BACKGROUND: Our research group advanced a health insurance theory to explain Canada's @entity5 care advantages over America. The late Barbara Starfield theorized that Canada's greater primary care-orientation also plays a critically protective role. We tested the resultant Starfield-Gorey theory by examining the effects of poverty, health insurance and physician supplies, primary care and specialists, on @entity694 care in Ontario and @entity7452 . METHODS: We analyzed registry data for @entity1 with non-metastasized @entity694 from Ontario (n   =   2,060) and @entity7452 (n   =   4,574) diagnosed between 1996 and 2000 and followed to 2010. We obtained census tract-based socioeconomic data from population censuses and data on county-level physician supplies from national repositories: primary care physicians, gastroenterologists and other specialists. High poverty neighborhoods were oversampled and the criterion was 10  year survival. Hypotheses were explored with standardized rate ratios (RR) and tested with logistic regression models. RESULTS: Significant inverse associations of poverty (RR   =   0.79) and inadequate health insurance (RR   =   0.80) with survival were observed in the @entity7452 , while they were non-significant or non-existent in Ontario. The direct associations of primary care physician (RRs of 1.32 versus 1.11) and gastroenterologist (RRs of 1.56 versus 1.15) supplies with survival were both stronger in Ontario than @entity7452 . The supply of primary care physicians took precedence. Probably mediated through the initial course of treatment, it largely explained the Canadian advantage. CONCLUSIONS: Poverty and health insurance were more predictive in the USA, community physician supplies more so in Canada. Canada's primary care protections were greatest among the most socioeconomically vulnerable. The protective effects of Canadian health care prior to enactment of the Affordable Care Act (ACA) clearly suggested the following. Notwithstanding the importance of insuring all, strengthening America's system of primary care will probably be the best way to ensure that the ACA's full benefits are realized. Finally, Canada's strong primary care system ought to be maintained.

XXXX care and survival: income and insurance are more predictive in the USA, community primary care physician supply more so in Canada.

@entity5 :: ('MESH:D009369', 'Disease') :: ['cancer'] @entity1 :: ('9606', 'Species') :: ['people'] @entity7452 :: ('MESH:D004670', 'Disease') :: ['California'] @entity694 :: ('MESH:D003110', 'Disease') :: ['colon cancer']
@entity694 :: (MESH:D003110,Disease) :: ['Colon cancer']
