2009 HSR&D National Meeting Abstract
3007 — Effect of Access to CBOCs on Colorectal Cancer Screening Adherence among Non-Elderly Average-Risk Veterans
Bian J (Atlanta VAMC), Gillespie TW
(Atlanta VAMC), Lipscomb J
Little is known about the performance of VA community-based outpatient clinics (CBOCs). This study examines the impact of access to CBOCs on adherence to colorectal cancer (CRC) screening among non-elderly veterans regularly using the VHA health care system.
We use 1997-2007 VA Medical SAS and Fee Basis data to construct a balanced veteran-level longitudinal dataset from 2001-2007. The sample includes veterans who were age 50-58 in 2001 and who had at least two primary care visits in each year from 2001-2007. Linear probability models with veteran and year fixed-effects are used for estimation. The unit of analysis is a veteran-year. The dependent variable is the status of CRC screening adherence in each of the 7 years. The key explanatory variable is access to CBOCs, coded as 1 if a veteran had at least one primary-care-related CBOC visit in a given year, or 0 otherwise. Other key time-varying covariates include the number of CBOCs and veteran volume at the VA medical center level. Standard errors are adjusted via Huber clustered standard errors correction at the veteran level.
The sample includes 1,595,447 veteran-years, consisting of 227,921 veterans. The proportion adhering to CRC screening increased from 32.1% in 2001 to 43.3% in 2005, but declined to 38.0% in 2007. The proportion accessing CBOCs increased from 51.2% to 56.6% during the 7-year period. Our regression analysis shows that access to CBOCs was associated with a 2.3-percentage-point increase in the likelihood of CRC screening adherence (P < 0.001). Furthermore, increased volume of veterans who used VA health services was associated with a decrease in the likelihood of CRC screening adherence.
Our study suggests that although access to CBOCs may improve the quality of CRC screening adherence, increasing demand for VA health services may hinder the effort to continuously improve the quality of CRC screening adherence.
Our findings suggest that the VA needs to continue its effort on improving the geographical availability of its services to millions of veterans. Furthermore, additional VA resources are needed to meet the increasing demand for heath care services as more veterans seek care from the VA in the future.