Systematic review vs meta-analysis | What’s the difference?

You may ask, what is the difference between a systematic review and a meta-analysis? Or, is a systematic review the same as a meta-analysis? In this video, I’ll explain what a systematic review and meta-analysis is by using an example.

A researcher may study the effectiveness of balance exercises after an ankle sprain on the time it takes to go back to football practice. The researcher team will analyse the results by comparing the time taken to return to practice between the group who did the balance exercises and the group who did not do any home exercises and publish their findings in an academic journal. This study is referred to as a primary or empirical study.

Over time, many research groups generate new knowledge by performing similar primary studies worldwide. Therefore, there may be more than one study that investigates, for example, the effectiveness of balance exercises after an ankle sprain. These primary studies may be done on different populations, let’s say, some in adolescent football players, others in female football players, others in hockey players, others in university students, and so on. Then, a group of researchers with a special interest in balance exercises will come along and realise that there are so many primary studies on the effectiveness of balance exercises that they decide to conduct a systematic review. The research group will then take all these primary studies and, using a very systematic process, to summarise the findings into one research paper, and this study design is referred to as a systematic review.

There are many different types of systematic reviews, and in this video, I only referred to a systematic review of effectiveness. You even get Umbrella reviews which are systematic reviews of systematic reviews. You’ll find more information on the various types of systematic reviews in another video on the Research Masterminds YouTube channel.

The researchers who conduct the systematic review may do a meta-analysis as part of the systematic review. A meta-analysis is done by taking the results from each primary study, pooling these results together and re-analyse them to look at the effectiveness of balance exercises across all studies. A meta-analysis can’t always be done. To do a meta-analysis, the primary studies that are being pooled together, need to be similar enough to one another. Or in some cases, the primary studies consist of qualitative data, where for example, interviews with participants were done, in which case no statistical analysis can be done.

How do you know whether it’s a systematic review or a systematic review with a meta-anaysis? You’ll often see that the title of the publication states whether it’s a systematic review or a systematic review and meta-analysis, although this is not always the case and then you may pick up from the abstract whether a meta-analysis was also done. If its still not clear, you can go to the methods and results section to see if the results from all these studies were analysed statistically.

To summarise, a systematic review refers to the summarising of primary studies into one study, using rigorous and systematic methods, while a meta-analysis refers to the statistical analysis used to pool all the findings from the different primary studies into one analysis. Not all systematic reviews include a meta-analysis, but all meta-analyses are part of a systematic review.

If you have any questions around a systematic review, see if you can find the answer amongst the other videos in the Systematic Reviews playlist on the Research Masterminds YouTube Channel. Feel free to ask a question by posting it in the comment box below this video.

[v_kid_]

Tomorrow is my final exam you are a life savior

[adakuemeruem]

Thank you very much for this clear explanation!

[jennyrai]

If you are citing mortality analysis of one specific animal lets say snow leopard what type of study is it ?

[vorak]

Thank you. Very good explanation and helped a lot. So whenever the researcher says he or she is using a regression model to analysis, he is performing a meta-analysis or can a regression model be used for a regular primary study? What is the difference between a regression model approach and a matching method?

[daniabatool]

I wanna know about Meta-Review...I think it is the review of systematic reviews or meta-analyses....I wanna know what components does its research proposal and thesis consist of?

[taufikikhsan]

Thank you for the video, it really helps to start understanding the difference between lit review and meta-analysis. A question though, I wonder the differences (if exist) between those two methods in terms of the contributions to a field. How do they differ? And what's the first indicator of a good quality meta-analysis paper? Thank you

[iamgoku]

South African accent recognisable anywhere in the world ❤

[artsafonov]

Thanks a lot. Could you advise some programs for meta-analysis ?

[paolabiazin]

Thanks! A question.. which are the regress methods used in a systematic reviews?

[iqx]

meta ... summary of summaries (papers)

[tmrwic]

Does it mean systematic reviews (without meta-analysis) make a conclusion without statistics? I'm a little confused.Thanks very much for your reply. :) :)

[Wfb_DVM]

Is a systematic review the same as a literature review?