[1] NEW ENGLAND MED CTR HOSP, DEPT MED, BOSTON, MA 02111 USA
[2] NEW ENGLAND MED CTR HOSP, CLIN DECISION MAKING GRP, BOSTON, MA 02111 USA
[3] MIT, COMP SCI LAB, CLIN DECISION MAKING GRP, CAMBRIDGE, MA 02139 USA
[4] TUFTS UNIV, SCH MED, BOSTON, MA 02111 USA