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，但目前针对其治疗过程中不良结局的相关研究仍较为匮乏。本研究针对病理性健康焦虑患者接受CBT治疗时的不良结局——包括不良事件、整体症状恶化及治疗脱落情况，基于对19项随机对照试验的系统综述（检索数据库涵盖PubMed、PsycInfo及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创研究（合并样本量N=336）开展了相关分析。在该系统综述中，CBT组10%的受试者报告至少发生1例不良事件，17%出现治疗脱落，研究间异质性显著。在本次原创研究中，17%的受试者报告至少发生1例不良事件，0~10%的受试者符合整体症状恶化的判定标准，10~19%出现治疗脱落。在指导性网络介导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治疗脱落率更高；更高的治疗依从性则与健康焦虑更显著的改善相关。病理性健康焦虑患者接受CBT治疗时常出现不良效应，但在常规临床场景下，鉴于该疗法的疗效，此类不良效应通常处于可接受的范围内。目前仍需更统一的研究方法，以加深我们对不良事件、治疗脱落及整体症状恶化的理解，并明确如何预防这些不良结局。过度担忧罹患或即将罹患严重疾病的人群通常会被推荐接受认知行为疗法（CBT），但目前针对该患者群体接受CBT治疗后的不良结局仍所知甚少。本研究分为两部分：首先，我们对现有文献开展系统检索，发现约10%的CBT治疗患者会报告至少1起自认为不受欢迎或负面的事件，约17%的患者会提前终止治疗，且不同研究间的结果差异显著。其次，我们分析了2项原创研究的结果，发现约17%的CBT治疗患者会报告至少1起自认为不受欢迎或负面的事件；若为面对面施测的CBT，经历此类事件的患者的健康焦虑平均改善幅度更小，但若是网络施测的CBT则无此关联。约0~10%的患者报告治疗后健康焦虑加重，10~19%的患者提前终止治疗；在网络施测的CBT中，受教育程度较低、在第2周评估时认为治疗可信度及预期性较低的患者脱落率更高。本研究结论为：不良效应相对常见，但通常较为轻微且可接受。