More than 10 percent of students who transfer from community colleges to four-year institutions such as Boston University lose a majority of their credits during the switch, according to a study released Wednesday.

“The percentage of credits you get transferred has a not insubstantial effect on one’s probability of completing a bachelors degree,” said City University of New York Research Analyst David Monaghan, who co-authored the study.

The study, conducted by Monaghan and CUNY Professor Paul Attewell, found students who retained most or all of their credits upon transferring to a four-year university were 2.5 times more likely to earn a bachelor’s degree than those who transferred fewer than half of their credits.

“A lot of these are lower income students, students who struggle with a lot to get through school in the first place, students who have to work full time while going to school, maybe students who are raising children while going to school, and so squeezing out each set of three credits is really an accomplishment,” Monaghan said.

Monaghan said the transfer process often frustrated students who transferred from community colleges to four-year institutions.

“If you’re being put back essentially a semester or two semesters in terms of the number of credits you think you have when you transfer, that can be very disheartening,” he said.

BU spokesman Colin Riley said the university aims to accept as many credits as possible from students who transfer from community colleges.

“We’re not going to separate a community college student from any other student who’s applying as a transfer student,” he said.

Riley said fewer than 20 students who attend BU have transferred from community colleges.

Monaghan said many students who transfer from community colleges have credits that carry over to a four-year institution, though they may not fulfill identical credit requirements.

“Where this is a course that someone is trying to transfer that we do not have an exact equivalent [for], we may give elective credit for it,” Riley said.

Riley said students who intended on transferring to BU from a community college should consult the university before transferring.

“It’s a very simple thing to call up one of the four-year colleges you’re interested in and say, ‘Could you give me an idea of the transferability of these three or four courses that I’ve taken or that I’m considering to register for,’” he said.

Several students said transferring from a community college to a four-year institution like BU would be a difficult process.

“The biggest challenge is the stigma that goes along with a community college,” said Samuel Blank, a senior in the College of Arts and Sciences and the School of Management. “People look at you differently. They say, ‘Well you must not be very intelligent. Why did you go to community college as opposed to BU if you could get into BU?’”

Andrew Colletta, a College of Engineering freshman, said that institutions such as BU could be justified in refusing to accept credits from a community college.

“There’s a reason why we’re paying so much to go to BU,” he said. “We’re here to learn from the best and get a real hands on experience, whereas at a community college you’re not going to get into those research labs like we will, tour around Boston like we will, going into hospitals and such.”

Caroline Wittschen, a sophomore in CAS who worked in the admissions office transfer department, said students who transfer from community colleges often struggle with financial issues.

“I read so many emails and I see firsthand how much passion they have, how much they want to come to BU and then they can’t afford it,” she said. “It’s almost heartbreaking. That is a really difficult thing to overcome transferring to BU, especially because we just had another increase with our tuition and housing.”