The decision between data collection using paper forms and data collection using electronic forms is largely down to review authors’ preferences. Potential advantages of paper forms include:
Convenience or preference;
Data extraction can be undertaken almost anywhere;
Easier to create and implement (no need for computer programming or specialist software);
Provides a permanent record of all manipulations and modifications (providing these manipulations and modifications are not erased);
Simple comparison of forms completed by different review authors.
Potential advantages of electronic forms include:
Convenience or preference;
Combines data extraction and data entry into one step;
Forms may be programmed (e.g. using Microsoft Access) to ‘lead’ the author through the data collection process, for example, by posing questions that depend on answers to previous questions;
Data from reviews involving large numbers of studies are more easily stored, sorted and retrieved;
Allows simple conversions at the time of data extraction (e.g. standard deviations from standard errors; pounds to kilograms);
Rapid comparison of forms completed by different review authors;
Environmental considerations.
Electronic systems have been developed that offer most of the advantages of both approaches (including the commercial SRS software). If review authors plan to develop their own electronic forms using spreadsheet or database programs, we recommend that (i) a paper form is designed first, and piloted using more than one author and several study reports; (ii) the data entry is structured in a logical manner with coding of responses as consistent and straightforward as possible; (iii) compatibility of output with RevMan is checked; and (iv) mechanisms are considered for recording, assessing and correcting data entry errors.