From *RAND, Santa Monica, CA, the †Department of Epidemiology, University of California, Los Angeles, School of Public Health, Los Angeles, California; the ‡Canadian Memorial Chiropractic College, Toronto, Ontario; and the §Los Angeles College of Chiropractic, Whittier, CA; ∥Palmer College of Chiropractic-West, San Jose, CA; and ¶West Los Angeles Veterans Affairs Medical Center, Los Angeles, California.
Supported in part by a grant from the Consortium for Chiropractic Research.
Dr. Shekelle is a Research Associate of the Veterans Affairs Health Services Research and Development Service.
All of the conclusions in this paper are those of the authors and do not necessarily reflect the views of RAND or of the Consortium for Chiropractic Research.
Acknowledgment date: January 31, 1995.
First revision date: August 19, 1995.
Acceptance date: November 13, 1995.
Device status category: 1.
Address reprint requests to: Eric L. Hurwitz, DC, PhD; School of Public Health; Department of Epidemiology; 73-318 Center for Health Sciences; University of California, Los Angeles; Los Angeles, CA 90095-1772