Search procedure and data extraction for meta-analysis in biomedical research

Abstract

The meta-analysis provides a unique scientific conclusion with precise statistical analysis of pooled data extracted from previously reported relevant studies. That gives a better insight into the current issue with more statistical certainty than any single study observation in biomedical research. Occasionally, meta-analyses don’t provide a precise time for each step of the search strategy. The complete meta-analysis procedure is usually time-consuming, with 6-18 months reported, but it depends on the numbers of collected articles manually reviewed by two or more researchers to prevent potential bias. The purpose of this paper was to present a part of meta-analysis research with a focus on a timeline manner for extraction procedure and suggestions for preparing the database of collected articles. PRISMA guidelines were followed, and Pub Med, Scopus, and ISI Web of Science for the search were used. EndNote reference manager v.7 and Microsoft Excel 2007 were used for base preparation. Results showed that the final reference number was 4918, and 99.88% of them were excluded. A month was necessary for the search of the electronic databases. For reading titles and abstracts and extracting the papers was needed the fourth month. A month was needed for an additional search of bibliographies of the eligible papers. Even with the dedication of the team of reviewers, it is hard to predict the exact time for conducting the meta-analysis, indeed. Our results could be applicable in planning the potential systematic reviews, with or without meta-analysis, and overcoming the obstacles in the single database preparation.