To meet the evidence users' requirement for qualitative systematic review, it is necessary to establish an evidence classification system for it. The Confidence of the Evidence from Reviews of Qualitative research (CERQual) approach was developed for evidence classification of qualitative systematic review. Four components contribute to the assessment in CERQual: (1) Methodological limitations: Refer to problems in the design or conduct of the primary studies which need to be evaluated by specific tools used for methodological assessment of qualitative research. (2) Relevance: Relevance is the extent to which the objective, population etc. of included studies are applicable to the review question. (3) Coherence: It is the extent to which the review finding is consistent with the results in primary studies or the patterns, differences across primary studies, were explained reasonably. (4) Adequacy of data: Refer to the degree of richness and quantity of data supporting a review finding. Finally, integrate each of the components and rate the confidence of individual review finding as high, moderate, low or very low confidence. CERQual provides a transparent method for assessing the confidence of evidence from reviews of qualitative research. It may facilitate the use of qualitative research in evidence-informed decision making and guideline development processes. This article will introduce CERQual approach in detail and give an example to explain how to use it.
Evidence-based medicine (EBM) emphasizes the combination of the physician's experience, the best research evidence and patient's values to ensure the best prevention and treatment effect. Evidence is the core of the EBM, and quantitative systematic review can synthesize interventional studies; however, it can't provide synthetic evidence for patients' demands, opinions and attitudes and so on. Qualitative systematic review can offset these limitations. With the development of methodology of qualitative research and systematic review of qualitative studies, the number of qualitative studies increased year by year and they provided more and more evidence for decision making in public health, social work, management and education. The international research institutions including the Cochrane Collaboration, the Campbell Collaboration and the 3ie have mature methods for qualitative systematic review; however, few studies introduced how to write it in China. Therefore, this paper briefly introduces how to write the qualitative systematic review.