Article type
Year
Abstract
Background: Different conclusions may be drawn from different systematic reviews/meta-analyses on the same topic.
Objectives: We tried to investigate this condition from systematic reviews/ meta-analyses of interventional and observational studies, and its reasons.
Methods: We searched the Cochrane Library, PubMed, EMBASE, ISI Web of Knowledge, and Chinese Biomedical Literature Database about two big topics: the effects of garlic, the environment factors of gastric cancer. We just included systematic reviews or meta-analyses published before 2010 October. The numbers of systematic reviews/meta-analyses, search time, database searched, study designs, language and time restrictions, and meta-analysis software used were primary outcomes, the author number and their countries were secondary outcomes.
Results: 80 systematic reviews/ meta-analyses about 39 small topics dividing from these two big topics were found (mean: 2.05 citations for each topic), in which only 59 papers focused on two or more topics (mean: 3.28 citations for each topic). The conclusions of the papers about six topics (15.38%) were different. As the search time was different in two topics and inclusion criteria about study design were different in the remaining four, which made the number of included studies was different and finally led to different conclusions. Also, two or more systematic reviews/meta-analyses were found about one topic, but two kinds of patients, in three topics. All the 80 papers just included the studies published in English or their native languages, or both.
Conclusions: Duplicate working on the same topic wasted much resources during systematic review/meta-analysis producing and might lead different conclusions; registrations,and international collaboration could address these issues.
Objectives: We tried to investigate this condition from systematic reviews/ meta-analyses of interventional and observational studies, and its reasons.
Methods: We searched the Cochrane Library, PubMed, EMBASE, ISI Web of Knowledge, and Chinese Biomedical Literature Database about two big topics: the effects of garlic, the environment factors of gastric cancer. We just included systematic reviews or meta-analyses published before 2010 October. The numbers of systematic reviews/meta-analyses, search time, database searched, study designs, language and time restrictions, and meta-analysis software used were primary outcomes, the author number and their countries were secondary outcomes.
Results: 80 systematic reviews/ meta-analyses about 39 small topics dividing from these two big topics were found (mean: 2.05 citations for each topic), in which only 59 papers focused on two or more topics (mean: 3.28 citations for each topic). The conclusions of the papers about six topics (15.38%) were different. As the search time was different in two topics and inclusion criteria about study design were different in the remaining four, which made the number of included studies was different and finally led to different conclusions. Also, two or more systematic reviews/meta-analyses were found about one topic, but two kinds of patients, in three topics. All the 80 papers just included the studies published in English or their native languages, or both.
Conclusions: Duplicate working on the same topic wasted much resources during systematic review/meta-analysis producing and might lead different conclusions; registrations,and international collaboration could address these issues.