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.

Purpose

To determine if the relationship between primary care physician density and odds of late-stage cancer is 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: the 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 from Ohio Department of Health. Multilevel logistic regression models estimated odds ratios of latestage 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.