As the health care industry becomes more and more concentrated, some small private practices find it difficult to compete with big health care systems. So, instead, they’re joining them. As of January, hospitals owned 26% of physician practices nationwide, up from 14% a decade ago. An additional 27% of practices were owned by a corporation, such as a health insurer or a private equity firm, leaving fewer than half of physician practices under independent ownership. But, to the patient, does it really matter whether practices are owned independently or by a health system?