12. PICO Annotation

This chapter is an overview or introduction to PICO Annotation. For full and more detailed guidance it is necessary to consult the Annotation Knowledge Base space in Confluence. For general questions and discussion you should use our #annotation channel in Slack.


PICO annotation is part of the Cochrane Linked Data Project. The main work on this project began in 2016 with funding received from the Gates Foundation. We were required to annotate all maternal and child health reviews. The Groups involved were Neonatal, Pregnancy & Childbirth and the Child Health Field. From 2017 to date most Groups are annotating their reviews, and some are doing so with help from the metadata specialists in the team. PICO annotation is now a task on the review production workflow in Archie.

What are we annotating

We are PICO annotating our systematic reviews of interventions. There are three sections within the reviews which can be annotated:

  1. Methods
  2. Included studies
  3. Meta-analyses
Example of an inclusion criteria in a methods section:
P (patient/condition) I (Intervention) C (Comparison) O (Outcomes)
People with asthma Yoga Usual care
Quality of life
Symptom scores

To date (March 2019), for most topics, we have only focused on ‘Methods’ however we do aim to annotate the studies and analyses in the future.


The objectives of the PICO annotation project are:

  • To develop a complete set of PICO annotations at question, included study, and analysis levels
  • To add the annotation task to the workflow in Archie
  • To complete scoping of core APIs for external business cases and data feeds
  • To engage with and train CRG staff as required (particularly Information Specialists) in key areas relevant to linked data tools and annotation work

Why are we doing it

PICO annotations data will help discoverability of evidence in the Cochrane Library and will interact with workflows in Archie, RevMan and the CRS. 

Cochrane vocabulary browser

The browser allows searching of the Cochrane vocabulary which we have developed and are continuing to refine. We began by importing selected terms from four vocabularies and have been refining by changing labels to ones more appropriate for Cochrane. Also we have been merging synonymous concepts into a single concept, adding synonyms to concepts as necessary and linking to other relevant taxonomies such as MeSH and others are under consideration.

You can search the browser to find relevant terms that you might wish to include in the annotation. You can navigate within the tree structures to find information on the broader and narrower terms available. Each term lists reviews or studies that have used that term. When a term is not available in any of these taxonomies we create a new term.

The browser will continue to be developed and grows as more reviews and studies are annotated by Groups.

Best Practice

The Information Specialists from the Oral Health and Airways Groups have documented here how they organise their annotation work. Definitely worth reading especially if annotation is new for you! Please feel free to share your Best Practice either via the #annotation channel in Slack or contact Deirdre Beecher dbeecher@cochrane.org.


  •  Chris Mavergames - Head ITS/Chief Information Officer
  •  Lorne Becker - Product Owner
  •  Deirdre Beecher - Senior Metadata Specialist
  •  Anna Last - Medical Terminology Manager
  •  Carol Friesen - Metadata Specialist
  •  Ahmad Ali - Project Manager
  •  Software developers Data Language

How do I get started

Please contact CIS Support cis-support@cochrane.org or Deirdre Beecher dbeecher@cochrane.org.