其峰值、累积效应和延迟效应与活性药物相似。与药物一样，手术也可产生显著的安慰剂效应，而这一可能性在关于脊柱手术的病例系列报告中常被忽视。个体的安慰剂反应并不一致，尚未确定存在安慰剂反应者的人格类型。用于解释安慰剂效应的模型强调焦虑、期望和学习的作用。
安慰剂效应会影响包括手术在内的任何临床医生和患者认为有效的治疗后的患者预后。安慰剂效应加上疾病自然史和均值回归可能导致高比例的良好预后，而这可能被错误地归因于特定治疗效果。在缺乏独立评估的随机对照试验的情况下，治疗后疼痛改善的真正原因仍然未知。
