University of California San Francisco
Helen Diller Family Comprehensive Cancer Center

Many Safety Net Patients Don’t Complete Colonoscopy after Abnormal Stool-Based Colorectal Screening Test

UCSF Study Recommends Multilevel Intervention to Increase Participation

By Scott Maier | | December 13, 2016

Many Safety Net Patients Don’t Complete Colonoscopy after Abnormal Stool-Based Colorectal Screening Test

Genomic amplification of the oncogene c-myc (yellow) in a mouse model of human colorectal cancer. Photo courtesy of the NCI Center for Cancer Research.

Nearly half of the patients in a safety net health system who had an abnormal stool-based screening test for colorectal cancer failed to receive the recommended colonoscopy within a year, despite the benefits of an integrated health care system with access to colonoscopy and shared electronic health records, according to researchers at UC San Francisco. They suggest a multilevel intervention approach to increase participation.

The study appears online Dec. 13, 2016, in The American Journal of Gastroenterology.

“Much has been published about non-invasive screening tests for colon cancer, but there are few reports on how patients with abnormal results do in follow up,” said lead author Rachel Issaka, MD, gastroenterology fellow at UCSF and the Priscilla Chan and Mark Zuckerberg San Francisco General Hospital and Trauma Center (ZSFG).

Colorectal cancer is the second leading cause of U.S. cancer deaths. Even with evidence that screening is effective in reducing mortality, it remains underutilized in the general population, especially among racial/ethnic minorities and low-income populations.

In safety net health care settings, which provide significant care to low-income, uninsured and vulnerable populations, a stool-based screening test called the fecal immunochemical test (FIT) is often promoted because of patient preference and limited colonoscopy resources. FIT, recommended by the American Cancer Society for screening, looks for microscopic levels of blood in the stool. As the risk of colorectal cancer is more than 10 times higher after an abnormal stool test, a subsequent diagnostic colonoscopy is strongly recommended.

Study Utilizes the San Francisco Health Network

In The American Journal of Gastroenterology study, Issaka and her colleagues analyzed 2,238 patients ages 50-75 who had received a positive FIT result between April 2012 and February 2015 in the San Francisco Health Network (SFHN).

SFHN includes 11 community- and hospital-based primary care clinics and ZSFG. These clinics share an integrated electronic health record, clinical laboratory and gastroenterology referral unit. The FIT kit is used at home and mailed to the ZSFG laboratory for analysis, with results usually routed to the primary care provider.

SFHN uses an electronic referral platform for all gastroenterology clinic referrals, which a staff gastroenterologist typically evaluates within 72 hours. Patients either attend a clinic appointment or group colonoscopy class, as appropriate, then are consented and scheduled for colonoscopy.

Of the 2,238 total patients analyzed, 1,245 (56 percent) patients completed colonoscopy within a year at an average time of six months (184 days). Women were more likely than men, and married patients more likely than single, separated or divorced patients to complete the procedure. Asian patients had the highest follow-up rate, and non-English speakers were more likely to follow up than English speakers.

Thirteen (13) percent were never referred to the ZSFG gastroenterology group for follow up. Within this group, 49 percent lacked documentation addressing their abnormal result or counseling on the increased risk of prevalent colorectal cancer. Of those patients referred and scheduled, 25 percent missed their appointment, with 62 percent lacking follow-up documentation or counseling. Further, patients with comorbid conditions and illicit substance use were less likely to be referred or make their appointments.

“Despite access to colonoscopy and a shared electronic health record system, colonoscopy completion after an abnormal FIT is inadequate,” said senior author Ma Somsouk, MD, MAS, UCSF Health gastroenterologist and the Dean M. Craig Endowed Chair in Gastrointestinal Medicine. “This issue is attributable to an absence of clear documentation and systematic workflow within both primary care and gastroenterology specialty care. And, at times, patients are too ill to get the benefit of cancer screening but are screened anyways.”