Hong Quan Nha, Pluye Pierre, Bujold Mathieu, Wassef Maggy
Department of Family Medicine, McGill University, 5858 Chemin de la Côte-des-Neiges, 3rd Floor, Montreal, QC, H3S 1Z1, Canada.
Information Technology Primary Care Research Group, Department of Family Medicine, McGill University, Montreal, QC, Canada.
Syst Rev. 2017 Mar 23;6(1):61. doi: 10.1186/s13643-017-0454-2.
Systematic reviews of qualitative and quantitative evidence can provide a rich understanding of complex phenomena. This type of review is increasingly popular, has been used to provide a landscape of existing knowledge, and addresses the types of questions not usually covered in reviews relying solely on either quantitative or qualitative evidence. Although several typologies of synthesis designs have been developed, none have been tested on a large sample of reviews. The aim of this review of reviews was to identify and develop a typology of synthesis designs and methods that have been used and to propose strategies for synthesizing qualitative and quantitative evidence.
A review of systematic reviews combining qualitative and quantitative evidence was performed. Six databases were searched from inception to December 2014. Reviews were included if they were systematic reviews combining qualitative and quantitative evidence. The included reviews were analyzed according to three concepts of synthesis processes: (a) synthesis methods, (b) sequence of data synthesis, and (c) integration of data and synthesis results.
A total of 459 reviews were included. The analysis of this literature highlighted a lack of transparency in reporting how evidence was synthesized and a lack of consistency in the terminology used. Two main types of synthesis designs were identified: convergent and sequential synthesis designs. Within the convergent synthesis design, three subtypes were found: (a) data-based convergent synthesis design, where qualitative and quantitative evidence is analyzed together using the same synthesis method, (b) results-based convergent synthesis design, where qualitative and quantitative evidence is analyzed separately using different synthesis methods and results of both syntheses are integrated during a final synthesis, and (c) parallel-results convergent synthesis design consisting of independent syntheses of qualitative and quantitative evidence and an interpretation of the results in the discussion.
Performing systematic reviews of qualitative and quantitative evidence is challenging because of the multiple synthesis options. The findings provide guidance on how to combine qualitative and quantitative evidence. Also, recommendations are made to improve the conducting and reporting of this type of review.
对定性和定量证据进行系统评价能够深入理解复杂现象。这类评价日益普遍，已用于呈现现有知识的全貌，并解决仅依赖定量或定性证据的评价通常未涵盖的问题类型。尽管已开发出多种综合设计类型，但尚未在大量评价样本上进行检验。本综述的目的是识别并开发已使用的综合设计和方法类型，并提出综合定性和定量证据的策略。
对结合定性和定量证据的系统评价进行综述。检索了6个数据库，检索时间从建库至2014年12月。纳入的评价需为结合定性和定量证据的系统评价。根据综合过程的三个概念对纳入的评价进行分析：（a）综合方法，（b）数据综合的顺序，以及（c）数据与综合结果的整合。
共纳入459篇评价。对该文献的分析突出显示，在报告证据如何综合方面缺乏透明度，且所用术语缺乏一致性。识别出两种主要的综合设计类型：收敛式和序列式综合设计。在收敛式综合设计中，发现了三个子类型：（a）基于数据的收敛式综合设计，即使用相同的综合方法对定性和定量证据进行共同分析；（b）基于结果的收敛式综合设计，即使用不同的综合方法分别对定性和定量证据进行分析，并在最终综合过程中整合两种综合的结果；（c）平行结果收敛式综合设计，包括对定性和定量证据进行独立综合，并在讨论中对结果进行解释。
由于存在多种综合选项，对定性和定量证据进行系统评价具有挑战性。研究结果为如何结合定性和定量证据提供了指导。此外，还提出了改进这类评价的实施和报告的建议。
