The report found that companies retain 72% of graduates and 75% of non-graduates after three years, and 57% of graduates and 69% of non-graduates after five years.
A quarter (25%) of companies reported it is more difficult to retain women and slightly less than a fifth (17%) reported that it is harder to retain people from a Black, Asian or Minority Ethnic (BAME) background.
Tristram Hooley, ISE’s chief research officer, told HR magazine: "These findings give employers some useful insights on how graduates and non-graduates progress through and beyond training and development programmes.”
In the survey, companies said retention issues were influenced by the image and culture of their sector, a lack of role models, line managers failing to adapt their style to the needs of different groups, and the staff not believing they can progress within the industry.
The majority (79%) of companies said they continue to provide ongoing support for hires after the initial graduate programme or apprenticeship has finished and almost all (97%) provide further support for hires that are experiencing mental health issues.
Most companies (56%) also said they try to identify high performing staff during initial training and provide such staff with additional support for their progression.
The average company reported paying its graduates £40,000 per year and its non-graduates £27,500 per annum three years after they are first employed.
ISE chief executive Stephen Isherwood added that despite investment and resources spent on tackling the gender gap, women are still underrepresented across the graduate employment market.
“We know that female students are less likely to apply for graduate roles and are therefore underrepresented on early careers programmes. This now tells us that they are also less likely to stay in an organisation. To tackle disparity, we must not only look at who gets in, but who gets on,” said Isherwood.
The report is based on 133 responses from ISE members responsible for employing over 20,000 entry-level staff every year.