The effect of provider density on lung cancer survival among blacks and whites in the United States.

INTRODUCTION: Lung cancer mortality rates may vary with access to specialty providers and local resources. We sought to examine the effect of access to care, using density of lung cancer care providers, on lung cancer mortality among blacks and whites in the United States.
METHODS: We examined U.S. county-level data for age-adjusted lung cancer mortality rates from 2003 to 2007. Our primary independent variable was per capita number of thoracic oncologic providers, adjusting for county-level smoking rates, socioeconomic status, and other geographic factors. Data were obtained from 2009 Area Resource File, National Center for Health Statistics, and the County Health Rankings Project.
RESULTS: Providers of lung cancer care were unevenly distributed among the U.S. counties. For example, 41.4% of the U.S. population reside in counties with less than four thoracic surgeons per 100,000 people, 23.4% in counties with 4 to 15 surgeons per 100,000 people, and 35.3% in counties with more than 15 surgeons per 100,000 people. Geographically, 4.3% of whites compared with 11.2% of blacks lived in high lung cancer mortality zones. Lung cancer mortality did not vary by density of thoracic surgeons or oncology services; however, higher primary care provider density was associated with lung cancer mortality reduction of 4.1 per 100,000 for whites.
CONCLUSION: Variation in provider density for thoracic oncology in the United States was not associated with a difference in lung cancer mortality. Lower mortality associated with higher primary care provider density suggests that equitable access to primary care may lead to reduced cancer disparities.