Today we release the third iteration of our evidence and gap map (EGM) on effectiveness. When we first created our evidence and gap maps in 2018 in partnership with the Campbell Collaboration, our aim was to bring together the different types of evidence on homelessness in one place, to give the people who need it an overview of the existing evidence base. We’ve seen EGMs add real value in other fields,  so it was crucial for the Centre for Homelessness Impact to bring that value to homelessness for the first time. 

Watch our video on EGMs

What has changed since the previous version?

This update includes 134 new studies - 394 studies in total. This version of the EGM confirms that the tide may be turning when it comes to the use of evidence in homelessness. We’re delighted that there has been a significant increase in the number of evaluations conducted in the last few years, in fact 46% of all the studies included in the EGM are from the last five years, and an impressive 27% are from 2018 or 2019. Although over 85% of the studies included in the map are from North America and less than 5% from the UK, the trend is moving in the right direction with a rise of over 50% in the UK since we created the map in 2018. Much of the evidence has been produced by the same institutions, with teams at University of California, University of Toronto and The Ohio State University responsible for a total of 67 of the included studies. 

Why are EGMs a fundamental piece of the evidence infrastructure? 

Because they help understand what we know and crucially - what we don’t. The gaps are as important as the evidence - it’s important to highlight what we don’t know in order to direct investment and resources to the right place. Having all the existing evidence in one place helps to avoid duplication and helps focus our attention as a field. This version of the map shows the largest gaps are for legislation, financing and communication. There is also a lack of evidence on prevention and employment. There are currently few studies related to justice indicators, public attitude and perception and cost.

Read the report

Knowing what evidence is available is only one piece of the puzzle. This version of the EGM also helps identify new areas where a substantial evidence base now exists, and we can start drawing those studies together to form an idea of what works. Key areas where studies are concentrated include addiction support, homelessness prevention through welfare and housing support, programmes that offer soft skills training and the different models of case management.  

It’s also crucial to know whether the studies are good quality. To ensure decision-making is guided by high quality evidence, we assess each study using a critical appraisal. Our interactive map clearly shows the number of studies in each area, whether they are primary studies or systematic reviews, and whether they are of low, medium or high quality.

Try the map

We know that much of the money spent on homelessness is going towards interventions that have not been rigorously evaluated, so there is no indication of whether they truly work. If we are to invest wisely in homelessness prevention, it is crucial that money is spent in the right places, and in the right way. Investing money on evidence itself is a great leap forward, and using the insights from the EGM, we can target that spending much more effectively. 

COVID-19 has made the need for an evidence-led approach to ending homelessness clearer and more urgent than ever before. There is also a need for different types of research, to help to prevent the pandemic having significant and long-lasting impacts on those experiencing and at risk of homelessness. Our hope is that the homelessness field can reflect on the findings presented in the maps and continue improving evidence on homelessness, but most importantly to embed reliable evidence and data into all of our decision-making processes and structures. 

Making reliable research available in one place in a clear, accessible way is crucial to us working towards an evidence-led end to homelessness. The need for greater emphasis on evidence in homelessness is abundantly clear and it has the potential to move us closer to a society that leaves no one behind. 

Next steps

Our evidence and gap maps are living - we will continue to develop and update them, to map where good quality evidence exists, where it is lacking, and where we urgently need to fill the gaps. 

We also encourage anyone undertaking studies in these areas to get in touch with us so we can add them to the map as soon as they are available.

You can find the report here. If you have any questions about the EGMs or the data held within them please contact us.