Less than half of the women in Ontario with abnormal Pap smears receive the recommended followup care, researchers say.

The findings were released Thursday by the Institute for Clinical Evaluation Sciences and were based on tracking all women who used OHIP services from 2004 to 2005.

The joint team of researchers from the institute and St. Michael's Hospital in Toronto reviewed screening rates for cervical, breast and colorectal cancers.

"I was quite surprised with the low rates of followup of the abnormal Paps," said the study's lead researcher, Dr. Arlene Bierman of St. Michael's Hospital. "But we did go to the literature and this is a universal problem in health systems."

Pap tests are used to detect abnormal cells in the cervix. In the study, 44 per cent of abnormal Pap results were followed up, as were 35 per cent of inadequate Pap tests.

Normally after an abnormal Pap finding, the test would either be repeated or doctors would perform a colposcopy — a procedure that examines a woman's cervix and vagina.

The followup care is important since those with a low-grade abnormality are usually at greatest risk of eventually developing cervical cancer, the team said.

Screening rates varied by income

Researchers also looked at how screening rates differed among women depending on income.

The results showed 61 per cent of women living in the lowest income neighbourhoods had at least one Pap test in the last three years compared with 75 per cent for those living in the wealthiest neighbourhoods, after standardizing for age.

Overall in Ontario, 56 per cent of lower-income women and 64 per cent of higher-income women received a mammogram in the last two years.

It's important to continue to reach underscreened populations by improving awareness of screening and access to the tests and followup services, said Dr. George Pasut, vice-president, prevention and screening for Cancer Care Ontario.

Results of the POWER study (Project for an Ontario Women’s Health Evidence-Based Report) are contained in a report entitled Cancer.

The study was funded by Echo: Improving Women's Health in Ontario, an agency of the Ontario Ministry of Health and Long-Term Care.