there is a great deal of research into inequalities in health care. in some cases, these inequalities are caused by income disparities that result in lack of health insurance and other barriers to receiving services. in other cases, inequalities in health care reflect a systemic bias in the way medical procedures and treatments are prescribed for different ethnic groups. raj bhopal writes that the history of racism in science and medicine shows that people and institutions behave according to the ethos of their times. nancy krieger wrote that racism underlies unexplained inequities in health care, including treatment for heart disease, kidney failure, bladder cancer, and pneumonia. raj bhopal writes that these inequalities have been documented in numerous studies. the consistent and repeated findings were that black americans received less health care than white americans, particularly when the care involved expensive new technology. one recent study has found that when minority and white patients use the same hospital, they are given the same standard of care.