N Engl J Med. 2011 Jul 28;365(4):e7. doi: 10.1056/NEJMp1107671. Epub 2011 Jul 13.
The New England journal of medicine
Katherine Baicker, Michael E Chernew
PMID: 21751901 DOI: 10.1056/NEJMp1107671
[No abstract available.]