There's a lot of chatter about how public policy can influence doctors' decisions about which new patients to see and which to turn away. One big question: Does the squeeze on Medicare that has limited the program's pay increases to doctors lead them to see fewer of those patients? Some researchers decided to look at recent data for clues. And they found a slight drop — a little less than 3 percent in the proportion of doctors taking new Medicare patients between 2005 and 2008. But that drop, which still left 93 percent of docs taking new Medicare patients, wasn't much compared with the hit for patients with typical private insurance. For those people, there was a 5.5 percentage point drop, leaving about 88 percent of physicians who would add them as new patients. The greater decline in doctors accepting private insurance was "unexpected," the researchers write in the latest issue of Archives of Internal Medicine, where the findings appear. What's going on? I asked lead author Dr. Tara Bishop, an internist and assistant professor of public health at Weill Cornell Medical College in New York. She said there are a couple of possible reasons. Some doctors may be bucking the administrative hassles of private insurance, she said. Medicare may not always pay top dollar, but it's pretty reliable. And, she said, Medicare is still the largest payer, so it's hard for doctors not to accept those patients. For her part, Bishop sees patients with all kinds of insurance. But she said the findings are worrisome. "If these trends continue we may have problems getting care to patients in the ambulatory setting," she said. "It's possible patients might have health insurance but not be able to see a doctor."