Extracting numerical data from published reports of pharmacokinetics investigations: method description and validation.

A method has been proposed for extracting numerical data when only graphical results are presented. Reports with both graphical and tabular data were identified and the graphs were electronically scanned. The coordinates of each point were read using the cross-hair facility of Adobe Photoshop 7.0. To improve the precision of these coordinates, each point was read at 1600% magnification. The agreement between the observers was almost perfect (R > 0.99). The proposed method makes possible use of data in meta-analyses that, would otherwise be discarded.