Factors influencing the quality of clinical trials on traditional Chinese medicine— Qualitative interviews with trial auditors, clinicians and academic researchers

Background: As clinical trials evaluating the efficacy of traditional Chinese medicine (TCM) therapies have increased, several empirical studies have shown that the quality of TCM trials are generally low in terms of risk of bias. This qualitative study aimed to investigate the factors influencing the quality of TCM clinical trials to provide strategic advice on trial quality improvement. Methods: One focus group with clinical trial auditors (n=4) and six indepth semi-structured interviews with clinical research organization managers (n=2), lecturers and researchers in TCM academic institutions (n=2), a chief physician in a TCM oncology department and a PhD candidate specialized in non-pharmaceutical TCM interventions were conducted. The interviews were audio-recorded, transcribed verbatim and thematically analyzed. Results: Factors that influenced the quality of TCM clinical trials merged on the following 6 themes: trial design; trialists/ participants; trial conducting; TCM specified problems; trial monitoring, and finally societal influences. The lack of expertise and time inputs of the trialists were repeatedly mentioned. Methodological difficulties experienced when conducting TCM trials included calculating sample size, analyzing the efficacy of TCM decoctions with multiple ingredients, blinding in trials investigating non-pharmaceutical TCM interventions were highlighted. Interviewees agreed that third-party monitoring can help improving trial quality and improved participant welfare and may accelerate recruiting processes and increase compliance; however more comprehensive regulations and funding requirements would be needed. Conclusions: This study identified real-life issues influencing the quality of TCM clinical trials from design to reporting. In addition to mandatory training for TCM trial designers and coordinators, more effective institutional oversight is required. Future studies should explore specific measures to address the methodological problems in TCM trials and explore how the quality of TCM trials can affect further evidence synthesis and clinical practice.