title: Primary care physician supply, insurance type, and late-stage cancer diagnosis.
abstract: BACKGROUND
  Understanding the joint effects of insurance type and primary care physician density on stage at diagnosis is essential to elucidating the healthcare access and late-stage cancer relationship.
  
  
  OBJECTIVE
  To determine if the relationship between primary care physician density and odds of late-stage cancer are modified by insurance type at diagnosis.
  
  
  METHODS
  Case patients were Ohio adults diagnosed between 1996 and 2008 with cancer of one of the following sites: female breast, cervix, colon/rectum, lung/bronchus, melanoma of the skin, oral cavity and pharynx, or prostate (N=376,425). County-level physician density was obtained from the Ohio Department of Health. Multilevel logistic regression models estimated odds ratios of late-stage cancer diagnosis associated with increases in primary care physician density by insurance type. Analyses were conducted in 2014.
  
  
  RESULTS
  Decreases in late-stage diagnosis of cancers of the breast, prostate, melanoma of the skin, oral cavity and pharynx, or lung/bronchus associated with increases in primary care physician density were strongest among those with private insurance, whereas those with Medicare (prostate, oral cavity and pharynx, lung/bronchus), Medicaid (lung/bronchus), uninsured (prostate), and other/unknown (prostate, oral cavity and pharynx, lung/bronchus) did not benefit as greatly, or experienced significant increases in late-stage cancer diagnosis (other/unknown [female breast], Medicaid [melanoma of the skin], and uninsured [colon/rectum]).
  
  
  CONCLUSIONS
  As primary care physician density increases, those with private insurance consistently benefit the most in terms of late-stage cancer diagnosis, whereas those with several other insurance types experience flatter decreases or significantly higher odds of late-stage cancer diagnosis.
authors.affiliation: Department of Health Services, School of Public Health, The University of Washington, Seattle, Washington. Electronic address: plascak@uw.edu.
authors.forename: Jesse J
authors.initials: JJ
authors.lastname: Plascak
authors.affiliation: James Cancer Hospital and Solove Research Institute.
authors.forename: James L
authors.initials: JL
authors.lastname: Fisher
authors.affiliation: James Cancer Hospital and Solove Research Institute; Division of Cancer Control and Prevention, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio.
authors.forename: Electra D
authors.initials: ED
authors.lastname: Paskett
mesh_terms: D057210:Delayed Diagnosis; D005260:Female; D006801:Humans; D007348:Insurance, Health / Q000706:statistics & numerical data; D008297:Male; D008484:Medicaid / Q000706:statistics & numerical data; D017057:Medically Uninsured / Q000706:statistics & numerical data; D006278:Medicare / Q000706:statistics & numerical data; D009369:Neoplasms / Q000175:diagnosis*; D009820:Ohio / Q000453:epidemiology; D058007:Physicians, Primary Care / Q000600:supply & distribution*; D017149:Private Sector; D014481:United States / Q000453:epidemiology