TABLE OF CONTENTS

• Scope of Use for This Data Extraction Form
• Overview of the Data Extraction Form
• Data extraction process
  • Subsections with examples
  • Vocabulary fields
• Tabs description
  • Study characteristics tab
  • Methods tab  
  • Search results tab  
  • Outcomes tab
  • Outcome per included studies tab
  • Quality Assessment of Systematic Review tab
  • Finalize

Scope of Use for This Data Extraction Form

This data extraction form is designed for use in reviews of a broader scope (i.e. umbrella reviews/review of reviews/overview). The aims can include:

• Extracting cumulative information and summation metrics from secondary studies, especially systematic reviews, in order to e.g. undertake narrative summaries 

• Extract primary studies analyzed in a systematic review together with their outcomes of interest

Data can be extracted from both primary studies and secondary evidence, such as published systematic reviews.

Overview of the Data Extraction Form

The Extraction Form is divided into tabs:

• Study characteristics - general information about the study, e.g. type of report, study objectives and limitations,

• Methods - inclusion and exclusion criteria linked to PICO elements, study arms and databases searched

• Search results - details on a searches results conducted within a secondary study

• Outcomes - summative/cumulative outcomes reported in a secondary study, e.g. results of a metaanalysis

• Outcome per included studies - results reported in individual primary studies included in analysed secondary study

• Quality Assessment of Systematic Review - AMSTAR 2, embedded appraisal questionnaire to assess the methodological quality

Extraction Summary: You will be able to efficiently export only the specific types of data relevant to your needs. The extracted data will be categorized according to data type in tabs.

Data extraction process

Subsections with examples

In each tab you will find different Sections with data extraction fields with or without subsections. Such organised structure enables precise determination of dependencies between elements (extraction fields). All three types of subsections are used in the Outcomes tab. To learn more about the structure of data extraction forms click here. 

Example 1: For comparison

Choose the study arms being compared and the direction of comparison (e. g. intervention vs placebo or placebo vs intervention), then extract the value (i.e. result of a metaanalysis).

Example 2: Basic subsection

Extract the IDs of studies being analysed for a given outcome. 

Example 3: For group level data

Extract the information related to the given study arm, here total number of patients included in each study arm for analysed outcome.

Vocabulary fields

Most of the data extraction fields are text fields, such as those used for extracting numerical values. However, some sections include vocabulary fields, where reviewers select data from a predefined list. During extraction, each reviewer has permission to create new codes if needed.

Tabs description

Study characteristics tab

This tab is dedicated to extract information about the characteristics of the study, such as its type, funding source, objectives and limitations. 

Methods tab  

This tab is dedicated to extracting information such as inclusion and exclusion criteria, and linking them to PICO elements along with information on the study arms and databases searched.

It includes five sections:

• Inclusion criteria

• Exclusion criteria

• Study arms

• Databases

The inclusion and exclusion criteria sections are designed in such a way as to allow the linking of a given criterion to the PICO element. This facilitates comparison of the scope of systematic reviews.

Before proceeding with further tabs, it is important to extract information to the 'Study Arms' section. This is because the sections within the 'Outcomes' tabs are connected, and this ensures that the outcome atributes are correctly defined.

Search results tab  

This tab is dedicated to extract details on search results conducted within a secondary study.

Outcomes tab

This tab is dedicated to extract summative/cumulative outcomes reported in a systematic review, e.g. results of a metaanalysis.

Please note that it is essential to extract information to the 'Study arms' section first. The labels within the 'Comparison' and 'Per study arms' subsections can only be generated properly if information from the 'Study arms' section is provided.

In the 'Studies Analysed' subsection, extract the IDs of the studies that analysed the given outcome. In this example, the outcome is 'adverse events'. 

Outcome per included studies tab

This tab is dedicated to extracting results reported in individual primary studies included in analysed secondary study.

It contains two sections:

• Included studies section where you can extract IDs of all studies that were analysed within given secondary study

• Overall outcomes per included study section designed to extract outcome values reported within given primary study

Please take special attention to set appropriate Connection after extracting outcomes per included study, specifically to define which study given outcome relates to. The list of studies ID is generated based on information extracted in the previous section (Included studies).

Quality Assessment of Systematic Review tab

This tab is dedicated to conducting quality and risk of bias analyses. The embedded appraisal questionnaire, intended for evaluating methodological quality, is aligned with the AMSTAR 2 framework.

Finalize

Once you have finished extracting the data, click on the 'Finalize' button. The tool will notify you if any information is missing. You can finalise the extraction anyway or go back to the suggested fields to verify them.