WASHINGTON — In-store medical clinics such as those at Walmart, having established a beachhead with relatively healthy patients looking for convenient, low-cost care for simple problems, are going after a bigger prize: the millions of Americans with costly illnesses such as diabetes and heart disease. “It’s sad that the existing health care establishment has not figured out a way to make primary care affordable and accessible,” said Jerry Avorn, HMS professor of medicine at Brigham and Women’s Hospital. “We should not be surprised if someone outside of our world comes in and does it for us.”
