While there was some correlation between board certification and quality, it was very small, Reid said.
"Few characteristics were consistently associated with high quality care and those we did find were so small in magnitude that they are not significant in a practical sense," said study co-author Ateev Mehrotra, an assistant professor at the University of Pittsburgh School of Medicine and a RAND researcher.
Overall, the physicians studied provided about 63% of the recommended care, according to the RAND process measure tools. Average performance varied by condition, ranging from 31% for cataract care to 68% for care of congestive heart failure.
Reid acknowledges that the study results might be different if done today, when more practitioners have access to electronic medical records and decision support tools on the Internet. More health plans are requiring checklists for a variety of process measures in exchange for better pay.
And, she says, the RAND process measure tool is only one type of tool, and does not measure actual outcomes, or mortality, or whether the patient actually recovers from the illness that prompted the trip to the doctor.