Article type
Year
Abstract
Background: Cluster-randomized controlled trials (CRTs) have greatly increased over the past 20 years and have motivated the publication of an extension of the CONSORT statement for this design because of its particular methodological issues. However, there are few systematic reviews (SRs) or meta-analysis of CRTs that have been conducted or published.
Objectives: To address key questions when conducting SRs of CRTs.
Methods: We searched MEDLINE, Embase, the Cochrane Library, CNKI (China National Knowledge Infrastructure/Chinese Academic Journals full text Database), VIP (a Chinese full-text database), WANFANG (a Chinese full-text database) and CBM (China Biomedicine Database Disc) using the term cluster*, group*, field*, community, communities, systematic review*, meta analysis in titles on 16 January 2015. We also checked the section about CRTs in the Cochrane Handbook for Systematic Reviews of Interventions.
Results: We identified 696 papers but only four were relevant to SRs of CRTs. The main challenges of systematic reviews and meta-analysis of CRTs are how to:
1. develop highly sensitive search strategies for SRs of CRTs;
2. assess the particular risk of bias of CRTs;
3. deal with CRTs with different types of clusters;
4. choose statistical methods to combine the results;
5. combine the findings from CRTs;
6. conduct the subgroup analysis;
7. consider intracluster (or intraclass) correlation coefficient (ICC);
8. GRADE the evidence, such as recruitment bias, in CRTs;
9. explain the difference when cluster- and individually randomized trials in an SR are inconsistent for the same topic;
10. generalize the findings.
Conclusions: The SOC(systematic reviews of cluster randomized trial) Working Group has already explored highly sensitive search strategies for SRs of CRTs. We expected to work together with methodologists, researchers using CRTs and statisticians to develop a more detailed guideline for systematic reviewers of CRTs.
Objectives: To address key questions when conducting SRs of CRTs.
Methods: We searched MEDLINE, Embase, the Cochrane Library, CNKI (China National Knowledge Infrastructure/Chinese Academic Journals full text Database), VIP (a Chinese full-text database), WANFANG (a Chinese full-text database) and CBM (China Biomedicine Database Disc) using the term cluster*, group*, field*, community, communities, systematic review*, meta analysis in titles on 16 January 2015. We also checked the section about CRTs in the Cochrane Handbook for Systematic Reviews of Interventions.
Results: We identified 696 papers but only four were relevant to SRs of CRTs. The main challenges of systematic reviews and meta-analysis of CRTs are how to:
1. develop highly sensitive search strategies for SRs of CRTs;
2. assess the particular risk of bias of CRTs;
3. deal with CRTs with different types of clusters;
4. choose statistical methods to combine the results;
5. combine the findings from CRTs;
6. conduct the subgroup analysis;
7. consider intracluster (or intraclass) correlation coefficient (ICC);
8. GRADE the evidence, such as recruitment bias, in CRTs;
9. explain the difference when cluster- and individually randomized trials in an SR are inconsistent for the same topic;
10. generalize the findings.
Conclusions: The SOC(systematic reviews of cluster randomized trial) Working Group has already explored highly sensitive search strategies for SRs of CRTs. We expected to work together with methodologists, researchers using CRTs and statisticians to develop a more detailed guideline for systematic reviewers of CRTs.