Methodological approaches to developing and establishing the body of evidence on post-marketing Chinese medicine safety.

Evidence based medicine demands the highest form of scientific evidence to demonstrate the efficacy and clinical effectiveness for any therapeutic intervention in order to provide best care. It is however accepted that in the absence of scientific evidence, personal experience and expert opinion together with professional judgement are critical. Obtaining evidence for drug safety, postmarketing surveillance (PMS) has focussed on follow up of observational cohorts exposed to a particular drug in order to estimate the incidence of adverse drug reactions (ADRs). Evidence on PMS of Chinese herbal products is still limited, in particular for herbal injections. The aim of this article is to suggest a new model of ascertaining the safety of Chinese medicine using a more comprehensive approach for collecting data. To collect safety data on the Chinese herbal injection, Kudiezi, a mixed methods approach is proposed using 18 hospital information systems to detect ADRs in order to prospectively observe 30,000 patients over 3 years. Evidence will also be collected using a questionnaire survey and through a sample of semi structured interviews. This information based on the expert opinion and the experience of clinicians will produce additional data on the frequency and types of side effects in clinical practice. Furthermore semi structured interviews with a random sample of patients receiving the injection will be carried out to ascertain any potential side effects missed. It is hoped that this comprehensive approach to data collection will accumulate wider evidence based on individual traditional Chinese medicine care and treatment and provide important feedback to the national data collection system to ensure completeness of ADR data recording, monitoring and any potential wider effects through developing improved ADR guidelines.