US Doctors Need Records at time of Patient Visit?

"Once in the health-care system, 32% of U.S. patients suffered medical mistakes, the highest rate of the seven nations. That could be because the U.S. ranked last when it came to their doctors having access to their medical records at the time of an office visit."

Link: Business Week Web Reference

Personally, I wonder where the medical mistakes data is coming from and whether it was obtained from all patients or a sampling; it would be nice if Business Week made that clear. However, I have personally seen a huge effort to get physician's offices ramping up to get their patient's data integrated with local hospital health information systems. So ... maybe things are looking up for US?