Sources of evidence for systematic reviews of interventions in diabetes

Abstract

A search of only the medline database is insufficient for systematic reviews of diabetes, because in about 34% of reviews the missed trials could affect the results of the meta-analysis. It is recommended that central (on the Cochrane Library) also be searched. Scanning meeting abstracts, and seeking unpublished data are also recommended if the intervention has only recently been introduced.

The contribution of databases to the results of systematic reviews: a cross-sectional study

“…This study confirms previous methods studies demonstrating that the majority of SR trials are found in Medline [ 7 , 25 ], and that Embase is more likely than other databases to find additional relevant trials not retrieved by Medline [ 23 , 24 ]. Our study contributes evidence to support the addition of subject-specific database (PsycINFO, ERIC) for specific topics, and the contribution of Biosis in addition to Embase for clinical medicine topics.…”

The contribution of databases to the results of systematic reviews: a cross-sectional study

“…This study confirms previous methods studies demonstrating that the majority of SR trials are found in Medline [ 7 , 25 ], and that Embase is more likely than other databases to find additional relevant trials not retrieved by Medline [ 23 , 24 ]. Our study contributes evidence to support the addition of subject-specific database (PsycINFO, ERIC) for specific topics, and the contribution of Biosis in addition to Embase for clinical medicine topics.…”

Using Embase as a supplement to PubMed in Cochrane reviews differed across fields

“…12 Fourth, using Embase may alter the effect size estimates in metanalyses as previously investigated (14)(15)(16)(17)(18). This falls outside the scope of this paper and thus this study does not determine how the additional studies retrieved by Embase affected the results of the systematic review or individual meta-analyses.…”

Can we prioritise which databases to search? A case study using a systematic review of frozen shoulder management

“…These studies were demonstrated to have had a sizable impact upon the qualitative synthesis; one study had been the major source of evidence for one of the themes, and the others not been the sole source but had added breadth, depth and strength to the synthesis. A quantitative example used systematic reviews of diabetes interventions, and re‐calculated the meta‐analyses, omitting data from trials that would not have been located had MEDLINE been the only source of studies. This type of analysis would benefit the current case study by adding a pragmatic element – ‘what difference would omitting sources make to the conclusions of the review’, and would be recommended for future work.…”

The contribution of databases to the results of systematic reviews: a cross-sectional study

“…This study confirms previous methods studies demonstrating that the majority of SR trials are found in Medline [ 7 , 25 ], and that Embase is more likely than other databases to find additional relevant trials not retrieved by Medline [ 23 , 24 ]. Our study contributes evidence to support the addition of subject-specific database (PsycINFO, ERIC) for specific topics, and the contribution of Biosis in addition to Embase for clinical medicine topics.…”

Using Embase as a supplement to PubMed in Cochrane reviews differed across fields

“…12 Fourth, using Embase may alter the effect size estimates in metanalyses as previously investigated (14)(15)(16)(17)(18). This falls outside the scope of this paper and thus this study does not determine how the additional studies retrieved by Embase affected the results of the systematic review or individual meta-analyses.…”

Can we prioritise which databases to search? A case study using a systematic review of frozen shoulder management

“…These studies were demonstrated to have had a sizable impact upon the qualitative synthesis; one study had been the major source of evidence for one of the themes, and the others not been the sole source but had added breadth, depth and strength to the synthesis. A quantitative example used systematic reviews of diabetes interventions, and re‐calculated the meta‐analyses, omitting data from trials that would not have been located had MEDLINE been the only source of studies. This type of analysis would benefit the current case study by adding a pragmatic element – ‘what difference would omitting sources make to the conclusions of the review’, and would be recommended for future work.…”

The contribution of databases to the results of systematic reviews: a cross-sectional study

“…This study confirms previous methods studies demonstrating that the majority of SR trials are found in Medline [ 7 , 25 ], and that Embase is more likely than other databases to find additional relevant trials not retrieved by Medline [ 23 , 24 ]. Our study contributes evidence to support the addition of subject-specific database (PsycINFO, ERIC) for specific topics, and the contribution of Biosis in addition to Embase for clinical medicine topics.…”

Using Embase as a supplement to PubMed in Cochrane reviews differed across fields

“…12 Fourth, using Embase may alter the effect size estimates in metanalyses as previously investigated (14)(15)(16)(17)(18). This falls outside the scope of this paper and thus this study does not determine how the additional studies retrieved by Embase affected the results of the systematic review or individual meta-analyses.…”

Can we prioritise which databases to search? A case study using a systematic review of frozen shoulder management

“…These studies were demonstrated to have had a sizable impact upon the qualitative synthesis; one study had been the major source of evidence for one of the themes, and the others not been the sole source but had added breadth, depth and strength to the synthesis. A quantitative example used systematic reviews of diabetes interventions, and re‐calculated the meta‐analyses, omitting data from trials that would not have been located had MEDLINE been the only source of studies. This type of analysis would benefit the current case study by adding a pragmatic element – ‘what difference would omitting sources make to the conclusions of the review’, and would be recommended for future work.…”