Unwanted outcomes in cognitive behavior therapy for pathological health anxiety: a systematic review and a secondary original study of two randomized controlled trials

Cognitive behavior therapy (CBT) is effective for pathological health anxiety, but little is known about unwanted outcomes. We investigated unwanted outcomes in the form of adverse events, overall symptom deterioration, and dropouts in CBT for pathological health anxiety based on a systematic review of 19 randomized controlled trials (PubMed, PsycInfo, and OATD; last updated 2 June 2023; pooled N = 2188), and then a secondary original study of two randomized controlled trials (pooled N = 336). In the systematic review, 10% of participants in CBT reported at least one adverse event and 17% dropped out. Heterogeneity was substantial. In the original investigation, 17% reported at least one adverse event, 0–10% met criteria for overall symptom deterioration, and 10–19% dropped out. In guided Internet-delivered CBT, dropouts were more common with lower education and lower credibility/expectancy ratings. Higher adherence was associated with a larger reduction in health anxiety. Unwanted effects are routinely seen in CBT for pathological health anxiety, but, under typical circumstances, appear to be acceptable in light of the treatment’s efficacy. There is a need for more consistent methods to improve our understanding adverse events, dropouts, and overall symptom deterioration, and how these outcomes can be prevented. People who worry excessively about having or developing a serious disease are commonly offered cognitive behavior therapy (CBT). Little is known about unwanted outcomes in CBT for this patient group. This study had two parts. First, we conducted a systematic search of the existing literature where we found that about 10% of patients in CBT experience an event that they perceive as unwanted or negative. About 17% of patients drop out of treatment prematurely. Results differed substantially between studies. Second, we analyzed the outcome of two original studies and found that about 17% of patients in CBT experience an event that they perceive as unwanted or negative. Patients who experienced such an event reported, on average, a smaller reduction in health anxiety if CBT was delivered face-to-face, but not if it was delivered via the Internet. About 0–10% rated their health anxiety as having become worse after CBT, and 10–19% dropped out prematurely. In CBT delivered via the Internet, patients were more likely to drop out if their level of education was lower, and if they rated the treatment as less credible and expectancy-evoking during week 2. We conclude that unwanted effects are relatively common but typically mild and acceptable.

认知行为疗法（Cognitive Behavior Therapy, CBT）对病理性健康焦虑具有确切疗效，但目前学界对其潜在不良结局的研究仍较为匮乏。本研究基于对19项随机对照试验（randomized controlled trial, RCT）的系统综述（检索数据库涵盖PubMed、PsycInfo与OATD；最后更新于2023年6月2日；合并样本量N=2188），以及针对2项随机对照试验的二次原始研究（合并样本量N=336），探讨了CBT用于病理性健康焦虑时的不良结局，具体包括不良事件、整体症状恶化与治疗脱落情况。
在系统综述阶段，接受CBT的受试者中有10%报告至少出现1起不良事件，17%提前终止治疗，研究间异质性显著。而在二次原始研究中，17%的受试者报告至少出现1起不良事件，0%~10%符合整体症状恶化的判定标准，10%~19%提前脱落。在指导性互联网式CBT中，受教育程度较低、治疗可信度与预期评分较低的受试者脱落率更高；治疗依从性越高，健康焦虑的缓解幅度越大。
研究显示，病理性健康焦虑患者接受CBT时常可观察到不良效应，但在常规临床场景下，结合该疗法的临床疗效来看，此类不良效应通常处于可接受范围。目前仍需采用更统一的研究方法，以深化我们对不良事件、治疗脱落与整体症状恶化的认知，并明确此类结局的预防策略。
针对过度担忧罹患或进展为严重疾病的人群，临床通常会推荐认知行为疗法（CBT），但针对该群体接受CBT后的不良结局，目前相关研究仍较为稀缺。本研究分为两个部分：其一，我们对现有文献开展系统检索，结果显示约10%的CBT受试者会经历自认为不受欢迎或负面的事件，约17%的患者提前终止治疗，且不同研究间的结果差异显著。其二，我们分析了2项原始研究的数据，发现约17%的CBT受试者会经历自认为不受欢迎或负面的事件。若为面对面式CBT，经历此类事件的受试者的健康焦虑平均缓解幅度更小；但若是互联网式CBT，则未观察到该关联。约0%~10%的受试者报告治疗后健康焦虑加重，10%~19%提前脱落。在互联网式CBT中，受教育程度较低、在第2周时对治疗的可信度与预期效果评分较低的受试者，脱落概率更高。
综上，CBT用于病理性健康焦虑时的不良效应相对常见，但通常程度较轻且可被接受。