Chinese herbal medicine for insomnia: evidence, practice and opinions

Evidence-based medicine (EBM) is a contemporary practice paradigm with a focus on improving outcomes of diagnosis and treatment through effective integration of the best available evidence, practitioners’ expertise and individual patients’ preference. In this project, Chinese herbal medicine (CHM) for insomnia is used as an example to illustrate the available evidence and identify CM practitioners’ attitudes, knowledge, skills, behaviours and barriers towards evidence-based practice (EBP). Understanding and addressing these factors will contribute to the enhancement of the practice of Chinese medicine (CM) as well as to set the priorities for CM education, research and policy development. CHM is increasingly used for insomnia in China and worldwide, and has been extensively researched and used in clinical practice. Therefore, it is a suitable exemplar providing insight into EBM in the context of CM practice. Insomnia is the most common sleep-wake disorder with notable health, social and economic burden. Cognitive and behavioural therapy for insomnia (CBT-i) and pharmacotherapy are commonly used to manage symptoms. However, many sufferers seek complementary and alternative medicine (CAM) to improve their sleep and to manage daytime dysfunction. As a form of CAM, Chinese medicine has a long history of use for insomnia and continues to be frequently utilised. Emerging preclinical and clinical evidence suggests that CHM may be beneficial for improving sleep quality. Despite the frequent use of CHM for insomnia it remains largely unclear if CM doctors use EBM to inform their clinical practice. Therefore, this project uses a step-wise approach to understand, firstly, the best available evidence of CHM for insomnia and secondly, to what extent is the evidence being translated into clinical practice. The present study consists of four components: 1) a systematic review (SR) of randomised controlled trials (RCTs); 2) a systematic analysis of the historical literature; 3) a quantitative survey of CM practitioners; and 4) a qualitative interview of CM practitioners. Part One: Current Clinical Evidence of CHM for Insomnia: A Systematic Review and Meta-Analysis This SR with meta-analysis answers the following research questions: Does CHM produce beneficial effects in people with insomnia in terms of sleep quality?’ Does CHM cause any adverse events in people with insomnia and, if so, what is the nature of the adverse events?’ Seventy-nine RCTs involving 7, 886 participants were included in the SR and 76 in the meta-analyses. Findings from this review revealed that CHM improves subjective sleep quality and quantity in people with insomnia. There was no significant difference between CM and the placebo with respect to the frequency and severity of adverse events. Firm conclusions could not be drawn on the comparative effectiveness between CHM and benzodiazepine drugs or psychotherapy due to heterogeneity and risks of bias in the included RCTs. Part Two: Traditional Use of CHM for Insomnia: A Systematic Analysis of the Historical Literature This part of the research answers the following research questions: What Chinese herbal formulae and individual herbs had been referenced and indicated for the treatment of insomnia in the historical literature?’ Is there a difference between traditional and contemporary use of CHM for insomnia and, if so, what are the implications for research and practice?’ The analysis revealed that there were 729 citations involving multi-herb formulae of CHM for insomnia. These herbal formulae were used for people with insomnia based on the CM diagnostic framework. Gender, age and concurrent conditions affected the formulae selection. There has been strong continuity with regard to the clinical application of the most common CHM formulae and herbs for insomnia. Varied CHM formulae might be used according to the distinct phenotypes, stages and severity of insomnia that were traditionally identified as a ‘Syndrome’ or ‘pattern’. By taking together the empirical use, contemporary practice and evidence, Suan zao ren tang and Wen dan tang were the most frequently used and potentially promising candidates for further evaluation and therapeutic development. Part Three: A Quantitative Survey of CM Practitioners Assessing the EBP of CHM for Insomnia This part of the research answers the following research question: What are the CM practitioners’ attitudes, knowledge, skills, behaviours and barriers related to the EBP of CHM for insomnia? A quantitative survey of CM practitioners from the two large academic bodies of CM in Guangdong Province (China) was undertaken. Most survey participants showed positive attitudes to EBM and acknowledged the necessity of applying EBM in the field of CHM for insomnia. More than half of the participants remained conservative about their overall knowledge and skills of EBM. Less than half of participants believed they had implemented EBP of CHM for insomnia, but they appeared to be inactive in seeking clinical practice guidelines to assist in their decision-making. The top barriers to EBP included insufficient high-quality evidence, inadequate research skills to understand EBM and a lack of generalisability of the research findings to patients. Thirteen potential factors were identified that related to EBP of CHM for insomnia. The logistic regression and factor analysis determined the essential factors explaining the behaviours related to EBP of CHM for insomnia, including motivation and goals and the knowledge and skills associated with EBM. Part Four: A Qualitative Interview of CM Practitioners Exploring Their Perspectives on EBM and EBP of CHM for Insomnia The final part of the research explores in greater details the way CM practitioners perceived EBM and their behaviours related to EBP of CHM for insomnia. A qualitative interview of the CM practitioners was conducted. All the interviewees showed positive attitudes to EBM and acknowledged the benefits of EBP of CHM for insomnia. Interviewees demonstrated their understanding of EBM was in line with the commonly understood definition. Also, they understood the importance of critical thinking when they applied senior practitioners’ experience in practice, though they acknowledged the benefits of apprenticeship to improving clinical practice. The barriers to applying contemporary evidence in CM practice were explained within the context of the directness, quality and production of evidence. As a unique characteristic of CM, the principle ‘individualised treatment’ was considered to influence the decision-making and utilisation of CM evidence in EBP. The interviewees indicated that they updated their knowledge of conventional medicine by reading the latest research and clinical practice guidelines. However, they updated their CM knowledge by reading the historical literature and apprenticeship to meet needs of enhancing their clinical practice because of their similarity to clinical scenarios. Based on findings from Parts 3 and 4, a theoretical framework useful for evidence-based CM practice (EBCMP) was constructed by mixed analyses of the quantitative survey (Part 3) and qualitative interview (Part 4). The framework included four factors to improve EBCMP, namely, 1) motivation and goals for EBM, 2) belief about the consequence of EBM, 3) fundamental training of EBM and 4) capacity of EBP. It also included two CM-specific obstacles to EBCMP, namely, 1) the indirectness of CM evidence and 2) the low-quality evidence of CM. Conclusion CHM has a long history of treating insomnia and related symptoms. The key formulae and individual herbs have been consistently used in both ancient and contemporary practice. A meta-analysis indicated that there was promising evidence on the benefit of CHM formulae for improving subjective sleep quality and quantity. When compared with current pharmacotherapy and/or psychotherapy, the effectiveness of CHM was uncertain due to the risk of bias and heterogeneity of the RCTs included in the analyses. Hence, caution should be given when translating these findings into clinical decision making. A survey and an interview of CM practitioners demonstrated their overall positive attitudes towards EBP on CHM for insomnia. Capacity building on EBM and the quality of clinical evidence of CM have been identified as major gaps for promoting EBP. Based on these findings, a theoretical framework has been proposed for enhancing EBCMP. Further evaluation on the effectiveness of this framework is required to strengthen the EBP in CHM for insomnia. Knowledge gained from this process will be transferrable to the global development of CM as a form of EBP that meets the public expectation of evidence generation, evaluation and translation (eGET)