ERIC Number: EJ1256803
Record Type: Journal
Publication Date: 2017-Sep
Pages: 5
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-1759-2879
EISSN: N/A
Estimating Data from Figures with a Web-Based Program: Considerations for a Systematic Review
Burda, Brittany U.; O'Connor, Elizabeth A.; Webber, Elizabeth M.; Redmond, Nadia; Perdue, Leslie A.
Research Synthesis Methods, v8 n3 p258-262 Sep 2017
Background: Systematic reviewers often encounter incomplete or missing data, and the information desired may be difficult to obtain from a study author. Thus, systematic reviewers may have to resort to estimating data from figures with little or no raw data in a study's corresponding text or tables. Methods: We discuss a case study in which participants used a publically available Web-based program, called "webplotdigitizer", to estimate data from 2 figures. We evaluated and used the intraclass coefficient and the accuracy of the estimates to the true data to inform considerations when using estimated data from figures in systematic reviews. Results: The estimates for both figures were consistent, although the distribution of estimates in the figure of a continuous outcome was slightly higher. For the continuous outcome, the percent difference ranged from 0.23% to 30.35% while the percent difference of the event rate ranged from 0.22% to 8.92%. For both figures, the intraclass coefficient was excellent (>0.95). Conclusions: Systematic reviewers should consider and be transparent when estimating data from figures when the information cannot be obtained from study authors and perform sensitivity analyses of pooled results to reduce bias.
Descriptors: Computer Software, Internet, Literature Reviews, Data Analysis, Researchers, Reliability
Wiley-Blackwell. 350 Main Street, Malden, MA 02148. Tel: 800-835-6770; Tel: 781-388-8598; Fax: 781-388-8232; e-mail: cs-journals@wiley.com; Web site: http://www.wiley.com/WileyCDA
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A