The true causes of income-related health disparities are not known. In 3407 Canadian patients who were hospitalized for acute
myocardial infarction, high income was associated with a lower 2-year mortality rate (crude hazard ratio, 0.45 [95% CI, 0.35
to 0.57]; P < 0.001). However, adjusting for income-related differences in age and the prevalence of preexisting cardiovascular events
or risk factors substantially reduced the effect of high income (adjusted hazard ratio, 0.77 [CI, 0.54 to 1.10]; P = 0.150).