The ARCHIVES OF INTERNAL MEDICINE (ISSN 0003-9926) is published twice a month, except for combined issues in August and December, by the American Medical Association, 515 N State St, Chicago, IL 60610-0946, and is an official publication of the Association. The ARCHIVES OF INTERNAL MEDICINE reaches more than 98 400 readers in over 82 countries each month. Periodicals postage paid at Chicago, Ill, and at additional mailing offices. GST registration number 12622 5556 RT. Canada Post International Publications Mail (Canadian Distribution) Sales Agreement No. 318655. POSTMASTER, send all address changes to Archives of Internal Medicine, c/o the AMA Unified Service Center, American Medical Association, 515 N State St, Chicago, IL 60610. Printed in the USA.