Exhibit 23 Consent of Arthur Andersen LLP CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in the registration statement on Form S-8, No. 333-66117 of our report dated February 17, 1999, included in Healthworld Corporation's Annual Report on Form 10-K for the year ended December 31, 1998, and to all references to our Firm included in the registration statement. /s/ Arthur Andersen LLP Melville, New York March 25, 1999