Urine testing may be as effective as the smear test at preventing cervical cancer and could significantly increase participation rates for screening, a study has found.

The research, published in the journal BMJ Open, found that urine testing was just as good as the cervical smear at picking up high-risk human papillomavirus (HPV), the virus that causes cervical cancer.

Researchers from the University of Manchester in the UK said a urine test could help increase the numbers of women who are screened for cervical cancer.

Urine testing could have a role in the developing world, where cervical cancer is up to 15 times more common and smear testing largely non-existent.

Around one in 20 women show abnormal changes which might go on to become cancer and are referred for colposcopy, where the cervix is examined under magnification, allowing abnormal areas to be seen, sampled and treated, before they ever cause cancer, researchers said.

According to the team, cervical smear samples, self-collected vaginal samples and urine samples are all effective at picking up high risk HPV infection.

Cervical cancer is most common in women aged 30 to 35 years. However, the precancerous stage is detectable in the 5-10 years before this, when up to a third of women fail to attend for their smear test.

"We're really very excited by this study, which we think has the potential to significantly increase participation rates for cervical cancer screening in a key demographic group," said Emma Crosbie, who led the study.

"Many younger women avoid the National Health Service (NHS) cervical cancer screening programme because they find it embarrassing or uncomfortable, particularly if they have gynaecological conditions like endometriosis," Crosbie said in a statement.

Of the 100 or so types of HPV, some are linked to cervical cancer, and some are linked to other conditions, like genital warts.

Most cervical cancers are caused by high-risk types HPV-16 and HPV-18.

As many as 104 women attending the colposcopy clinic at St Mary's Hospital in the UK participated in the study and were screened using two brands of HPV testing kits.

Around two-thirds of the women tested positive for any high-risk HPV type, and a third for HPV-16 or HPV-18.

From the total, eighteen women had pre-cancerous changes to the cervix that needed treatment.

With the Roche HPV testing kit, urine, vaginal self samples and cervical smears picked up 15 of these.

With the Abbott HPV testing kit, urine picked up 15 of these and vaginal self samples and cervical smears picked up 16.

"These results provide exciting proof of principle that urine HPV testing can pick up cervical pre-cancer cells, but we need to trial it on a greater number of women before it can be used in the NHS. We hope that is going to happen soon," Crosbie said.