Universities in England are being urged to work together to ensure young people from less advantaged homes succeed in their degree studies.
The Higher Education Funding Council for England (Hefce) says while there is isolated work going on in individual institutions, it is "fragmented".
As a result there is a lack of detailed evidence on which interventions achieve the best results for different groups.
However, access to university continues to improve for disadvantaged students.
Hefce analysis suggests the participation rate for these students was four percentage points higher than the results of GCSEs in 2009 would have predicted.
Also, the non-continuation rate for full-time students has improved from a rate of 14% in 2003-04 to 10% in 2013-14.
The number of disabled students going to university has increased from just over 16,700 in 2003-04 to just over 51,300 in 2012-13.
Hefce also wants to find out why some ethnic minority groups are more likely to underachieve in their degrees.
Its report - Delivering opportunities for students and maximising their success - said: "There is isolated work across institutions to address differential outcomes, but it is fragmented and not well evidenced.
"There is a need for a joined up sector wide response to secure a step change that will maximise outcomes for all students."
Hefce chief executive Prof Madeleine Atkins said: "Universities and colleges have already made significant progress in terms of widening access and improving retention for students whose talents and skills risk being overlooked.
"To build on this success to date, we should now focus on establishing which interventions are working most effectively to educate the graduates the country needs.
"Hefce will work with universities and colleges to implement methods to evaluate what kinds of activities work best across the whole student lifecycle and into employment."
Fair Access to Higher Education director Prof Les Ebdon said: "Hefce is right to point out that more needs to be done to better understand the evidence of what works to improve outcomes for groups of students who don't do as well as their peers.
"Most importantly, universities and colleges need to translate their significant commitment in this area into improved outcomes.
"In line with the national strategy for access and student success, we will continue to work closely with Hefce and the whole sector to improve the evidence around fair access and support effective practice by universities and colleges.
"This should help ensure that all students - irrespective of background - can truly fulfil their potential."
The report follows an announcement from Hefce on Wednesday that it was cutting university funding grants for the academic years 2014-15 and 2015-16.
This is in the wake of the government's decision to reduce spending by £150m.