Assessing Hereditary Colorectal Cancer Referral Patterns to a Tertiary Care Center: A Novel Approach Using Geographic Information System Mapping.

BACKGROUND: Patients and their family members with hereditary colorectal cancer require longitudinal follow-up that is best achieved through a dedicated program with a registry. However, referrals for these conditions remain poor. Geographic information systems technology is a novel method to evaluate geographic variation in multiple realms but is being used more in health care. OBJECTIVE: The purpose of this study was to evaluate referral patterns with geographic information systems technology to better target efforts for improving overall referrals. We hypothesized that marked variation would exist as to the geospatial locations of referrals and that gastroenterologists would be the dominant referral source. DESIGN: This was a retrospective cross-sectional study. SETTINGS: The study was conducted at Vanderbilt University Medical Center. PATIENTS: The hereditary colorectal cancer registry was queried from June 2007 to August 2016 for demographics, distance to center, genetic mutations, and the specialty of the referring providers. Geospatial data on both patient and referring specialist were collected. MAIN OUTCOME MEASURES: We analyzed patient and referral data with geographic information systems technology to look for gaps and patterns. RESULTS: A total of 676 patients were entered into the registry during this period. Fifty-six percent were women, and the median age was 50 years (interquartile range, 42-60 y). The median distance from the center was 60 miles (interquartile range, 22-120 miles), and 31% carried an identified germline mutation. Gastroenterology represented the overall largest source of referrals and, when broken down by syndrome, they represented the top referral specialty for familial adenomatous polyposis. Surgeons were the largest referral source for Lynch syndrome. LIMITATIONS: The study was limited by covariates in the database. CONCLUSIONS: Our hereditary colorectal cancer registry serves a large geographic area, with the largest group of referrals coming from gastroenterologists. Performing this analysis with geographic information systems technology mapping allowed us to identify clustering of patients and providers throughout the region as well as gaps. This information will help to target outreach and distribution of educational materials for providers and their patients to increase registry enrollment. See Video Abstract at .