INTRODUCTION Blinding participants to randomization is a cornerstone of science. However, participant beliefs about their allocation can influence outcomes. We examined blind integrity, the association between trial arm belief and cessation, and potential mechanisms linking treatment arm and treatment arm belief among people with major depressive disorder (MDD) who smoke receiving varenicline in a placebo-controlled trial. METHODS 175 participants were asked at the end of treatment (EOT) if they thought they received placebo, varenicline, or were not sure. We assessed the relationship between treatment arm belief and actual treatment allocation, examined the association between treatment arm belief and EOT cessation, and evaluated changes in craving, withdrawal, side effects, depression symptoms, and smoking reward as mediators through which treatment arm was believed. RESULTS Treatment arm belief was significantly associated with actual arm assignment (χ2(2)=13.0, p=0.002). Participants in the varenicline arm were >3 times as likely to believe they were taking varenicline, vs. "not sure" (RR=3.05 [1.41-6.60], p=0.005). Participants in the placebo arm were just as likely to believe they were taking placebo vs. "not sure" (χ2[2]=0.75, p=0.69). Controlling for treatment arm, belief that one received varenicline was significantly associated with an increase in cessation rate (OR=5.91 [2.06-16.92], p=0.001). Change in the rewarding experience of smoking may mediate participant ability to discern getting varenicline B=0.077 [0.002-0.192], p <0.05). CONCLUSIONS Participants receiving varenicline can discern that they received varenicline and this belief is associated with higher cessation rates. Research is needed to continue to examine how participants correctly identify their allocation to varenicline.

中文翻译：

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透视盲区：在伐尼克兰安慰剂对照试验中吸烟的当前或过去患有重度抑郁症的患者对治疗随机化和戒烟结果的信念。

简介 让参与者不知情的随机化是科学的基石。然而，参与者对其分配的信念会影响结果。我们在安慰剂对照试验中检查了接受伐尼克兰吸烟的重度抑郁症 (MDD) 患者的盲目完整性、试验组信念与戒烟之间的关联，以及连接治疗组和治疗组信念的潜在机制。方法 175 名参与者在治疗结束 (EOT) 时被询问是否认为自己接受了安慰剂、伐尼克兰或不确定。我们评估了治疗组信念与实际治疗分配之间的关系，检查了治疗组信念与 EOT 戒断之间的关联，并评估了渴望、戒断、副作用、抑郁症状和吸烟奖励的变化，作为治疗组信念的中介因素。结果 治疗组信念与实际组分配显着相关（χ2(2)=13.0，p=0.002）。伐尼克兰组的参与者相信自己正在服用伐尼克兰的可能性是“不确定”的 3 倍以上 (RR=3.05 [1.41-6.60], p=0.005)。安慰剂组的参与者相信自己正在服用安慰剂的可能性与“不确定”的可能性相同（χ2[2]=0.75，p=0.69）。对照治疗组，认为接受伐尼克兰治疗的患者与戒烟率增加显着相关（OR=5.91 [2.06-16.92]，p=0.001）。吸烟奖励体验的变化可能会调节参与者辨别服用伐尼克兰的能力 B=0.077 [0.002-0.192]，p <0.05）。结论 接受伐尼克兰治疗的参与者可以辨别出他们接受了伐尼克兰治疗，并且这种信念与较高的戒烟率相关。需要继续研究参与者如何正确识别他们对伐尼克兰的分配。