Department of Psychological Medicine, Weston Education Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.
Institute of Pharmaceutical Science, King's College London, UK.
Br J Health Psychol. 2018 May;23(2):436-454. doi: 10.1111/bjhp.12298. Epub 2018 Feb 5.
To investigate a range of possible predictors of nocebo responses to medicines.
Prospective cohort study.
In total, 203 healthy adult volunteers completed measures concerning demographics, psychological factors, medicine-related beliefs, baseline symptoms, and symptom expectations before taking a sham pill, described as 'a well-known tablet available without prescription' that was known to be associated with several side effects. Associations between these measures and subsequent attribution of symptoms to the tablet were assessed using a hurdle model consisting of a joint logistic and truncated negative binomial regression.
Men had an increased odds of attributing symptoms to the tablet OR = 1.52, and older participants had decreased odds, OR = 0.97. Medicine-related beliefs were important, with modern health worries, belief that medicines cause harm and perceived sensitivity to medicines associated with increased odds of symptom attribution, OR = 1.02, 1.10, 1.09, respectively. Trust in medicines and pharmaceutical companies decreased the odds of symptom attribution, OR = 0.91, 0.88, respectively. The number of symptoms at baseline and the expected likelihood of symptoms were associated with an increased odds of attributing symptoms to the tablet, OR = 1.07, 1.06, respectively. Anxiety, previous symptom experience, symptom expectations, and modern health worries were also important in predicting the number of symptoms participants attributed to the tablet.
It is hard to predict who is at risk of developing nocebo responses to medicines from demographic or personality characteristics. Context-specific factors such as beliefs about and trust in medicines, current symptoms and symptom expectations are more useful as predictors. More work is needed to investigate this in a patient sample. Statement of contribution What is already known on this subject? Many patients report non-specific side effects to their medication which may arise through a nocebo effect. Whether some people are particularly predisposed to experience nocebo effects remains unclear. What does this study add? Demographic and personality characteristics are poor predictors of symptom attribution to a sham medicine. Instead, context-specific factors that concern people's beliefs surrounding medicines, their current symptoms, and symptom expectations are more useful as predictors of symptom attribution.
探究引发药物反安慰剂效应的一系列可能预测因素。
前瞻性队列研究。
共有 203 名健康成年志愿者完成了人口统计学、心理因素、与药物相关的信念、基线症状以及在服用模拟药丸（一种已知有多种副作用的非处方常用片剂）之前对症状的预期等方面的测量。采用包含联合逻辑回归和截断负二项回归的混合模型，评估这些指标与随后将症状归因于模拟药丸之间的关联。
男性归因于模拟药丸的症状的几率更高，比值比（OR）为 1.52，而年龄较大的参与者的几率较低，OR 为 0.97。药物相关信念很重要，对现代健康的担忧、相信药物会造成伤害以及认为自己对药物敏感与归因于症状的几率增加有关，OR 分别为 1.02、1.10、1.09。对药物和制药公司的信任降低了归因于症状的几率，OR 分别为 0.91、0.88。基线时的症状数量和预期症状的可能性与归因于模拟药丸的症状的几率增加有关，OR 分别为 1.07、1.06。焦虑、先前的症状体验、症状预期和对现代健康的担忧对于预测参与者归因于模拟药丸的症状数量也很重要。
很难从人口统计学或个性特征预测对药物产生反安慰剂效应的风险。与药物相关的信念、信任、当前症状和症状预期等特定于情境的因素更能预测反安慰剂反应。需要进一步研究在患者样本中这一现象。
