The Preliminary Study On Developing Methodological Guideline For Case-control Study In Traditional Chinese Medicine

Objective1. To find the existing problems of case-control studies for traditional Chinese medicine(TCM) in methodological aspect by overall searching the published case-control studies for TCM, and formulate the item pool that need to be questioned, which lays the foundations of the next work that makes the standards procedures of case-control study in the fields of TCM.2. The first round to evaluate the items by the style of consulting experts, then formed the second round items to be questioned, and draw up methodological guideline for TCM researches at last.Methods1. Systematic ReviewSearching the published case-control studies for TCM thoroughly by the way of electronic databases, and use the method of quality evaluation according to the Cochrane recommendation to evaluate the quality of the literatures. At the same time, concluding and analyzing the literatures by applying the methods of qualitative description, and offering the materials for setting up the item pool of experts consultation.2. Expert consultationEvaluating the importance of items by using the general international Delphi method, and adopting the style of expert consultation for the first round. Meanwhile, the experts can raise their opinions and suggestions about the items. Finally, confirming the included items according to the results of expert consultation and providing the draft for the second round.Results1. Systematic Review178studies meeting the including standards were identified (176Chinese literatures and2English literatures). Through synthetically evaluating the risk bias of every study, we found the literatures of low quality (3-4score) account for14.6%(26studies), the literatures of moderate quality (5-6score) account for62.9%(112studies), and the literatures of high quality (7-8score) account for22.5%(40studies). The total quality of literatures was acceptable and the amount of literatures of moderate quality was much more, while the high were smaller. The Chinese patterns of syndrome, symptoms, constitution, gene and the blood test indexes were the study focus in the field of exposure. Of11studies used the fixed records to identify the exposure. There were about21%(37studies) that selected controls from the same population of the cases. The blinding method was used in6studies to avoid the bias from investigator. The results of systematic review offered the valuable materials for the following establishing the item pool of expert questionnaire.2. Expert consultationAccording to the results of literature search and systematic review, combining the STROBE guideline of observational studies and other procedures of methodological guidelines, we formulated the questionnaire including45items. The recovery rate of the questionnaire was81.8%, so was the specialist active coefficient. The opinion of concentration index from experts had better consistency, suggesting opinion concentration of experts was better. All coefficient of variation(CV) were<0.3, suggesting coordination degree of experts was better. Of36experts from inside and outside Guangdong province participated the survey. The results showed that36items (mean score>=4) were included in the next round, and9items(3<=mean score<4) had the possibility to be included. The detailed information of the possible items to be included was as follows:3items in the choosing the patients;2items in the choosing control group;1item in the not matched case-control study;1items in the individual matching;2items in the bias and control. The identification about time point of syndrome and constitution were questioned more.Conclusion1. Through systematic review, the overall quality of case-control studies for TCM was acceptable and the amount of literatures of moderate quality was much more, while the high were smaller. In addition, case-control study itself had the defects, so it was essential to establish the guideline for this field to guide the researchers to do the high quality and high lever studies.2. It has its own particularity of case-control studies for TCM in accordance with the results of expert consultation, especially Chinese patterns of syndrome and constitution consequently, methodology aimed to enhance the guidance for such research can play a promoting role. Finally,36items were included in the next round, and9items had the possibility to be included.