Exhibit 23(b) CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation in this registration statement on Form F-4, 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 this registration statement. /s/ Arthur Andersen LLP Melville, New York February 3, 2000