Having identified the studies to include in your review, you need to collate the data you have found in a meaningful way. This will require some knowledge of statistical analysis techniques.
Modules 6-7 of Cochrane Interactive Learning have information on performing a statistical analysis. The Library is subscribing to Cochrane Interactive Learning.
How to analyse different types of data, effect measures, undertaking meta-analysis, recognising heterogeneity.
How to interpret results of systematic analysis, using GRADE method to report uncertainty of evidence.
A database of e-books that you can search. For example, enter the term 'statistics' or 'Excel' or the name of a statistical package such as 'SPSS'.