Blended cognitive-behavioural therapy (bCBT) combines face-to-face CBT (FtFCBT) and Internet-based CBT (iCBT) into one integrated treatment protocol, opening up new ways to deliver therapy, increase cost-effectiveness and resolve scarcity of therapist availability. When traditional therapy is transformed into a new format, there is a need to evaluate whether principles of the new protocol are consistently applied.

This study aimed to explore therapist fidelity to bCBT protocols for anxiety disorders in specialised mental health care and to assess whether fidelity is related to patient characteristics. Adult patients (N = 44) received bCBT within a randomised controlled trial. Ratio of FtF to online sessions, session frequency and therapist adherence to instructions were assessed.

Overall therapist fidelity with regard to ratio of blending, session frequency and instructions was high. Correlations were found between patients' share of online sessions and both session frequency (r = 0.373, p = .013), as well as patient computer experience (r = 0.314, p = .038). Adherence to instructions in FtF sessions was based on a subset of patients (n = 23) and should therefore be interpreted with caution.

The blended approach was generally delivered as intended, indicating that the format is feasible in specialised mental health.

混合认知行为疗法 (bCBT) 将面对面 CBT (FtFCBT) 和基于互联网的 CBT (iCBT) 结合成一种综合治疗方案，开辟了提供治疗的新方法，提高了成本效益并解决了治疗师短缺的问题。当传统疗法转变为新形式时，需要评估新方案的原则是否得到一致应用。

本研究旨在探讨专业心理保健中治疗师对焦虑症 bCBT 方案的忠诚度，并评估忠诚度是否与患者特征相关。成年患者 ( N = 44) 在一项随机对照试验中接受了 bCBT。评估了 FtF 与在线治疗的比率、治疗频率以及治疗师对指示的遵守情况。

治疗师在混合比例、治疗频率和指导方面的整体忠诚度很高。我们发现患者的在线会话份额与会话频率 ( r = 0.373， p = .013) 以及患者的计算机体验 ( r = 0.314， p = .038) 之间存在相关性。 FtF 会议中对指示的遵守基于一部分患者 ( n = 23)，因此应谨慎解释。

混合方法通常按预期交付，表明该格式在专业心理健康领域是可行的。