Posted in | Imaging | Medical Optics

Scientists Analyze Data on Utilization Rates of Virtual and Optical Colonoscopies

Rates of colorectal cancer screening vary by race and ethnicity as well as method, according to data being presented at Digestive Disease Week® (DDW®) 2010.

Scientists examine data on minority and older populations as well as utilization rates of virtual and optical colonoscopies to better understand adherence to recommended screening guidelines. DDW is the largest international gathering of physicians and researchers in the field of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.

Impact of a CT Colonography Colorectal Cancer Screening Program on Optical Colonoscopy: 5 Year Data

Researchers at the University of Wisconsin found that increased accessibility of virtual colonoscopies, colonoscopies completed via CT scan, did not decrease the use of traditional optical colonoscopies for colorectal cancer (CRC) screenings.

Virtual colonoscopy, which was introduced nearly 10 years ago as a non-invasive alternative to colorectal cancer screenings, allows physicians to examine the colon and surrounding areas for polyps and other irregularities. However, virtual colonoscopies only allow physicians to spot certain polyps, creating a need for additional tests if polyps are found. Traditional colonoscopies remain the gold standard test for CRC screenings since doctors are able to identify and remove polyps in one test.

"Previous theoretical studies showed that once virtual colonoscopies became accepted as a national screen test, regular colonoscopies would be reduced by 25 percent," said Patrick Pfau, MD, associate professor and director of clinical gastroenterology at the University of Wisconsin School of Medicine and Public Health. "But since our virtual colonoscopy program began in 2004, we have seen no change. In fact, we have seen an increase in the number of traditional colonoscopies."

In 2004, the University of Wisconsin became the first institution in the U.S. to accept third-party payor coverage for virtual colonoscopy exams. To examine the effects of the virtual colonoscopy program on rates of optical colonoscopies, researchers looked at total CRC screenings from 2003 to 2008 in patients aged 50 to 75. Over this five-year period, the total number of CRC screening exams (virtual + optical colonoscopies) increased 53 percent from 555 screenings per quarter in 2003 to 1,187 in 2008. Virtual colonoscopies peaked at 307 exams performed in the third quarter of 2005, declining to 203 exams performed in the last quarter of 2008.

During this same time, optical colonoscopy exams increased significantly from 555 exams per quarter in 2003 to 995 exams per quarter performed in 2008. In 2009, five years after initiation of the virtual colonoscopy screening program, an average of 1,255 quarterly screening exams were performed with 86.6 percent of the patients screened with optical colonoscopies and 8.5 percent screened with virtual colonoscopies.

Dr. Pfau will present these data on Tuesday, May 4 at 10:30 a.m. CT in 260-262, Ernest N. Morial Convention Center.

Method of Recommendation for Colorectal Cancer Screening Strategies Impacts Adherence

It is assumed that better outcomes from colorectal cancer (CRC) screening are achieved by recommending colonoscopy as the preferred screening test. However, this method of recommendation may adversely impact adherence to screening in diverse populations, according to a new study from researchers at the University of California, San Francisco (UCSF) who found that recommending colonoscopy resulted in lower adherence compared with recommendations for fecal occult blood test (FOBT), or a choice of the two procedures.

The findings are important because current screening guidelines stress colonoscopy as the preferred screening strategy.

Researchers conducted a study comparing single and multiple recommendations for CRC screening in a racially diverse population. About 1,000 patients at average risk for CRC were randomly assigned to receive a recommendation by their primary care provider for FOBT, colonoscopy or a choice of the two. Patients completed a survey of recommended tests as well as those they actually adhered to in the following year, and complete follow-up was achieved in 99 percent of the patients.

"The unique aspect of our study was the ability to identify differences in adherence to screening based on the method of recommendation, and whether these varied between different racial and ethnic groups," said John M. Inadomi, MD, professor of medicine at UCSF and chief of clinical gastroenterology, San Francisco General Hospital.

Results showed that overall, 65.1 percent of patients adhered to screening, but there were differences among the groups: 38 percent of patients recommended for colonoscopy alone underwent this screening, 67 percent recommended for FOBT alone returned the test, and 70 percent who were given a choice between colonoscopy or FOBT adhered to either screening strategy. Even when accounting for adherence to FOBT among patients who were recommended colonoscopy only, the combined adherence to either test (58 percent) remained significantly lower compared with the groups who were recommended FOBT alone or provided a choice.

In order to reduce health-care system barriers to screening, researchers made sure that the colonoscopy could be done within two weeks of being scheduled, that the cost of the procedure was not borne by the patient, if patients needed a ride to their procedure they were provided with one, and patients were given instructions for the preparation and the procedure in the preferred language of the patient. Despite these interventions, adherence to colonoscopy remained low.

"If we follow our current guidelines regarding the promotion of colonoscopy as the preferred strategy for colonoscopy screening, in ethnically diverse populations we could be adversely impacting adherence to colon cancer screening," Dr. Inadomi said.

Still, Dr. Inadomi cautioned that these findings cannot be generalized to all populations that are not, as this one was, ethnically and racially diverse and in a safety net setting, with patients who tend to have lower socioeconomic status, education and income. He also cautioned that researchers looked only at the first episode of screening and that further research is being conducted to determine whether these findings are consistent when adherence to programmatic screening, as is required for FOBT, is evaluated.

Dr. Inadomi will present these data on Sunday, May 2 at 10:30 a.m. CT in 288-290, Ernest N. Morial Convention Center.


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