Abstract B80: Use of geographic information systems to visualize the screening colonoscopy referral network of the University of Chicago Medical Center
Authors: Naylor Keith B. , Kassim Olufemi , Kim Karen E. 
Published: May 2016

Background: In Illinois for the year 2015, colorectal cancer (CRC) is projected to cause 2,090 deaths, making it the leading cause of non-tobacco related cancer mortality. African American Illinois residents have an approximately 7% greater incidence and a 30% higher mortality rate when compared to white residents. Guideline consistent routine screening is known to reduce death due to CRC. Screening colonoscopy is the most commonly performed CRC screening test. However, African Americans are known to have low rates of screening colonoscopy and diagnostic colonoscopy completion compared to whites.

Chicago's South Side includes 34 of the city's 77 recognized community areas and is home to a combined population of more than 800,000 residents, of whom greater than 75% are African American. The contiguous communities that make up the South Side cover approximately 60% of Chicago's land area. There are 41 facilities throughout Chicago that perform outpatient screening colonoscopy, of with 13 (32%) are located on Chicago's South Side. The University of Chicago Medical Center (UCMC) is the largest healthcare provider on the South Side and represents 30% of the local capacity for screening colonoscopy services.

Objectives: The objectives of this study were to use geographic information systems (GIS) and geospatial analysis to explore the distribution of patients who completed a screening colonoscopy at the UCMC during calendar year 2014 and to visualize the associated physician referral network.

Methods: A retrospective chart review was performed for all individuals who completed a screening colonoscopy during calendar year 2014 at UCMC. Screening colonoscopies were identified through CPT codes: G0105 (Colorectal cancer screening; colonoscopy on individual at high risk) and G0121 (Colorectal cancer screening; colonoscopy on individual no meeting criteria for high risk). Mapping and spatial analysis were performed using ArcMap version 10.1. Descriptive statistics were performed using STATA 13.1.

Results: During calendar year 2014, 1632 outpatient screening colonoscopies were completed on 1592 patients (mean age, 59 years; 36% male; 49% AA, 29% white). Of the 1,632 screening colonoscopy procedures, 1,017 (62%) were completed on patients with ZIP codes located within Chicago's South Side (mean age, 59 years; 33% male; 63%AA, 17% white). Of the 1,017 colonoscopies performed on South Side residents, 102 (10%) were completed as a result of a referral from an external non-UCMC affiliated physician and 915 (90%) were completed as a result of a referral from a UCMC affiliated physician.

Conclusions: The majority of patients who completed a screening colonoscopy at UCMC during calendar year 2014 were residents of the South Side. However, only 10% of the screening colonoscopies completed on South Side residents were related to referrals obtained from non-UCMC affiliated physicians. These results may indicate the presence of a weak referral network between the largest local healthcare provider, UCMC, and local South Side physicians for screening colonoscopy.

Citation Format: Keith B. Naylor, Olufemi Kassim, Karen E. Kim. Use of geographic information systems to visualize the screening colonoscopy referral network of the University of Chicago Medical Center. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr B80.