The I in PICO describes the intervention in a review or study which includes, treatments, adjunctive therapies, medications, diagnostic tests or recommendations for patients. The C in PICO describes the comparison in a review or study which is the alternative or standard treatment to be compared to the experimental intervention. Most of the principles for annotating Comparisons are the same as those for Interventions.
Materials or Procedures (interventions)
All drugs
In many reviews authors include any drug within a specific drug category or categories.
- use the drug classification
example: DrugCategory - Immunoglobulins
Any intervention
Sometimes the intervention will be stated as any intervention.
- omit the controlled vocab term
- annotate the intervention modifiers (if there are any)
- leave the classification heading blank/unselected if not specified
Combination drug terms
- Annotate with the two or more separate drugs or drug categories using AND
example: Favipiravir Combined With Tocilizumab - Favipiravir AND Tocilizumab
- Exception: combination drugs where the combination is widely known as as single medication
example: Lopinavir And Ritonavir which is known as Kaletra
Dose, schedule and duration
If this information is not available or not required the fields remain empty.
Some review questions will focus on
- dose comparisons between different interventions and comparisons
- comparison of specific doses of the same drug
Injections
- choose injection as a delivery method modifier for the intervention
- use more specific injection terms in the delivery method modifier section if indicated in the review text
Classification categories
For both the Intervention and Comparison components there is a 15 item classification of interventions from Davey et al.
This classification is built upon the Health Research Classification System developed by the UK Clinical Research Collaboration.
New group/arm - how and when to use
Some studies are designed to compare several interventions with one another so that there is no single Comparison. These studies are referred to as multi-arm studies and each “arm” of the study receives one of the interventions.
Multi-arm study
If authors of a review state no clear Comparison each of the arms should be annotated as a New Arm in the Intervention
- use the ‘add new arm’ function to indicate different interventions that are to be compared with one another
- Comparison should be left blank
- if a Comparison is clearly identified it should be annotated in the Comparison
Two-arm study
- There may not be a clearly identified Comparison but review authors may want to look at studies comparing two different interventions with one another
- Annotation is the same as for multi-arm studies
Studies split by review authors
- Typically there should be one study annotation for each included study in a given review
- Each row in the a review's PICO Characteristics of Included Studies table represents one study, however, some review authors have split up their description of a multi-arm trial into two or more rows
Where authors have split a multi-arm study into different rows
- only one of the rows needs to be annotated
- the data from the other arm(s) should be added to the one you are annotating
CD004217: Pain relief for neonatal circumcision
This was a 3-arm trial that the authors split into 2 rows in the Included Studies table. The Stang-1988A row describes arms 1 and 3 of the trial, and the Stang-1988B row describes arms 2 and 3 (these were the 2 relevant comparisons from the study that were used in the Review).
In this example, either Stang-1988A or Stang-1988B could be annotated as a 3 arm trial and the other row left without an annotation. Stang 1988-A was annotated.
