NOW THAT OBAMACARE is in its death throes, supporters are backpedaling furiously.

For much of the past year, President Obama lavished praise on a few select hospitals like the Mayo Clinic for delivering high-quality care at low costs, but a pointed analysis published Wednesday in an influential medical journal suggests that the president’s praise may be unwarranted.

Mr. Obama received his information about the hospitals from a widely cited analysis called the Dartmouth Atlas of Health Care, produced by the Dartmouth Institute for Health Policy and Clinical Practice. An article in The New Yorker magazine last year written by Dr. Atul Gawande that used the Dartmouth Atlas as its organizing principle became required reading in the White House last year.

But an analysis written in The New England Journal of Medicine by Dr. Peter B. Bach, a physician and epidemiologist at Memorial Sloan-Kettering Cancer Center in Manhattan, suggests that much of the Dartmouth Atlas is flawed and that it should not be used to compare the relative efficiency of hospitals.

Even the authors of the Dartmouth Atlas are backing away. Dr. Elliott Fisher, director of the Center for Health Policy Research said that “he and his colleagues should not be held responsible for the misinterpretation of their data.”