Creating an animated video summary of a Cochrane review

After reading Jani’s blog post on creating Cochrane infographics I thought I would try and produce one for our most recent review: Needle size for vaccination procedures in children and adolescents. I soon encountered several obstacles created by the complexities of the review which involved:

  • multiple comparisons (long versus short needles, wide versus narrow needles)
  • multiple patient-relevant outcomes (immune response, pain, crying, local reactions, other adverse events after vaccination)
  • varying quality of evidence (GRADE) ratings across outcomes.

My attempts to address these issues resulted in a messy infographic that contained too many images and an excessive amount of explanatory text. I eventually abandoned the infographic and decided to create a video that would incorporate a voice-over to deliver additional information that could not be communicated by a static combination of images and text alone. You can have a look at the finished product below:

I developed the video in four stages:

Stage 1: Drafting the voice-over (narration) script for the video

I used the Plain Language Summary (PLS) of the review as a template for the voice-over script which I divided into four sections:

1) Introduction/Background
2) Review questions
3) Study characteristics and quality of the evidence
4) Key findings.

I drew up a table for each section that contained a draft of the voice-over script and an outline of appropriate visuals that could be used to communicate the key messages. It is essential to plan the narration and visuals for the video simultaneously because you will need to deliver the voice-over at a pace that will allow sufficient time for any accompanying images and text to appear on the screen. An extract from the table that I used for the Introduction/Background section is illustrated below:


Once I had completed a Table for each section, I then read the entire voice-over script aloud from start to finish several times. Reading aloud is a great way to identify words and phrases that don’t ‘sound right’ and can also help to identify transitions from one sentence to the next that are not as smooth as they should be. After multiple edits I finally had a workable voice-over script for the video of about six minutes in duration.

Stage 2: Recording the voice-over script

I recorded the voice-over on my office PC using a basic USB microphone and Audacity® – a free software programme for sound recording and editing. During the recording I read the script at a relatively slow pace and tried to ensure that there were appropriate pauses where I intended new images or text to appear on the video. I carried out some basic post-recording editing using Audacity® to remove unwanted background noise (including the annoying ‘hum’ from the air-conditioning in the office). I saved the final voice-over as a WAV (Waveform Audio) file.

Stage 3: Making the video

I used Camtasia® screen capture and video-editing software to create the video. I have been using Camtasia® for several years and have found it one of the easiest video-creating tools to navigate and work creatively with (I should mention at this point that I have no vested interests to declare in relation to any products mentioned in this post!).

The first step in making the video involved importing the voice-over audio file and all of the images that I intended to use into Camtasia®. I obtained the images from multiple sources including creative commons license images located using Google images and free clip art sites such as I also purchased some royalty-free images via subscriptions to shutterstock and PresenterMedia. I customised some of the images in PowerPoint (e.g. I ‘cropped’ some images to remove unwanted parts) before finally importing into Camtasia®.

Once the importation process was completed, I added the audio file to a ‘track’ on the ‘timeline’ (see below). I then added images to different tracks and positioned them on the timeline to ensure that they were appropriately synchronised with the voice-over. This process was very time-consuming but it was not technically difficult to do – Camtasia® has an intuitive, easy-to-use interface and the product website also includes numerous tutorials that show you how to navigate the various settings and use basic and advanced video editing techniques.

Paul Beirne's pic1

Deciding how to present the key findings of the review was one of the most challenging aspects of creating the video. I opted for a modified version of a Summary of Findings Table (see below) that contained details of the outcomes, the GRADE quality of evidence ratings and a narrative summary of the key findings. For simplicity, and in keeping with the presentation of results in the Plain Language Summary of our review, I did not include any numerical data in the table. I used Source Sans Pro typeface for the text in accordance with Cochrane branding guidelines.

Paul Beirne's pic2

Stage 4: Adding the finishing touches and producing the video

Having synchronised all images and accompanying text with the voice-over, I used editing tools in Camtasia® to add some visual effects, including ‘transitions’ to create a smoother flow between different sections of the video. I also inserted arrows and highlighted text at selected time points to draw the viewer’s attention to specific parts of the screen. At the beginning and end of the video I added a ‘handwriting effect’ created using the whiteboard software VideoScribe®. I saved the handwriting effect as a Quick Time Movie (.mov) file and then imported it into Camtasia®. Finally, to remove any ‘awkward silences’ at the start and finish of the video, I added a repetitive guitar riff which I played on my acoustic guitar and recorded directly into Camtasia®.

With the finishing touches added, I was now ready to produce and share the video. Camtasia® allows you to you to upload your video immediately on YouTube, Vimeo and, provided that you have already registered with these sites. You can also use Camtasia® to produce the file in several formats including MP4, WMV (Windows Media video), MOV (QuickTime movie), AVI (Audio Video Interleave video file), M4V (iPod, iPhone, iTunes compatible video) and GIF (animation file). I chose MP4 format as this offers a good quality video with a relatively small file size and it plays on most desktop browsers, smartphones and tablets.


The findings of some Cochrane reviews may be challenging to present in an infographic. As a previous contributor to Visually Cochrane has noted: “where there are multiple comparisons, lots of outcomes or no clear findings it becomes much more difficult to summarise the review visually.” In these circumstances an alternative approach is to consider combining images with narration in a video format. I hope this post has given you some useful hints regarding how to develop such a video. Other helpful tips for producing a Cochrane animated video can be found in another blog post in the Cochrane Community Archive.

Good luck in your creative endeavours!

Paul Beirne

Paul is a Cochrane review author and teaches epidemiology to public health students at University College Cork, Ireland.


5 thoughts on “Creating an animated video summary of a Cochrane review

  1. This is was a great way to “consume” a Cochane review. It looked extremely professional and well-produced, and the instructions on how to create it are brilliant. Will this go on the Cochrane Training site? I thought that the information about poor quality of the evidence on many important outcomes, and the fact that the only vaccine used in the trials was one used in developing countries was an important one. So perhaps the illustration of a very white baby could therefore be re-thought as well to help get that message across? It creates a dissonance between what you are seeing (a white baby) and the narration which says that the trials in the review have been done using a vaccine only used in developing countries and might not apply outside this context. So now I am a bit confused. Also, could the outcomes such as development of a fever be linked to the length and guage of needle used? Surely that will depend on the type of vaccine, and I wouldn’t really expect that to be measured as an outcome related to the pain of the injection.


  2. Hi Caroline, thanks a million for the feedback – much appreciated!
    The image of the baby is introduced in the context of a brief description of the trial participants, the injection technique and the types of vaccines used in the trials. Two of the trials (815 participants) were conducted in General Medical Practices in the Vale of Aylesbury, Buckinghamshire and North East Oxfordshire areas of England (only 3 out of 26 General Medical Practices participating in the trial were located in areas with a high proportion of ethnic minority families). These trials were conducted prior to the change in the UK primary immunisation programme from “whole-cell” pertussis vaccines to “acellular” pertussis vaccines. Acellular pertussis vaccines have gradually become the predominant type used in industrialised countries whereas whole cell vaccines are used in many developing countries as they are considerably less expensive. It wasn’t feasible to incorporate these contextual details into the short video…..but I agree that the image creates a disconnect between the visuals and the narration and I will need to think about how to modify the video to address this!

    Regarding the issue of fever, you are right that this will depend on the type of vaccine. However, the length of the needle may influence where the vaccine is deposited and this could potentially impact on the incidence of post-vaccination fever. Many vaccines contain adjuvants (substances such as aluminium salts that are added to vaccines to increase the body’s immune response) and it is normally recommended that such vaccines are injected into muscle to reduce the risk of local adverse events. The use of a short needle may result in inadvertent vaccine administration superficial to muscle (e.g. into the subcutaneous tissue) and this can lead to irritation/inflammation and, potentially, granuloma formation and necrosis. Any resultant inflammatory responses could be accompanied by fever. There are lots of ‘ifs and maybes’ in the preceding text but nevertheless some trials investigating the effects of using needles of different sizes for vaccination procedures have included fever as an outcome measure. Three of the trials included in our review reported the incidence of post-vaccination fever but due to the very low quality of the evidence we weren’t able to draw any conclusions.
    I hope this addresses your questions. Thanks again for the feedback.
    All the best, Paul


  3. Hi Paul,
    I really like your summary of this review. There are definitely advantages to presenting more complex comparisons like this over an infographic (although it sounds pretty labour-intensive to produce!). I hope it helps people to access the evidence and helps their understanding of the review.
    Best wishes, Helen


  4. Hi Helen,
    Thanks so much for the positive feedback. You’re right, the video was labour–intensive to produce; but I hope the end product was worth the effort and that it makes the evidence more accessible to a wider audience.
    All the best ,


  5. Pingback: Quo Vadis Cochrane visualisation? | visually cochrane

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